Preventing aircraft ground handling delays

PREVENTING AIRCRAFT GROUND HANDLING DELAYS IN VIETNAM AIRLINES In Partial Fulfillment of the Requirements of the Degree of MASTER OF BUSINESS ADMINISTRATION In International business By Mr. Nguyen Le Phuong ID: MBA03025 International University – Vietnam National University HCMC February 2013 Preventing aircraft ground handling delays in Vietnam Airlines PREVENTING AIRCRAFT GROUND HANDLING DELAYS IN VIETNAM AIRLINES In Partial Fulfillment of the Requirements of the Degree of MASTER OF BUSINESS ADMINISTRATION In International business by Mr: Nguyen Le Phuong ID: MBA03025 International University – Vietnam National University HCMC February 2013 Under the guidance and approval of the committee, and approved by all its members, this thesis has been accepted in partial fulfillment of the requirements for the degree. Approved: .............................................. .............................................. Assoc. Prof. Ho Thanh Phong Committee member .............................................. .............................................. Committee member Committee member .............................................. .............................................. Committee member Committee member 2 Preventing aircraft ground handling delays in Vietnam Airlines Acknowledge First of all, I wish to express my sincere gratitude to my supervisor Assoc. Prof. Ho Thanh Phong for inspiring me this interesting topic and sharing his great knowledge, priceless input and documents help during my research. I specially want to express thankfulness to my colleagues, friend, who support, encourage and share idea to me during the time I do the research. Last but not least, I want to say thankful to my family, especially my mother who always beside me and give me power to complete my dissertation. It has been an honor to have a chance working with all the people involved during the research period and a great learning experience for me. With many thanks, 3 Preventing aircraft ground handling delays in Vietnam Airlines Plagiarism Statements I would like to declare that, apart from the acknowledge references, this thesis either does not user language, ideas, or other original material from anyone; or has not been previously submitted to any other educational and research programs or institutions. I fully understand that any writings in this thesis contradicted to the above statement will automatically lead to the rejection from the MBA program at the International University – Vietnam National University Ho Chi Minh City. 4 Preventing aircraft ground handling delays in Vietnam Airlines Copyright Statement This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognize that its copyright rests with its author and that no quotation from the thesis and on information derived from it may be published without the author’s prior consent © Nguyen Le Phuong/ MBA03025/ 2013 5 Preventing aircraft ground handling delays in Vietnam Airlines Table of Contents Table of Contents.......................................................................................................................6 Chapter one – Introduction ......................................................................................................13 1.1 Research background ................................................................................................13 1.2 Problem statement .....................................................................................................14 1.3 Research objectives ...................................................................................................15 1.4 Research structure .....................................................................................................15 Chapter two - Literature Review..............................................................................................16 2.1 Definition of Aircraft Ground Handling ...................................................................16 2.2 Aircraft Ground Handling in VNA at TSN Airport ..................................................17 2.3 Modeling of turnaround process using petri nets ......................................................19 2.4 Impact of analysis tools on aircraft turnaround processes ........................................23 2.5 Ideas to improve ground handling operations ...........................................................24 2.6 Apply theory of constraints and critical path to turnaround time .............................25 2.7 Aircraft ground handling and human factors ............................................................27 2.8 Ground handling Cost ...............................................................................................28 Conclusion............................................................................................................................30 Chapter Three - Research methodology ..................................................................................31 3.1 Research design.........................................................................................................31 3.2 Research process .......................................................................................................32 3.3 Data Collection..........................................................................................................33 3.4 Data analysis .............................................................................................................33 3.4.1 Critical path method...........................................................................................33 3.4.2 Seven basic tool of quality.................................................................................36 3.4.3 Flow chart ..........................................................................................................38 ..........................................................................................................................................40 3.4.4 Fault tree analysis ..............................................................................................41 3.4.4 Descriptive statistics ..........................................................................................47 3.4.5 Multiple linear regressions.................................................................................47 3.4.6 Reliability simulation and test mode..................................................................48 Chapter 4 - Research Finding ..................................................................................................49 6 Preventing aircraft ground handling delays in Vietnam Airlines 4.1 Defects analysis.........................................................................................................49 4.1.1 ‘Late cockpit crew’ defect .................................................................................49 4.1.2 ‘Refueling tanker positioning late’ defect..........................................................63 4.1.3 ‘Late cabin crew’ defect.....................................................................................68 4.1.4 ‘Move aircraft from hangar to parking late” defect ...........................................72 4.1.5 Calculate FTA....................................................................................................77 4.2 Ground Handling Cost ..............................................................................................78 Chapter five - Research conclusion & Recommendation ........................................................79 5.1 Research conclusion..................................................................................................79 5.2 Recommendation.......................................................................................................80 5.3 Limitation ..................................................................................................................80 References................................................................................................................................81 7 Preventing aircraft ground handling delays in Vietnam Airlines List of Figures Figure 1: Aircraft ground handling operation in VNA ............................................................18 Figure 2: Conceptual model of the aircraft ground handling system.......................................20 Figure 3: Hierarchical graph of CPN model f turnaround process ..........................................21 Figure 4: Comparison of experiment 1 and experiment 2 simulation results ..........................22 Figure 5: Mean Aircraft Turnaround time improvem..............................................................23 Figure 6: Critical path 737-800................................................................................................26 Figure 7: Research process ......................................................................................................32 Figure 8: Critical path of turnaround ground handling for a passenger transport aircraft taking cargo.........................................................................................................................................35 Figure 9: Fish-bone diagram for delayed aircraft ground handling .........................................36 Figure 10: Control chart of On Time Departure Flights at TSN airport ..................................37 Figure 11: Departure flight’s defects .......................................................................................38 Figure 12: Aircraf ground handling flow chart at TSN airport................................................41 Figure 13: Fault tree model for aircraft ground handling ........................................................44 Figure 14: 'Cabin cleaning late' event ......................................................................................45 Figure 15: Normal distribution for 'late cock pit crew' defects before applying solutions ......53 Figure 16: Late cockpit crew defect.........................................................................................58 Figure 17: Normal distribution for 'late cock pit crew' defects after applying solutions.........59 Figure 18: Normal distribution for 'late refueling tanker' defects before applying solutions ..65 Figure 19: Late refueling tanker truck positioning ..................................................................66 Figure 20: Normal distribution for 'late refueling tanker' defects after applying solutions .....67 Figure 21: Normal distribution for 'late cabin crew' defects before applying solutions ..........70 Figure 22: Late cabin crew defect............................................................................................71 Figure 23: Normal distribution for 'late cabin crew' defects after applying solutions .............72 Figure 24: Normal distribution for 'late cabin crew' defects before applying solutions ..........74 Figure 25: Late moving aircraft from hangar to parking .........................................................75 Figure 26: Normal distribution for 'late cabin crew' defects after applying solutions.............76 8 Preventing aircraft ground handling delays in Vietnam Airlines List of Table Table 1: Turnaround ground handling process design specifications for a new narrow body turnaround ground handling concept for the 737-800 .............................................................26 Table 2: Implementation plan for a new narrow body turnaround ground handling concept based on the 737-800 ...............................................................................................................27 Table 3: Number of Departure Flight’s defects .......................................................................43 Table 4: 'Late cockpit crew' defect's data ................................................................................51 Table 5: 'Late cockpit crew' defect with mean = 50.58 and standard deviation = 23.82 .........57 Table 6: 'Late cockpit crew' defect with mean = 20.5 and standard deviation = 8.3 ...............63 9 Preventing aircraft ground handling delays in Vietnam Airlines List of Appendix Appendix 1...............................................................................................................................83 Appendix 2...............................................................................................................................84 Appendix 3...............................................................................................................................86 Appendix 4...............................................................................................................................88 Appendix 5...............................................................................................................................89 Appendix 6...............................................................................................................................91 Appendix 7...............................................................................................................................93 Appendix 8...............................................................................................................................94 Appendix 9...............................................................................................................................96 10 Preventing aircraft ground handling delays in Vietnam Airlines Glossary VNA Vietnam Airlines TOC TAN SON NHAT Operation Center OCC Operating Control Center VAECO VNA Engineering Company VINAPCO Vietnam Air Petrol Company TIAGS TSN International Airport Ground Service VN/CX Vietnam Catering FCD 919 Flight Crew Divisions SITATEX Critical operations for airlines, ground handlers, global distribution system, airfreight and aerospace companies TSN Tan Son Nhat airport VIP Very important person ATC Air traffic control SAC Southern Airport Corporation SRO Southern Region Office 11 Preventing aircraft ground handling delays in Vietnam Airlines Abstract Punctuality is one of the key performance indicators in the airline industry and an important service differentiator especially for valuable high-yield customers. In addition, improved on-time performance can help achieve significant cost savings. Airlines report delay costs from 0.6 to up to as much as 2.9% of their operating revenues. VNA stated that they want to convey passengers or freight from one point to another with maximum safety, efficiency and on time performance. However, within 12.34% of delayed flights in 2011due to aircraft ground handling (annual report’s TOC), VNA operation is not very effectively in aircraft ground handling. The project is about aircraft ground handling process in VNA. Aircraft ground handling is a key component of the air transport logistics supply chain as it facilitates the mobility of cargo and people from one destination to another. Delays in movement of cargo and passengers at the airport are costly to passengers, businesses and the economy. Thus the project aims to build the model that analyze all aircraft ground handling operations, look for the critical factors that effect on flight delay and find out the final effect in flight delay if those factors are controlled. This report further describes the methodology of how to structure the project, and a project plan with a time schedule is given. Keywords: delay, aircraft ground handling, punctuality 12 Preventing aircraft ground handling delays in Vietnam Airlines Chapter one – Introduction This chapter introduces the research background, problem statement, research objectives and built up research question to show what problem that we should be solves. 1.1 Research background VNA was established by the Vietnam government in 1956. It was officially established as the national flag carrier of Vietnam in 1993. Currently, VNA operates flights to 35 international destinations in Asia, Australia, Europe and the Middle East, and to 18 domestic destinations in Vietnam. With a modern fleet of aircraft (including 6 Airbus A320s, 30 Airbus A321s, 9 A330s, and 10 Boeing 777s, 14 ATRs 72 and 2 Fokker 80s), VNA provides service with traditional Vietnamese hospitality ensuring passengers have the best possible introduction to the wonderful and vibrant country of Vietnam. Having recently redesigned their business class cabin VNA is now able to provide luxury travel to compete with many of the larger international airlines. Serving European destinations such as Paris and Frankfurt as well as cities in America and all over Asia, and through partnerships with airlines such as Qantas, Cathay Pacific, and Korean Airlines, VNA is making the country of Vietnam a more accessible destination whether for a short break or a longer period of travel. From 2010 to 2012, VNA has increased the on time percentage for departure flights at TSN airport dramatically. On time performance means that actual arrival and departure times must be within 15 minutes of the published schedule. Many factors can affect punctuality performance, including aircraft ground handling, timeliness of passengers, and aircraft arrival times on connecting flights. According to TOC which represents for VNA at TSN airport, in 2011, there were 4477 delayed and cancelled flights upon 64012 flights operated by VNA (approximately 18.05% of total flights). Many causes of delays are outside the responsibility of the VNA such as 13 Preventing aircraft ground handling delays in Vietnam Airlines weather, airport authorities and air traffic control. However, some delays are controllable; for example: ground handling, aircraft maintenance and flight or cabin crew rotation. On top of the negative impact on customer satisfaction, delays are expensive. Direct and indirect delay costs typically range from 0.6% to 2.0% of revenue, depending on the size and type of operation. Thus, punctuality should rank high on top-management’s agenda and to be a leadership challenge throughout the organization from strategy and planning all the way to frontline operations. 1.2 Problem statement When flights are on time, it is good for passengers and also helps the airlines' bottom lines. The passenger’s choice of airlines may be affected by the on-time arrival experience of passengers. The passengers may show stronger reaction (switch to other airlines) when they realize utility losses (service level below their expectation) than when they experience utility gains (service level above their expectation).More importantly, punctual airlines appear to be more profitable. According to AEA (the Association of European Airlines) a top-10 carrier performing carries $100 to $400 million in annual delay costs and for each percentage point improvement in punctuality there is a potential profit improvement of $4 to $16 million, depending on the size of the airlines. In 2011, there were 3978 delayed flights upon 64012 flights operated by VNA (approximately 12.34% of total flights) due to aircraft ground handling (annual report’s TOC).VNA always focuses on Direct Operating Cost (DOC), because DOC include ground handling costs, depreciation, interest, insurance, fuel costs, crew costs, maintenance costs, landing fees and navigation fees. For airlines, flights delay mean increase turnaround time and DOC as well. In VNA, the major source of flight delays at TSN airport is aircraft ground handling, usually by causing mistakes or wrong activities. 14 Preventing aircraft ground handling delays in Vietnam Airlines Within this research, it is focused on ground handling services analyzing to prevent the flight delays. 1.3 Research objectives The objectives of the research project are to:  To identify factors that cause delay in aircraft ground handling.  To evaluate effect of wrong activities in aircraft ground handling.  To develop a model for integrating all aircraft ground handling malfunction.  To control flight delay and reduce Direct Operating Cost in flights. 1.4 Research structure This thesis comprises 5 chapters as below: Chapter 1: Introduction This chapter introduces the research background, problem statement, research objectives and built up research question to show what problem that we should be solves. Chapter 2: Literature review This chapter introduces the conceptual framework aircraft ground handling in VNA at TSN airport and some key theories concept support for this study. Chapter 3: Research methodology This chapter focuses on the methodology for this study in terms of research design, research process, data analysis and the statistical method that was used for this research Chapter 4: Research Finding This chapter support data analysis and present outcome of research result. 15 Preventing aircraft ground handling delays in Vietnam Airlines Chapter 5: Research conclusion & Recommendation This chapter proposes some conclusions and as a result of finding and significant of study, researcher recommends some solution to solve the problem mentioned. Chapter two - Literature Review This chapter introduces the conceptual framework aircraft ground handling in VNA at TSN airport and some key theories concept support for this study. 2.1 Definition of Aircraft Ground Handling After aircraft is parked and chocks are put, turnaround process begins. The turnaround of an aircraft comprises the sequence of ground operations required to service the aircraft between two flights, from the time the chocks (rubber blocks to prevent aircraft from moving) are put in front of the wheels after it lands, to the time the chocks are removed and the aircraft is ready to leave. Many different organizations are involved in the turnaround process making it a complex and often inefficient operation. There are a number of key tasks carried out during and aircraft turnaround such as: loading and unloading passengers and baggage, safety and security checks, catering replenishment, cleaning and the completion of essential post and pre-flight administration. It should be noted that the servicing arrangements and turnaround tasks vary for different aircraft and different operators. The turnaround processes are typically shared between several organizations and it is essential that they work together effectively to deliver the optimal turnaround. This is further complicated when the aircraft is being handled at a remote airport by third party ground handling organizations. 16 Preventing aircraft ground handling delays in Vietnam Airlines 2.2 Aircraft Ground Handling in VNA at TSN Airport Ground handling help to address service requirements of an airliner between the time it arrives at a terminal gate and the time it departs on its next flight. Speed, efficiency, and accuracy are very important in ground handling services in order to minimize the turnaround time. Aircraft ground handling includes services on the ramp such as: a. Guiding the aircraft into and out of the parking position. b. Air-bridge positioning/removal. c. Towing with pushback tractors. d. Lavatory drainage. e. Water cartage. f. Air conditioning. g. Air starts units. h. Luggage handling. i. Gate checked luggage. j. Air cargo handling. k. Catering trucks. l. Refueling tanker truck. m. Ground power. n. Passenger stairs. o. Wheelchair lifts. 17 Preventing aircraft ground handling delays in Vietnam Airlines These services are belonged to VNA members such as: TIAGS, VAECO, VN/CX, FCD 919, Flight Attendant and VINAPCO. TOC is able to verify what flight is at what gate through SAC, the time the flight arrived and the time the flight is scheduled to depart via OCC. Hence, TOC forward this flight information to each VNA member by SITATEX and monitor the progress of each flight. Figure 1: Aircraft ground handling operation in VNA VNA Operations said that it costs them too much money for every minute that a flight is delayed. It is important to note that, for an airline, the “value” of delay is not just its effect on an individual airframe but its effect on the operating schedule. Passengers do not go out to the airport to fly on a specific airplane. They go to catch the one o’clock flight to Da Nang 18 Preventing aircraft ground handling delays in Vietnam Airlines which is promised in the airline’s published schedule. Hence, controlling wrong activities in aircraft ground handling also control flight delay, minimize operating costs and build trust in passengers. The aim of this study is to identify and investigate ideas to improve aircraft ground handling and control flight delay in VNA. 2.3 Modeling of turnaround process using petri nets When aircraft turnaround is finished and aircraft is ready to leave according to schedule, aircraft pilot contacts ATC and waits for the clearance to begin push-back procedure. Figure 2 below illustrates the conceptual model of the system. 19 Preventing aircraft ground handling delays in Vietnam Airlines Figure 2: Conceptual model of the aircraft ground handling system 20 Preventing aircraft ground handling delays in Vietnam Airlines According to Anna Norin (2008), it is found that one of the things making the logistics at an airport complex is the large number of actors involved, as well as the many activities that are sensitive to time. One very time sensitive process, where almost all of the actors are involved, is the turn-around process, which makes it a key process for airport logistics. With some adjustment, it will be possible to use the optimization algorithm developed for scheduling de-icing trucks, even for the other activities in turnaround process. Implementing optimized schedules for all the activities will give an even more complete picture of airport logistics, showing how all actors and processes are linked to each other and resulting in minimum aircraft delay. There were many different models of the aircraft turnaround process that have been developed in order to investigate its sensitivity to changes of available resources, aircraft arrival delays, different gate assignment strategies. The specific class of Petri Nets used is the Hierarchical Stochastic Colored Timed Petri Nets (CPN). Petri Nets are a graphical and mathematical modeling tool. Figure 3: Hierarchical graph of CPN model f turnaround process The highest hierarchical level called Entry/Exit which models: aircraft arrival (ENTER), parking, entering turnaround process queue, push back and departure (EXIT). The two subnet of hierarchy level 2, START is used for data input (schedule arrival time, aircraft type, and schedule departure time); Turnaround process, models all activities of aircraft 21 Preventing aircraft ground handling delays in Vietnam Airlines turnaround process and it is connected with two hierarchies level 3 subnets: Service and Bellyhold unloading, which models ground service and cargo/baggage handling activities. Experiments differ in terms of gate-assignment strategy. The first experiment gates were dedicated to aircraft according to gate assignment plan, while in the second were automatically assigned during aircraft arrival. Scenario 2 assumes lack or failure of ground handling equipment. Scenario 3 assumes aircraft arrival time as a random variable with uniform distribution (schedule time +/- 5 minutes). Scenario 4 assumes variable passenger deplaning and boarding time such as late transfer passengers. Through analysis it has been clear that gate-assignment strategy where gates are dedicated to aircrafts according to gate assignment plan leads to additional delays when operations are perturbed. Departure delay as well as turnaround process is always smaller when using automatic assignment strategy than using strict gate assignment strategy. This is a great importance, especially at hub airports where most of the passengers are transfer passengers whose inbound flights delays will cause delays of outbound flights. Moreover, the change of gate assignment close to aircraft arrival will usually result in a longer turnaround (need to transfer outbound baggage, cargo and passengers ...). Figure 4: Comparison of experiment 1 and experiment 2 simulation results 22 Preventing aircraft ground handling delays in Vietnam Airlines 2.4 Impact of analysis tools on aircraft turnaround processes The tools, which include single-minute exchange of dies, lean manufacturing processes and critical path have been examined and applied to aircraft turnarounds. Single-Minute Exchange of Die (SMED) is one of the many lean production methods for reducing waste in a manufacturing process. It is a concept that focuses on improving machine setups: internal setup (tasks that can only be performed when a machine has stopped) and external setup (tasks that can be carried out while the machine is in operation). Applied to aircraft turnaround time, where an aircraft turnaround is seen as a setup operation (Tasks carried out while the plane is on the ground are the internal setup and external setup refers to activities which may be carried out before the plane lands). Lean manufacturing is a philosophy of production that emphasizes the minimization of the amount of resource (including time) used in the various activities of the enterprise. Lean manufacturing involves identifying and eliminating non value adding activities and focuses on the start-to-end values streams rather than the idea of optimizing individual departments in isolation. Waste is a term frequently associated with lean manufacturing and the focus should be on preventing waste rather than eliminating it. Thus, the principle of lean manufacturing can be applied to aircraft turnaround. Approach to mean turnaround time improvement by using Identification Technologies (ID) as well as the SMED and Critical Path consists of three main steps: Figure 5: Mean Aircraft Turnaround time improvement 23 Preventing aircraft ground handling delays in Vietnam Airlines Step 1: Get an overview of the turnaround operations, the timings of these operations, the technology and information currently used. Using the information collected, a Gantt chart and the critical path for the ideal/minimum turnaround was produced for each airline. Step 2: Critical path processes; more in-depth understanding of the processes. This was achieved by walking through the processes, watching them in real time, speaking to cabin and flight deck crew, ground and operations staff. Step 3: Areas for the application of ID technologies; Areas where critical path processes could be improved and areas where the time of these processes could be reduced by using ID technologies were identified. Numbers of areas within the critical path of the turnaround were identified (Boarding, Cleaning/Security, Technical delays). Technical delays and late loading cause a significant disturbance to the turnaround. These tasks are typically carried out by partner organizations and require timely, accurate information to be effective. ID technologies show that the information systems and business processes for sharing this information between partners are essential. 2.5 Ideas to improve ground handling operations According to Gomez, F. &Scholz, D. (2009), Speed, efficiency and accuracy are important in ground handling operations in order to minimize turnaround time and ground handling costs. Improvement to ground handling operation always aim at reducing turnaround time and ground handling costs, if improvements to ground handling operations also reduce Direct Operating Costs (interest, insurance, fuel costs, maintenance costs, crew costs, landing fees and navigation fees). 24 Preventing aircraft ground handling delays in Vietnam Airlines The turnaround times are dramatically decreased with the automatic pushback system, the airstairs and the installation of a main third door for passengers in the airplane. Automatic pushback system avoid the tractor for the pushback operation -> the ground handling costs could be reduced because ground handling fees can be reduced and additional time and fuel could be saved. Airstairs decrease ground turnaround times and save deboarding/boarding operation cost. With airstairs no ground services are necessary. Third door saves a lot of time in boarding/deboarding operations. This time-saving has a great importance in the low cost airlines’ turnaround process; where boarding and deboarding take part on the critical path. All the modifications to ground handling costs may have a positive influence on the DOC of the aircraft. In the best-case scenario, the benefit in DOC per flight could rise to 3.45% if all the compatible modifications to ground handling operation are taken into account simultaneously. 2.6 Apply theory of constraints and critical path to turnaround time The Theory of constraints and critical path analysis showed that in the normal flight, the duration of cabin activities determines the total turnaround time. It also means the critical paths lie in the cabin. 25 Preventing aircraft ground handling delays in Vietnam Airlines Figure 6: Critical path 737-800 This research used GDR (Group Decision Room) brainstorm session as basic for developing suggestions and possible solutions to improve the turnaround ground handling processes. Table 1: Turnaround ground handling process design specifications for a new narrow body turnaround ground handling concept for the 737-800 26 Preventing aircraft ground handling delays in Vietnam Airlines Besides shortening the critical path activities, environment, safety, security and flexibility have been taken into account. Table 2: Implementation plan for a new narrow body turnaround ground handling concept based on the 737-800 The implementation plans for B737-800 is shown in table 3 and the turnaround time can be reduced with 42% due to the concept specifications. 2.7 Aircraft ground handling and human factors The aim of this study is to investigate the causal factors which lead to human errors during the ground handling process, creating unsafe situations, personal accidents or incidents. ‘Seven Ground Service Provides’ have been invited to participate into human factors in ground handling. Questionnaires have been distributed to two target groups: 172 for Management (management, department head, supervisor and support) and 1102 for 27 Preventing aircraft ground handling delays in Vietnam Airlines Operational personnel (coordination, team leaders and ramp personnel). The response rate is divided into: management is 57% and Operational personnel are 19%. The first section of the questionnaire aims to assess the safety culture of each GSP; the second section focuses on human factors. When the results of management and operational personnel are compared on the overall level, management generally provides a higher rating than operational for the safety culture characteristics and indicators. Personal factors that occur most frequent in the views of Management and Operational personnel are time pressure, stress and fatigue. There are differences between the views of management and operational personnel with regard to the contributing factor Equipment/tools/safety equipment. Management seeks the contributing factors of human errors and incidents in incorrect use, or lack of use of the ground handling equipment or personal protective equipment. Operational personnel expresses the view that bad maintenance, poor reliability and poor safety of the equipment contributes to errors and incidents. It is important for management to be aware of the importance of ground handling equipment to the operational personnel. 2.8 Ground handling Cost When a company wants to buy a new aircraft the aspects which have an important influence on the acquisition of the aircraft are the following ones: (Martinez-Val 2007)  Aircraft economics: o Direct Operating Costs (DOC) o Aircraft price  Aircraft performances: o Payload-range Diagram 28 Preventing aircraft ground handling delays in Vietnam Airlines o Cruise speed o Performances in runway: take-off distance, landing distance... o Performance with critical engine inoperative  Manufacture: o Previous experience o Product support o Financing conditions o Delivery period  Other aspects: o Appeal to the passenger (cabin distribution, comfort, ...) o Aircraft family o Noise, pollution, ... In order to make a cost analysis, there are a whole series of models for cost analysis, such as LCC (Life Cycle Costs), COO (Cost of Ownership) or DOC (Direct Operating Cost). Each method has a different concept about costs and its calculation and has an approach from different perspectives. (Scholz 2010). According to the purpose of the study is aircraft ground handling, researcher will focus on DOC method. Direct operating costs which are involve during the utilization of an aircraft by a company for one determined route during a defined time period. As a rule, DOC methods calculate the direct operating costs of an aircraft from the cost C incurred to: 29 Preventing aircraft ground handling delays in Vietnam Airlines  Depreciation  Interest  Insurance  Fuel  Maintenance  Crew o Cabin crew o Cockpit crew  Fees and charges o Landing fees o ATC charges o Ground handling charges Then, the DOC is the sum of these cost elements: CDOC = CDEP + CINT + CINS + CF + CM + CC + CFEE Conclusion The literature review has revealed the background to aircraft ground handling, ground handling cost, the modeling of the aircraft turnaround process, ideas to improve ground handling operations, methods for reduction in mean turnaround times and human factors in aircraft ground handling. Review of literature on the concept of the system show that the main issue is to be on time in terms of minimum turnaround times, but ground handlers in 30 Preventing aircraft ground handling delays in Vietnam Airlines VNA usually have wrong activities and mistakes. Aircraft modifications or new ground equipment may improve aircraft ground handling in advance. However, the ground handling costs are a tough question for VNA due to the fact that capital, human resources and management are not easy to answer. Thus, the study thinks to develop models which keep all wrong activities in turnaround process at minimum. Chapter Three - Research methodology This chapter focuses on the methodology for this study in terms of research design, research process, data analysis and the statistical method that was used for this research 3.1 Research design According to White (2005) research design is the term that consist of the aims, the selection of appropriate methodology that suit and fit with the literature of the research (White, 2005). Thus, based on the objective of the research, research design gives a guidance to collect the data and how to analysis those data (Churchill, 1979). There are two types of methods of research, which are normally the most used in the collection of data; there are identified as following: quantitative and qualitative methods. According to Mark and Philip (2007), the quantitative methods are used for any data collection technique (such as questionnaires) or data analysis procedure (such as graphs or statistics). Data is collected and transformed into numbers, which are empirically tested to see if a relationship can be found in order to be able to draw conclusions from the results gained. In order words, quantitative methods are related to numerical interpretations. On the other hand, qualitative research does not rely on statistics or numbers. Qualitative methods are used for data collection technique (such as an interview) or data analysis procedure (such as categorizing data). Furthermore, 31 Preventing aircraft ground handling delays in Vietnam Airlines qualitative research is an appropriate approach for research in business and management administration, The type of research approach to select depends on the kind of studies that will be conducted. Applying quantitative method will be more suitable in order to fulfill the purpose of this research, since this study is researching how control delay in aircraft ground handling, due to the fact that data analysis procedure (such as graph or statistics) are difficult to measure in a qualitative way. This study identifies the factors caused delay in VNA flights especially in ground handling services, how those factors link together and the effect of each factor in overall process. Then set up a model based on the fault tree analysis method for modeling malfunctions of aircraft ground handling and find out the final effect if every component is this model is controlled. 3.2 Research process Figure 7: Research process 32 Preventing aircraft ground handling delays in Vietnam Airlines 3.3 Data Collection Collecting data can be either primary or secondary. Primary data is information that researcher gathers on his’ own, for instance by using interviews, questionnaires and tests. On the other hand, secondary data refers to the sources such as literature, documents and articles that are collected by other researchers and institutions. In this thesis, secondary data were collected. The secondary data used has been critically evaluated and collected from company reports, books, scientific articles in order to obtain, collect, statistic and analyze all relevant data of each ground delay case that caused by the Vietnam Airline’s company members during the last three years to find out the more frequent points and set up a model for controlling those points based on above information. Last but not least, due to the advantage of internet source such as the researcher can access easily and quickly about various types of information; it is used to help researcher achieving practical understanding more of aircraft services. 3.4 Data analysis 3.4.1 Critical path method The critical path method (CPM) is a project modeling technique developed in the late 1950s by Morgan R. Walker of DuPont and James E. Kelley, Jr. of Remington Rand.Kelley and Walker related their memories of the development of CPM in 1989. The critical path is the sequence of activities which defines the total time of a project. These mandatory activities must be completed before other activities can commence. In consequence they are critical and any delay in them would increase the total time of the project. The following activities are likely to be on the critical path.  Critical activities. 33 Preventing aircraft ground handling delays in Vietnam Airlines  Activities dependents on critical activities.  Overall engagement times for each activity. In aircraft ground handling, the critical path consists of the passenger and aircraft cabin activities (i.e. passenger disembarkation, cabin cleaning and passenger embarkation), some of them cannot be carried out at the same time like disembarking and embarking but in other instances, the critical path is also caused because of safety regulations (i.e. refueling cannot start until the end of disembarking and embarking cannot star until the end of refueling). There are also some circumstances when other operations may become the critical path, due to the fuel load or the capacity of the cargo loader. Other activities, such as water service can normally be performed without impact from the critical path. 34 Preventing aircraft ground handling delays in Vietnam Airlines Position wheel chocks Start minute: 0 Finish minute: 2 Position passenger steps/jet way Start minute: 2 Finish minute: 3 Position conveyor door Position liftloader door Open passenger door Start minute: 5 Start minute: 5 Start minute: 5 Finish minute: 3 Finish minute: 3 Finish minute: 1 Open baggage door Open cargo door Passengers deplane Start minute: 8 Start minute: 8 Start minute: 6 Finish minute: 1 Finish minute: 1 Finish minute: 15 Baggage unloading Cargo unloading Crew deplane and Board crew Fueling Start minute: 9 Start minute: 9 Start minute: 21 Start minute: 21 Finish minute: 10 Finish minute: 20 Finish minute: 3 Finish minute: 20 Baggage loading Cargo loading Catering, in-flight entertainment Cabin cleaning Start minute: 19 Start minute: 29 Start minute: 24 Start minute: 24 Finish minute: 40 Finish minute: 50 Finish minute: 20 Finish minute: 27 Close door Close cargo door Security check Start minute: 59 Start minute: 79 Start minute: 51 Finish minute: 1 Finish minute: 1 Finish minute: 5 Remove conveyor door Remove liftloader door Board passengers Start minute: 60 Start minute: 80 Start minute: 56 Finish minute: 1 Finish minute: 1 Finish minute: 27 Close passenger cabin door Start minute: 83 Finish minute: 1 Remove passenger steps/ jet way Start minute: 84 Finish minute: 3 Remove chocks Start minute: 87 Finish minute: 2 Figure 8: Critical path of turnaround ground handling for a passenger transport aircraft taking cargo 35 Preventing aircraft ground handling delays in Vietnam Airlines 3.4.2 Seven basic tool of quality Quality tools are used by organization to help monitor and manage quality initiatives. There are several types of tools used but there are seven management tools for quality control that are the most common. Different tools are used for different problem solving opportunities and many of the tools can be used in different ways. The tools in this study are: Cause-and-effect diagram (also called Ishikawa or fishbone chart): Figure 9 identifies many possible causes for delay aircraft ground handling and sorts ideas into ‘material’, ‘personnel’, ‘machine’ and ‘other’ categories. Causes are identified through brainstorming with a group familiar with the problem. Once all causes are identified, they can be used to develop and improvement plan to help resolve the identified problem. Figure 9: Fish-bone diagram for delayed aircraft ground handling 36 Preventing aircraft ground handling delays in Vietnam Airlines Control charts: Control charts or run charts plot data points on a line over time and give a picture of data movement. It demonstrates when data is consistent or when there are high or low outliers in occurrences of data. In this study, control charts are displayed by figure 11 that used to study how punctuality of VNA changes from 2010 to 2012. Figure 10: Control chart of On Time Departure Flights at TSN airport Pareto chart: A pareto chart is a bar graph of data showing the largest number of frequencies to the smallest. 37 Preventing aircraft ground handling delays in Vietnam Airlines Figure 11: Departure flight’s defects When looked at from the largest to the smallest occurrences, it is an easy picture to see this study must eliminate or decrease ‘late cockpit crew’, ‘refueling tanker positioning late’, ‘late cabin crew’, ‘move a/c from hangar late’ and ‘chock on late’ defects in order to improve aircraft ground handling. These defects will be presented in chapter 4. 3.4.3 Flow chart Flow charts are easy-to-understand diagrams showing how steps in aircraft ground handling fit together. This makes them useful tools for communicating how processes work, and for clearly documenting how turn around activities is done. Furthermore, the act of mapping a process out in flow chart format helps the researcher clarify the understanding of the process, and helps think about where the process can be improved. The below flow chart shows steps in the VNA’s aircraft turn around ground handling at TSN airport. 38 Start Preventing aircraft ground handling delays in Vietnam Airlines Parking Engine shutdown N Choc k on? Contact TOC Contact VAECO Y Catering truck positioning Parking near station? Conveyor positioning N Lift-loader positioning Lavatory truck positioning Y Jet way positioning Contact VN/CX Passenger stairs positioning Portable water truck positioning Contact SAC N N Done ? Contact TOC Done ? Done ? N N Contact TIAGS Done ? Y Contact TOC Y Y Portable water jet way Y Baggage unloading Passenger deplane Unloading previous items (meals, water...) Provide meals, water... for next flight N Contact Flight Attendan Cargo unloading Lavatories service N Contact VINAPCO N Refueling tanker trucks positionin Contact TOC Y Contact 919 Installing fuel to aircraft N Check quality and Cabin cleanin Y Y Y Refueling tanker trucks removal Catering truck removal 4 1 2 3 5 39 1 2 Passenger Preventing aircraft ground handling delays in Vietnam Airlines Boarding Y Last minute CAT Last minute passenge rs N 4 3 Baggage loading Y Offload baggage and passenger Y 5 Cargo loading Passenger’s baggage do not show up on the aircraft N N Conveyor removal Jet way or passenger stairs removal Lift-loader removal Chock off Is departure time come? N Y Is apron Taxiway empty? N Y Push-back Finish 40 Lavatory truck removal Preventing aircraft ground handling delays in Vietnam Airlines Figure 12: Aircraft ground handling flow chart at TSN airport 3.4.4 Fault tree analysis Fault tree analysis (FTA) is a top down, deductive failure analysis in which an undesired state of a system is analyzed using Boolean logic to combine a series of lowerlevel events. This analysis method is mainly used in the field of safety engineering and Reliability engineering to determine the probability of a safety accident or a particular system level (functional) failure. Based on conceptual framework of the aircraft ground handling, a FTA’s model is built. FTA analysis involves four steps: a. Define the undesired event to study This study defines of the undesired event based on report and observe. A ramp executive with a wide knowledge of the aircraft ground handling operations help define and number the undesired events. In this study, an undesired event is flight delay. b. Obtain an understanding of the system Once the undesired event (flight delay) is selected, all causes with probabilities of affecting the undesired event of 0 or more are studied and analyzed. Getting exact numbers for the probabilities leading to the event is usually impossible for the reason that it may be very costly and time consuming to do so. Fortunately, researcher has all reports of aircraft ground handling’s errors at TSN airport from 2010 to 2012. Thus, all causes affecting the flight delay are collected and statistic as below. 41 Preventing aircraft ground handling delays in Vietnam Airlines VAECO Errors Percentage 1.Late chock on 5 1.17% 2. Move a/c from hangar to parking late 45 10.56% 4. Late catering truck positioning 11 2.58% 5. Last minute CATS 13 3.05% 6. Late cockpit crew 150 35.21% 7. Incorrect fuel information 18 4.23% 8. Late cabin crew 58 13.62% 9. Check CAT’s quality and quantities 6 1.41% 10. Late offload passenger 17 3.99% 11. Late luggage 16 3.76% 12. Late transfer bus 1 0.23% 13. Late conveyor positioning 0 0.00% 14. Late lavatory positioning 0 0.00% 15. Late Lift- loader positioning 0 0.00% 16. Late Passenger stairs 0 0.00% 68 15.96% 14 3.29% VN/CX 919 FA TIAGS VINAPCO 17. Late refueling tanker positioning SRO 18. Late air cargo 42 Preventing aircraft ground handling delays in Vietnam Airlines 19. Cut cargo 4 0.94% 20. Lack of jet way staff 0 0.00% Total 426 100.00% SAC Table 3: Number of Departure Flight’s defects c. Construct the fault tree After having the undesired event (flight delay) and knowing all causing effects with their probabilities, researcher can now construct the fault tree by using OpenFTA software. OpenFTA is an advanced tool for fault tree analysis. It has an intuitive front-end which allows the user to construct, modify or analyze fault trees. OpenFTA has been designed to gain wide international acceptance for fault tree analysis, particularly in the aerospace, nuclear, medical equipment and defense fields. 43 Preventing aircraft ground handling delays in Vietnam Airlines Figure 13: Fault tree model for aircraft ground handling 44 Preventing aircraft ground handling delays in Vietnam Airlines d. Evaluate the fault tree After the fault tree has been assembled for a flight delay. It is evaluated and analyzed for any possible improvement. By using Boolean algebra and data from table 3: The OR-Gate: P(Q) = P(A) + P(B) – P(A∩B) = P(A) + P(B) – P(A)P(B|A) The AND-Gate: P(Q) = P(A)P(B|A) = P(B)P(A|B) Researcher can calculate the probability of punctuality flights: Figure 14: 'Cabin cleaning late' event By using the data in table 3, ‘move a/c from hangar to parking late’, ‘lack of staff’, ‘jet way technical’, ‘late chock on’ and ‘lack of step truck’ are basic events with the probabilities. Gate symbols are OR-Gate that means the ‘cabin cleaning late’ will occurs if any input such 45 Preventing aircraft ground handling delays in Vietnam Airlines as: ‘lack of staff’, ‘passenger deplane late’ and ‘move a/c from hangar to parking late’ occurs. Hence, its structure function is given by: (x) = max(x1,.........,xn)  P(Late cabin cleaning) = 1 – (1 – P(lack of staff)) * (1-P(Late chock on)) * (1 – P(Move aircraft from hangar to parking late)) * (1 – P(jet way technical)) * (1 – P(lack of step truck)) = 1 – (1 – 0) * (1 – 0.0117) * (1 – 0.1056) * (1 – 0) * (1 – 0) = 0.1161 Thus, these remaining events will be calculated for full fault tree model as below:  P(Late catering removal) = 1 – (1 – P(Late catering truck pos)) * (1 – P(Late cabin crew)) * (1 - P(Late chock on)) * (1 – P(Move aircraft from hangar to parking late)) * (1 – P(Check CAT’s quality and quantities)) = 1 – (1 – 0.0258) * (1 – 0.1362) * (1 –0.0117) * (1 – 0.1056) * (1 – 0.0141) = 0.2667  P(Late aircraft refueling) = 1 – (1 – P(Late refueling tanker pos)) * (1 – P(Late cockpit crew)) * (1-P(Late chock on)) * (1 – P(Move aircraft from hangar to parking late)) * (1 – P(Incorrect fuel information) = 1 – (1 – 0.1596) * (1 – 0.3521) * (1 – 0.0117) * (1 – 0.1056) * (1 – 0.0423) = 0.5391  P(Late passenger boarding) = 1 – (1 – P(Late catering removal)) * (1 – P(Late aircraft refueling)) * (1 – P(Late cabin cleaning)) = 1 – (1 – 0.2667) * (1 – 0.5391) * (1 – 0.1161) = 0.7013  P(Last minute passenger) = 1 – (1 – P(Late offload passengers)) * (1 – P(Late passenger boarding)) = 1 – (1 – 0.0399) * (1 – 0.7013) = 0.7132 46 Preventing aircraft ground handling delays in Vietnam Airlines  P(Late jet way removal) = 1 – (1 – P(Last minute CATs)) * (1 – P(Last minute passenger)) = 1 – (1 – 0.0305) * (1 – 0.7032) = 0.7219  P(Late lift-loader removal) = 1 – (1 – P(Late air cargo)) * (1 – P(Cut cargo)) = 1 – (1 – 0.0329) * (1 – 0.0094) = 0.0419  P(Late conveyor removal) = 1 – (1 – P(Late luggage)) * (1 – P(Late offload passenger)) * (1 – P(Late conveyor positioning)) = 1 – (1 – 0.0376) * (1 – 0.0399’) * (1 – 0 ) = 0.076  P(Late push-back) = 1 – (1 – P(Late conveyor removal)) * (1 – P(Late jet way removal)) * (1 – P(Late lift-loader removal)) = 1 – (1 – 0.076) * (1 – 0.7129) * (1 – 0.0419) = 0.7538  P(Punctuality flights) = 1 – P(Late push-back) = 1 – 0.7538 = 0.2462 Hence, the probability of punctuality flights (24.62%) is low based on Fault tree model and data from table 3. 3.4.4 Descriptive statistics “Descriptive statistics is one of the bridges between measurement and understanding”. We describe the data, find reliable differences or relationships, and estimate population values for the reliable findings. Typically the data are reduced down to one or two descriptive summaries like the mean and standard deviation or correlation, distributions. 3.4.5 Multiple linear regressions Multiple linear regression analysis is MRA a relatively straight-forward form of oneway Analysis of Variance (ANOVA) for two variables. Basically, it measure the degrees of difference between observed events, or “signal”, and the randomness, or “noise”, is lurking in the background. ANOVA essentially assesses how spread out the dispersion pattern of 47 Preventing aircraft ground handling delays in Vietnam Airlines individual data-points is both within and between these variables. When only two variables are being examined, this ratio’s calculation is relatively straight-forward and is known as the t-test (Evans, 1999). 3.4.6 Reliability simulation and test mode Because the reliability of each component is based on probability distributions, the reliability of each component in a system flow chart can be modeled by a set of random numbers. For instance, if the reliability of a component is 0.8, then successful operation of that component can be represented by the numbers from 0.0 through 0.79 and failure by the numbers from 0.8 through 0.99 (Amstadter, 1971, p. 176). By generating random numbers as the sys-tem flow chart is traced, it is possible to simulate the state of each component. These component states can then be combined using the structure function to determine the state of the system. Since “each execution of a simulation tells only whether a particular set of conditions did or did not” exist, the Monte Carlo method is an experimental problem-solving technique such that “many simulation runs have to be made to understand the relationships involved in the system” (Gordon, 1978, pp. 42, 43). Each repetition of the simulation results in another independent estimate of the reliability of the system. As the number of simulations increases, the sample mean of these indepen-dent estimates approaches the actual characteristics of the system (Amstadter, 1971, p. 176). According to Verma, Fu, and Moses,the Monte Carlo method computes the statistical expectation of the reliability distributions (Zaremba, 1968, p. 304). Thus, because estimates of system reliability are based on probability distributions functions representing the failure rates of components, the Monte Carlo method will accurately simulate system reliability whatever the complexity of those distributions, even in the case that they are entirely empirical. 48 Preventing aircraft ground handling delays in Vietnam Airlines The study found solutions to minimize defects that occur frequently in figure 6 by using knowledge, experience, brainstorm … After that, these defects will be tested to see whether the result is trusted or not. Once defects are tested, the study will calculate the FTA’s P (on time) again to make sure these solutions are effect. Chapter 4 - Research Finding This chapter support data analysis and present outcome of research result. 4.1 Defects analysis The study chooses defects that occur frequently based on figure 6. These defects are ‘late cockpit crew’, ‘late cabin crew’, ‘late refueling tanker positioning’ and ‘moving aircraft from hangar to parking late’. After analyzing these defects and find out the solutions to minimize these defects by using knowledge, brainstorm with expert, books and internet source, these defects will be tested by simulating to make sure those solutions can apply and work. 4.1.1 ‘Late cockpit crew’ defect Descriptive statistic of late cockpit crew Use the data of Table 4: T(late cockpit crew) 110 50 13 35 40 40 T(flight delay) 50 20 13 20 20 15 T(late cockpit crew) 30 20 20 30 35 5 T(flight delay) 15 10 15 27 18 5 T(late cockpit crew) 47 45 78 20 80 18 T(flight delay) 20 23 18 19 44 18 49 Preventing aircraft ground handling delays in Vietnam Airlines 30 35 35 47 37 15 32 60 25 30 50 90 37 45 55 50 55 50 80 55 40 80 50 47 35 45 90 46 45 60 20 30 90 18 20 25 30 30 40 50 76 10 35 88 10 15 17 25 25 15 15 15 15 20 25 60 20 25 25 25 15 25 47 15 20 20 20 15 20 15 30 35 20 20 10 16 65 18 20 15 20 15 20 20 43 5 35 28 38 51 25 85 63 50 55 80 65 50 27 68 60 75 50 10 40 20 52 15 74 30 96 70 50 10 50 120 5 75 73 150 72 23 20 25 50 55 105 5 80 65 30 25 15 20 18 48 25 22 20 40 20 25 18 35 20 15 20 5 17 19 16 15 14 16 65 58 38 5 15 60 5 15 38 94 40 23 15 22 25 33 60 5 39 45 20 18 55 30 30 75 140 75 60 30 100 57 56 20 45 80 43 50 84 43 35 97 30 15 55 35 40 30 68 25 20 25 5 20 15 60 80 75 50 55 15 120 35 40 60 58 15 16 23 40 85 40 35 19 43 30 14 15 20 39 15 25 50 20 17 60 23 10 15 10 25 20 35 20 15 15 5 15 10 20 40 44 26 15 15 60 10 28 25 30 50 Preventing aircraft ground handling delays in Vietnam Airlines Table 4: 'Late cockpit crew' defect's data The mean and standard deviation of T (late cockpit crew) are computed as below: Mean = 50.5822 Standard deviation = 23.8206 In aircraft ground handling operation of VNA at TSN airport, the cockpit crew must arrives at the aircraft at least an hour before departure (one hour and a half for VIP flights). Then they will reviews the information of the flight including the weather, the number of passengers on board; works out the flight plan; files it with air traffic control and meets with the rest of the crew and make sure all of the instruments and controls are working properly. Hence, the more time cockpit crew comes late to the aircraft, the more delay time flights are. Mean shows that the time for this defect takes almost one hour. Standard deviation indicates that the data points tend to be spread out over a large range of values. If this defect occurs, the time for cockpit crew come late to aircraft could be very large. Thus, flight could be delay more than one or two hours and it is not good for passenger and airline’s benefits because passengers wait their flight and VNA lost much money for DOC in one hour or two hours. Multiple linear regressions For each data of T (late cockpit crew), T (flight delay) is resulted in Table 4 because the cockpit crew activity belongs to critical path and any delay of this activity directly impacts the turnaround time. Hence, researcher uses multiple linear regression to model the relationship between T (late cockpit crew) and T (flight delay) by using data in Table 4. Predictor Coefficients Standard Error T stat P-value 51 Preventing aircraft ground handling delays in Vietnam Airlines T(late cockpit crew) 13.9028 0.8186 16.98 0 T(flight delay) 1.39156 0.02809 49.54 0 S = 13.4836 R-Sq = 70.2% R-Sq(adj) = 70.2% Analysis of variance Source DF SS MS F P Regression 1 446190 446190 2454,2 0 Residual Error 1042 189443 182 Total 1043 635633 The regression equation is: T (late cockpit crew) = 13.9 + 1.39*T (flight delay) Reliability simulation and test mode For mean = 50.5822 and standard deviation = 23.8206 52 Preventing aircraft ground handling delays in Vietnam Airlines Figure 15: Normal distribution for 'late cock pit crew' defects before applying solutions A set of 150 random numbers of T (late cockpit crew) as well as 150 errors of this defect are created. By using above equation of multiple linear regressions T (flight delay) = {T (late cockpit crew) – 13.9} / 1.39 Researcher computes the T (flight delay) and count error based on T (flight delay) again (positive = delay and negative = punctuality). Table 5 shows that, there are 142 errors after simulating and the result are accepted. T(late cockpit T(flight Error = Trial 50.58;23.82 T(flight Error = 53 Preventing aircraft ground handling delays in Vietnam Airlines crew) 110 50 30 35 40 40 30 35 35 47 37 30 32 60 25 30 50 90 37 45 55 50 55 50 80 55 40 80 50 47 35 45 40 46 45 60 20 30 90 35 20 25 30 delay) 50 20 13 20 20 15 10 15 17 25 25 15 15 15 15 20 25 60 20 25 25 25 15 25 47 15 20 20 20 15 20 15 30 35 20 20 10 16 65 18 20 15 20 150 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 59.25 72.25 80.84 73.00 36.75 65.61 30.11 36.06 88.66 69.66 41.59 61.60 6.65 58.36 62.27 35.18 55.435 29.82 63.19 60.38 61.32 44.95 29.36 37.71 117.35 -12.53 35.01 52.79 55.14 24.57 90.15 43.48 18.51 43.13 47.31 63.66 59.74 63.38 44.90 24.96 51.30 57.61 56.76 delay) 32.57 42.39 48.71 42.94 16.28 37.51 11.40 15.78 54.46 40.48 19.85 34.56 -5.85 32.17 35.05 15.13 30.03 11.19 35.73 33.67 34.36 22.31 10.86 16.99 75.55 -19.95 15.01 28.08 29.81 7.33 55.55 21.23 2.88 20.97 24.05 36.08 33.19 35.87 22.28 7.62 26.98 31.62 31.00 142 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 54 Preventing aircraft ground handling delays in Vietnam Airlines 30 40 50 76 51 45 88 30 40 40 55 35 40 38 51 25 85 63 50 55 80 65 50 27 68 60 75 50 45 40 45 52 55 74 30 96 70 50 25 50 90 15 75 73 15 20 20 43 35 35 28 15 10 15 27 18 20 15 20 18 48 25 22 20 40 20 25 18 35 20 15 20 15 17 19 16 15 14 16 65 58 38 27 15 60 10 15 38 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 53.46 61.43 25.35 77.01 13.52 74.10 19.28 47.80 32.01 32.89 32.36 49.20 69.58 54.60 -20.93 54.30 58.69 85.60 82.75 49.28 47.60 85.26 47.30 45.23 27.32 33.61 80.14 53.21 23.55 67.98 45.65 22.21 -16.65 61.61 25.96 20.74 76.32 41.00 103.11 35.69 73.65 47.54 52.23 85.70 28.57 34.43 7.91 45.89 -0.80 43.75 3.44 24.41 12.80 13.45 13.06 25.44 40.42 29.41 -26.13 29.19 32.42 52.21 50.11 25.50 24.27 51.95 24.04 22.52 9.35 13.98 48.19 28.39 6.58 39.25 22.83 5.60 -22.98 34.57 8.36 4.52 45.38 19.41 65.08 15.51 43.42 24.22 27.67 52.28 1 1 1 1 0 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 55 Preventing aircraft ground handling delays in Vietnam Airlines 135 72 30 30 25 50 55 105 20 80 65 30 25 47 45 18 20 80 32 55 30 30 75 140 75 50 30 100 57 56 40 45 80 43 50 84 43 35 97 30 15 55 35 40 94 40 23 15 22 25 33 60 16 39 45 20 18 20 23 18 19 44 18 15 16 23 40 85 40 35 19 43 30 14 15 20 39 15 25 50 20 17 60 23 10 15 10 25 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 82.04 95.72 63.73 42.18 60.15 23.27 59.89 82.31 63.13 73.69 52.29 46.63 50.47 37.49 56.94 42.76 56.22 51.92 27.91 48.57 30.22 87.39 59.38 46.21 7.97 55.86 56.48 56.64 93.51 18.47 24.45 59.09 44.21 95.12 32.02 70.08 -6.28 58.08 32.18 57.68 82.54 26.58 56.95 62.67 49.59 59.64 36.13 20.28 33.49 6.38 33.30 49.79 35.68 43.45 27.72 23.55 26.38 16.83 31.13 20.70 30.60 27.44 9.79 24.98 11.49 53.52 32.93 23.24 -4.88 30.34 30.80 30.91 58.02 2.84 7.24 32.71 21.78 59.20 12.81 40.80 -15.35 31.97 12.93 31.68 49.96 8.81 31.14 35.35 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 56 Preventing aircraft ground handling delays in Vietnam Airlines 50 68 25 20 25 20 20 15 60 80 75 50 55 30 120 35 40 60 58 20 35 20 15 15 10 15 10 20 40 44 26 15 15 60 10 28 25 30 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 -23.87 94.20 72.95 60.27 93.92 46.67 62.95 61.57 45.58 32.81 62.53 41.13 43.08 29.56 45.19 44.95 45.80 34.80 50.09 -28.29 58.53 42.91 33.58 58.32 23.58 35.55 34.54 22.78 13.39 35.24 19.50 20.94 11.00 22.49 22.32 22.94 14.86 26.10 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Table 5: 'Late cockpit crew' defect with mean = 50.58 and standard deviation = 23.82 As the study has shown that the cockpit crew activity are the critical path and an increase in their times can consequently increase the total turnaround time as well as delay time for flight. 57 Preventing aircraft ground handling delays in Vietnam Airlines Figure 16: Late cockpit crew defect Hence, the below suggestions based on analyzing the real data of ‘Late cockpit crew defect’ in figure 14 can reduce the mean and standard deviation.  Notify the cockpit crew at least two hours before the departure time.  Arrange the cockpit crew rotation clear and logical to make sure they have enough time for preparing their flights.  Remind the cockpit crew’s schedule and usually update the newest flight schedule if any change.  Prepare the sub-cockpit crew to avoid losing contact with assigned cockpit crew. 58 Preventing aircraft ground handling delays in Vietnam Airlines After applying these solutions to minimize the defect, researcher believes that mean and standard deviation could reduce to 20.5 and 8.3. Figure 17: Normal distribution for 'late cock pit crew' defects after applying solutions A set of 150 random numbers of T (late cockpit crew) are created and T (flight delay) are calculated by using the equation of multiple linear regressions T (flight delay) = {T (late cockpit crew) – 13.9} / 1.39 Researcher counts that there are 117 errors for this defect in Table 6. Thus, these above solutions are accepted and can apply to improve the punctuality of cockpit crew. 59 Preventing aircraft ground handling delays in Vietnam Airlines Trial values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 Mean = 20.5;sd = 8.3 16.60 14.64 24.15 7.44 28.42 16.38 13.72 18.20 29.85 37.67 20.39 25.26 17.35 19.25 32.40 15.15 21.41 15.33 19.43 38.97 30.18 20.73 14.22 14.55 25.93 6.78 10.86 33.31 13.50 24.87 23.24 21.02 29.06 31.18 12.19 23.48 21.18 16.44 21.48 21.55 32.89 20.02 22.98 T(flight delay 1.940889405 0.53071195 7.374726407 -4.648381848 10.44816816 1.785856409 -0.130952374 3.090037464 11.47567361 17.10417109 4.671021284 8.170672711 2.484023782 3.847425289 13.31123646 0.896709693 5.405139969 1.02984902 3.97954223 18.03848285 11.71560964 4.91224218 0.227611909 0.46492374 8.655672958 -5.124988404 -2.18617432 13.9636208 -0.286063728 7.89537282 6.71860198 5.123528769 10.90793825 12.43159909 -1.233304944 6.888517537 5.235201911 1.830518044 5.451298134 5.506128749 13.65907891 4.399487108 6.531112934 Error = 117 1 1 1 0 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 0 1 1 1 1 1 0 1 1 1 1 1 1 1 1 60 Preventing aircraft ground handling delays in Vietnam Airlines 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 29.80 17.79 11.88 24.45 17.05 25.69 13.31 4.50 11.92 21.88 29.45 15.39 21.38 20.43 7.54 0.36 21.95 8.05 39.51 32.32 26.27 12.17 19.24 21.84 14.50 27.73 18.19 16.77 17.24 23.23 5.35 11.44 24.21 36.53 24.64 16.09 31.43 18.56 9.11 14.58 12.08 29.37 16.94 31.04 11.43712549 2.801214338 -1.455107321 7.592823025 2.267549851 8.480291606 -0.42528764 -6.762274567 -1.426327429 5.742547393 11.1885712 1.069060228 5.381862915 4.698938582 -4.575279658 -9.743584027 5.789803366 -4.205182976 18.42312847 13.25049106 8.898763047 -1.246727498 3.844730582 5.713148688 0.433987051 9.949041349 3.086868038 2.065324473 2.40622191 6.714355292 -6.151136158 -1.767903037 7.416877742 16.27980225 7.727648069 1.573839876 12.60960495 3.35183363 -3.447116502 0.488722713 -1.311307296 11.12720507 2.189518169 12.32839764 1 1 0 1 1 1 0 0 0 1 1 1 1 1 0 0 1 0 1 1 1 0 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 0 1 0 1 1 1 61 Preventing aircraft ground handling delays in Vietnam Airlines 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 19.50 23.62 23.54 18.50 21.37 22.37 23.82 22.88 13.36 26.06 10.76 16.57 12.41 34.41 32.63 17.07 12.11 27.37 12.79 23.25 25.95 15.93 27.15 7.84 22.86 24.03 19.32 21.72 1.88 1.89 36.02 16.06 18.25 10.26 28.59 2.38 14.68 23.50 16.87 29.72 24.69 6.84 14.68 29.63 4.029123715 6.989209452 6.932768754 3.311330278 5.376973638 6.0911021 7.135066018 6.463989069 -0.387062137 8.746739128 -2.257649644 1.922654647 -1.06879484 14.75258281 13.47666727 2.281474968 -1.286926252 9.689312018 -0.801667976 6.727285741 8.672420685 1.460961102 9.530938423 -4.360589424 6.448730801 7.288044365 3.896819594 5.627581271 -8.648202624 -8.641578066 15.91134995 1.554112586 3.127970139 -2.617199159 10.5660557 -8.286639509 0.561850882 6.906793453 2.134225397 11.38210253 7.766179094 -5.079868522 0.559140201 11.31681993 1 1 1 1 1 1 1 1 0 1 0 1 0 1 1 1 0 1 0 1 1 1 1 0 1 1 1 1 0 0 1 1 1 0 1 0 1 1 1 1 1 0 1 1 62 Preventing aircraft ground handling delays in Vietnam Airlines 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 26.13 23.19 20.88 14.67 12.10 25.92 18.32 18.26 27.86 14.33 23.14 16.35 20.24 23.25 11.33 13.05 38.96 16.00 9.15 8.801473151 6.682095297 5.025156285 0.555271593 -1.292685409 8.648811713 3.179208753 3.135294353 10.04437294 0.309146942 6.644883897 1.760436514 4.564688303 6.729719398 -1.849167674 -0.611109631 18.0272033 1.512139951 -3.416977828 1 1 1 1 0 1 1 1 1 1 1 1 1 1 0 0 1 1 0 Table 6: 'Late cockpit crew' defect with mean = 20.5 and standard deviation = 8.3 4.1.2 ‘Refueling tanker positioning late’ defect Descriptive statistic of late cockpit crew Use the data of Appendix 1, the mean and standard deviation of T (late refueling tanker positioning) as computed as below: Mean = 33.3088 Standard deviation = 10.7859 Supplier management is vital for on-time performance and VINAPCO Company is a key supplier. If key supplier does not finish their processes on time, the resulting punctuality will drop significantly. For airlines, the refueling procedure cannot begin until the disembarking has ended, as well as boarding cannot start until refueling has finished due to safety regulation. In VNA, if flights have fire truck, the refueling procedure can start during 63 Preventing aircraft ground handling delays in Vietnam Airlines the disembarking and embarking activities. Hence, this process might not on the critical path because it can affect to on-time performance or not depending on anti-fire activity at TSN airport. However, VNA must pay $70 to TSN airport for each time operating anti-fire activity. Thus, a lot of money will be wasted and it can affect to punctuality performance if this defect occurs frequently. Mean shows that the time for this defect takes more than a half of hour. Standard deviation indicates that the data points tend to be close to the mean. This result is still not good for passengers as well as VNA Company. Multiple linear regressions For each data of T (late refueling tanker positioning), T (flight delay) is resulted in Appendix 1. Hence, researcher uses multiple linear regression to model the relationship between T (late refueling tanker positioning) and T (flight delay) by using data in Appendix 1. Standard Predictor Coefficients Error t Stat P-value T(late refueling tanker pos.) 11.87823577 1.782995268 6.661956 6.44E-09 T(flight delay) 1.070742078 0.082011538 13.05599 5.89E-20 S = 5.7413 R-Sq = 72.7% R-Sq(adj) = 72.1% Analysis of variance: Source DF SS MS F P 6E- Regression 1 5618.923753 5618.924 170.459 20 64 Preventing aircraft ground handling delays in Vietnam Airlines Residual Error 66 2175.590953 Total 67 7794.514706 32.9635 The regression equation is: T (late refueling tanker pos.) = 11.88 + 1.07 * T (flight delay) Reliability simulation and test mode For mean = 33.3088 and standard deviation = 10.7859 Figure 18: Normal distribution for 'late refueling tanker' defects before applying solutions 65 Preventing aircraft ground handling delays in Vietnam Airlines A set of 68 random numbers of T (late refueling tanker pos.) as well as 68 errors of this defect are created. By using above equation of multiple linear regressions T (flight delay) = {T (late refueling tanker pos.) – 11.88} / 1.07 Researcher computes the T (flight delay) and count error based on T (flight delay) again (positive = delay and negative = punctuality). Appendix 2 shows that, there are 64 errors after simulating and the result are accepted. Figure 19: Late refueling tanker truck positioning The below suggestions based on analyzing the real data of ‘Late refueling tanker truck positioning’ in figure 18 can reduce the mean and standard deviation.  Sign a service level agreement with VINAPCO Company, which address when to deliver it to increase the punctuality of refueling tanker truck. 66 Preventing aircraft ground handling delays in Vietnam Airlines  Continuous monitoring and feedback as well as incentives and penalties which close the feedback loop in the supplier relationship and which assign clear “consequence” to good or bad performance levels.  Focusing on maintaining refueling tanker truck periodically to make sure fueling activity has no problem. After applying these solutions to minimize the defect, researcher believes that mean and standard deviation could reduce to 10 and 5. Figure 20: Normal distribution for 'late refueling tanker' defects after applying solutions 67 Preventing aircraft ground handling delays in Vietnam Airlines A set of 68 random numbers of T (late refueling tanker pos.) are created and T (flight delay) are calculated by using the equation of multiple linear regressions T (flight delay) = {T (late refueling tanker pos.) – 11.88} / 1.07 Researcher counts that there are 35 errors for this defect (Appendix 3). Thus, these above solutions are accepted and can apply to improve the punctuality of refueling tanker activity. 4.1.3 ‘Late cabin crew’ defect Descriptive statistic of late cockpit crew Use the data of Appendix 4, the mean and standard deviation of T (late cabin crew) are computed as below: Mean = 40.0345 Standard deviation = 16.7677 For VNA’s flights, the cabin crew must arrives at the aircraft at least an hour before departure (one hour and a half for VIP flights). When the cabin crew members aboard the aircraft they shall immediately perform an emergency equipment check at their station, lavatories, overhead bins, cupboards and seat. After that, they are to make sure with VN/CX Company that all catering items, food, dry-goods, bars and duty-free are counted and on board and are stowed in their appropriate places before passengers arrive. Then they are to ensure that the cabin is safe for take-off. They will do security checks in cabin, galleys and lavatories, any suspicious. Thus, the more time cabin crew comes late to the aircraft, the more delay time flights are. Mean shows that the time for this defect takes more than a half of hour. Standard deviation indicates that the data points tend to be spread out a large range 68 Preventing aircraft ground handling delays in Vietnam Airlines of values. If this defect occurs, the time for cabin crew come late to aircraft could be large. Thus, flight could be delay more than one hour. Multiple linear regressions For each data of T (late cabin crew), T (flight delay) is resulted in Appendix 4 because the cabin crew activity belongs to critical path and any delay of this activity directly impacts the flight departure time. Thus, researcher uses multiple linear regression to model the relationship between T (late cockpit crew) and T (flight delay) by using data in Appendix 4. Standard Predictor Coefficients Error t Stat P-value T(late refueling tanker pos.) 12.99750195 1.816312807 7.155982 1.91E-09 T(flight delay) 1.028966461 0.060230728 17.08375 7.12E-24 S = 6.7875 R-Sq = 83.9% R-Sq(adj) = 83.61% Analysis of variance Source DF SS MS F P Regression 1 13445.96601 13445.97 291.8544 7E-24 Residual Error 56 2579.965027 46.0708 Total 57 16025.93103 The regression equation is: T (late cabin crew) = 12.99 + 1.03 * T (flight delay) Reliability simulation and test mode 69 Preventing aircraft ground handling delays in Vietnam Airlines For mean = 40.0345 and standard deviation = 16.7677 Figure 21: Normal distribution for 'late cabin crew' defects before applying solutions A set of 58 random numbers of T (late cabin crew) as well as 58 errors of this defect are created. By using above equation of multiple linear regressions T (flight delay) = {T (late cabin crew) – 12.99} / 1.03 Researcher compute the T (flight delay) and count errors based on T (flight delay) again (positive = delay and negative = punctuality). Appendix 5 shows that, there are 55 errors after simulating and the result are accepted. 70 Preventing aircraft ground handling delays in Vietnam Airlines Figure 22: Late cabin crew defect The below suggestions based on analyzing the real data of ‘Late cabin crew defect’ in figure 20 can reduce the mean and standard deviation.  Notify the cockpit crew at least two hour before the departure time.  Arrange the cockpit crew rotation clear and logical to make sure they have enough time for preparing their flights. After applying these solutions to minimize the defect, researcher believes that mean and standard deviation could reduce to 10 and 5. 71 Preventing aircraft ground handling delays in Vietnam Airlines Figure 23: Normal distribution for 'late cabin crew' defects after applying solutions A set of 58 random numbers of T (late refueling tanker pos.) are created and T (flight delay) are calculated by using the equation of multiple linear regressions T (flight delay) = {T (late cabin crew) – 12.99} / 1.03 Researcher counts that there are 15 errors for this defect (Appendix 6). Thus, these above solutions are accepted and can apply to improve the punctuality of cabin crew. 4.1.4 ‘Move aircraft from hangar to parking late” defect Descriptive statistic of moving aircraft from hangar to parking late Use the data of Appendix 7, the mean and standard deviation of T (move aircraft from hangar to parking late) are computed as below: 72 Preventing aircraft ground handling delays in Vietnam Airlines Mean = 29.8 Standard deviation = 12.5856 A ramp area at TSN airport is not large, it can keep a medium number of aircraft (around 40 aircrafts), but there’s not nearly enough space for the 60 to 80 aircraft in rush hours. When they need to maintenance, repair or are not in use, most of the aircraft are secured in the hangar. Thus, the more time aircraft come to parking, the more delay flight is. Multiple linear regressions For each data of T (move aircraft from hangar to parking late), T (flight delay) is resulted in Appendix 4. Hence, researcher uses multiple linear regression to model the relationship between T (late refueling tanker positioning) and T (flight delay) by using data in Appendix 7. PPredictor Coefficients Standard Error t Stat value T (late refueling tanker pos.) 4.8061 0.8407 5.72 0 T(flight delay) 1.00499 0.03371 29.81 0 S = 3.02487 R-Sq = 95.4% R-Sq(adj) = 95.3% Analysis of variance Source DF SS MS F P Regression 1 8130.5 8130.5 888.59 0 Residual Error 43 393.4 9.1 Total 44 8523.9 73 Preventing aircraft ground handling delays in Vietnam Airlines The regression equation is: T (move aircraft ...) = 4.81 + 1.00 * T (flight delay) Reliability simulation and test mode For mean = 29.8 and standard deviation = 12.5856 Figure 24: Normal distribution for 'late cabin crew' defects before applying solutions A set of 45 random numbers of T (late cabin crew) as well as 45 errors of this defect are created by using above equation of multiple linear regressions T (flight delay) = {T (move aircraft ...) – 4.81} / 1.00 74 Preventing aircraft ground handling delays in Vietnam Airlines Researcher computes the T (flight delay) and count errors based on T (flight delay) again (positive = delay and negative = punctuality). Appendix 8 shows that, there are 44 errors after simulating and the result are accepted. Figure 25: Late moving aircraft from hangar to parking The below suggestions based on analyzing the real data of ‘Late moving aircraft from hangar to parking’ in figure 23 can reduce the mean and standard deviation to 5 and 5.  TOC plans the ‘moving aircraft to hangar’ schedule and forward to VAECO Company as soon as possible.  Require Air Traffic Control to support VAECO in moving aircraft activity if there are many arrival or departure flights at that time.  Well-prepare equipment, employees and tools to prevent incidents and accidents during moving aircraft activity 75 Preventing aircraft ground handling delays in Vietnam Airlines  If any problem happens, employees who responsible for moving aircraft must contact directly to TOC to find out the solution. After applying these solutions to minimize the defect, researcher believes that mean and standard deviation could reduce to 5 and 5. Figure 26: Normal distribution for 'late cabin crew' defects after applying solutions A set of 45 random numbers of T (move aircraft ...) are created and T (flight delay) is calculated by using the equation of multiple linear regressions T (flight delay) = {T (move aircraft ...) – 4.81} / 1.00 76 Preventing aircraft ground handling delays in Vietnam Airlines Researcher counts that there are 28 errors for this defect (Appendix 9). Thus, these above solutions are accepted and can apply to improve the punctuality of moving aircraft from hangar to parking. 4.1.5 Calculate FTA After analyzing and minimizing above defects, researcher calculates FTA again based on data from table 3 with ‘Late cockpit crew’ = 117/426 = 0.2746, ‘Late cabin crew’ = 15/426 = 0.0352, ‘Late refueling tanker truck pos’ = 35/426 = 0.0822, ‘Move aircraft from hangar to parking late’ = 28/426 = 0.0657  P(Late catering removal) = 1 – (1 – P(Late catering truck pos)) * (1 – P(Late cabin crew)) * (1 – P(Late chock on)) * (1 – P(Move aircraft from hangar to parking late)) * (1 – P(Check CAT’s quality and quantities)) = 1 – (1 – 0.0258) * (1 – 0.0352) * (1 – 0.0117) * (1 – 0.0657) * (1 – 0.0141) = 0.1444  P(Late aircraft refueling) = 1 – (1 – P(Late refueling tanker pos)) * (1 – P(Late cockpit crew)) * (1 – P(Late chock on)) * (1 – P(Move aircraft from hangar to parking late)) * (1 – P(Incorrect fuel information) = 1 – (1 – 0.0822) * (1 – 0.2746) * (1 – 0.0117) * (1 – 0.0657) * (1 – 0.0423) = 0.4113  P(Late cabin cleaning) = 1 – (1 – (Late chock on)) * (1 – P(Move aircraft from hangar to parking late)) = 1 – (1 – 0.0117) * (1 – 0.0657) = 0.0767  P(Late passenger boarding) = 1 – (1 – P(Late catering removal)) * (1 – P(Late aircraft refueling)) * (1 – P(Late cabin cleaning)) = 1 – (1 – 0.1444) * (1 – 0.4113) * (1 – 0.0767) = 0.5349  P(Last minute passenger) = 1 – (1 – P(Late offload passengers)) * (1 – P(Late passenger boarding)) = 1 – (1 – 0.0399) * (1 – 0.6888) = 0.5535 77 Preventing aircraft ground handling delays in Vietnam Airlines  P(Late jet way removal) = 1 – (1 – P(Last minute CATs)) * (1 – P(Last minute passenger)) = 1 – (1 – 0.0305) * (1 – 0.5535) = 0.5671  P(Late conveyor removal) = 1 – (1 – P(Late luggage)) * (1 – P(Late offload passenger)) * (1 – P(Late conveyor positioning)) = 1 – (1 – 0.0376) * (1 – 0.0399’) * (1 – 0 ) = 0.076  P(Late lift-loader removal) = 1 – (1 – P(Late air cargo)) * (1 – P(Cut cargo)) = 1 – (1 – 0.0329) * (1 – 0.0094) = 0.0419  P(Late push-back) = 1 – (1 – P(Late jet way removal)) * (1 – P(Late lift-loader removal)) * (1 – P(Late conveyor removal)) = 1 – (1 – 0.076) * (1 – 0.5671) * (1 – 0.0419) = 0.6168  P(Punctuality flights) = 1 – P(Late push-back) = 1 – 0.6168 = 0.3832 P(on time) equals 38.32% indicates that the result is good after these defect are analyzed and simulated. Those above solutions will improve the aircraft ground handling performance as well as punctuality flights. 4.2 Ground Handling Cost Ground handling costs have an influence on the total DOC of the aircraft, which is not very big in comparison with aircraft price or depreciation, but it has its importance in overheads of the company. So, any improvement in the aircraft ground handling will reduce in the ground handling costs, since a cost reduction at one single ground handling process can be seen on the total ground handling costs. However, improving one single ground handling process might not lead to an overall improvement in turnaround time. Only by improving ground handling processes which are on the critical path, an improvement in the overall turnaround time can be achieved. 78 Preventing aircraft ground handling delays in Vietnam Airlines Since the study has reviewed in chapter 2, the DOC is sum of these cost elements: CDOC = CDEP + CINT + CINS + CF + CM + CC + CFEE These above defects {cabin crew (CC), cockpit crew (CC), refueling tanker truck (CF), moving aircraft from hangar (CM)} belong to the above formula. Thus, when these defects are controlled and decreased, researcher believes that the ground handling cost will be reduced. Chapter five - Research conclusion & Recommendation This chapter summarized all research result and come up some conclusions and as a result of finding and significant of study, researcher recommends some solution to solve the problem 5.1 Research conclusion The main objective of this study is examined the factors effect to aircraft ground handling activities that cause flights delay. The core objective of this study was established the solutions that control these factors. Based on data analysis, the factors that have influence strongly to flights delay in aircraft ground handling are cockpit crew, cabin crew, refueling tanker truck and moving aircraft from hangar to parking. The solutions that minimize theses factor’s defects are introduced and the study shows that these solutions will work. Time is money. VNA is aware of this well-known fact. Time is a critical value especially on the ground during handling procedure. This period does not allow an airline to generate any revenues; revenues can be achieved only when the aircraft is in the air. Therefore is avoiding the wasted time in aircraft ground handling one of the biggest challenges which VNA are facing in theses day when the market is oversaturated with 79 Preventing aircraft ground handling delays in Vietnam Airlines Vietjet, Jetstar and AirMekong. Moreover, improving punctuality on the ground means possibility of adding additional frequency for an aircraft flying on short or medium-haul routes. From marketing point of view, more frequencies mean more attractive schedule and competitive advantage. From economic point of view, more frequencies mean more passengers and more revenues. 5.2 Recommendation Since the turnaround process is a complex process where several equipment and staff are in constant interaction, a simulation can be very useful to estimate the performance of the process taking into account interactions and allowing exploring new solutions. 5.3 Limitation Like all research, this research has several limitations to the interpretation of the result. Firstly, the limitation relates to the data. The solutions were given and tested by using Monte Carlo method. Then the solutions will be more accuracy and convince if it is applied to aircraft ground handling in reality. Secondly, DOC should be more focused on this study. Since the amount of data about DOC is not enough, therefore researcher gave a conclusion about DOC based on DOC’s equation that reviewed in literature review. Hence the results that DOC might be proved clearly by implementing more real data of the DOC. 80 Preventing aircraft ground handling delays in Vietnam Airlines References http://vietbao.vn/kinh-te/vietnam-airlines-gia-nhap-IATA/40176660/87/ Datamonitor. 2009. Global Airport Services, Industry profile. May, 1-16 Gomez, F. &Scholz, D.2009. Improvements to ground handling operations and their benefits to direct operating costs. Hamburg: Hamburg University of Applied Sciences, 1-3 Martinez-val, R. Perez, E.; Cuerno, C.: Calculo de Aviones. Guiones Y Figuras Scholz, Dieter: EWADE – A student project of a blended wing body. Hamburg University of Applied Science, Aircraft Design and Systems Group (Aero), 2007 Bisignani, G. 2009. International Air Transport Association Annual Report. IATA Publication, 24 June, 10-52 Durr, A.2008. Deregulation of ground handling services at airports. Berlin: HumboldtUniversitatzu Berlin, 1-5 Anna Norin, 2008. Airport Logistics – Modeling and Optimizing the Turn-Around Process, 85-90 Willis, J. 2009b. I.A.H.A International Aviation Handler Association. Paper presented at the 11th annual Ground Handlers International Conference, Naples, 18 November, 1-12 Van de Voorde, E.2010. A view of the ground handling industry from the outside. How does it look like? A paper presented at the 12th annual Ground Handling International Conference, Vienna, 29 November, 29. 81 Preventing aircraft ground handling delays in Vietnam Airlines White, B., 2005. Dissertation skills. London: Thomson Learning. Saunders, M., Lewis, P. &Thornhil, A., 2007. Research methods for business students. Harlow: Prentice hall. Saunders, M., Lewis, P. &Thrornhill, A., 2009. Research methods for business studentd. fifth ed. Harlow: Prentice Hall. Walpole, R.E., & Myers, R.H. (1989). Probability and statistics for engineers and scientists(4th ed.). New York: Macmillan Publishing Company. Zaremba, S.K. (1968). The mathematical basis of Monte Carlo and quasi-Monte Carlo methods. SIAM Review 10(3), pp. 303-314. Mann, N.R., Schafer, R.E., &Singpurwalla, N.D. (1974) Methods for statistical analysis of reliability and life data. New York: John Wiley & Sons. Kelley, James. Critical Path Planning and Scheduling: Mathematical Basis. Operations Research, Vol. 9, No. 3, May–June, 1961. 82 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 1 T(refuelingtanker pos late) 30 43 30 35 60 50 40 20 20 30 30 35 30 30 35 30 30 25 30 25 25 30 35 35 20 30 25 25 30 30 25 40 50 60 T(flight delay) 15 15 15 20 50 40 30 13 10 15 25 25 15 20 25 25 20 15 20 15 15 20 25 25 15 20 15 18 20 18 15 23 30 27 T(refueling tanker pos late) 30 30 25 28 30 60 30 30 15 30 30 35 30 55 45 30 35 59 40 30 20 35 50 60 35 25 15 20 25 40 30 25 35 35 T(flight delay) 15 15 10 15 15 40 15 10 9 18 15 23 10 44 19 18 15 39 23 15 15 16 30 35 15 19 9 10 15 30 18 17 20 15 83 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 2 T(Refueling tanker pos late) 30 43 30 35 60 50 40 20 20 30 30 35 30 30 35 30 30 25 30 25 25 30 35 35 20 30 25 25 30 30 25 40 50 60 30 30 25 T(Flight delays) 15 15 15 20 50 40 30 13 10 15 25 25 15 20 25 25 20 15 20 15 15 20 25 25 15 20 15 18 20 18 15 23 30 27 15 15 10 Error = 68 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Trial values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 mean = 33.3088; sd = 10.7859 51,18 29,66 43,44 29,13 48,25 29,27 54,80 29,03 38,86 28,02 36,35 26,28 51,14 21,78 23,59 36,84 32,64 47,39 53,79 42,18 18,37 18,60 66,89 33,24 15,94 10,45 25,61 10,79 31,33 26,01 11,50 5,83 70,93 29,05 50,40 26,23 30,89 T(Flight delays) 36,70 16,61 29,47 16,11 33,97 16,24 40,09 16,02 25,20 15,07 22,86 13,45 36,67 9,25 10,94 23,31 19,39 33,16 39,14 28,30 6,07 6,28 51,38 19,95 3,79 -1,34 12,83 -1,01 18,17 13,20 -0,35 -5,65 55,15 16,03 35,98 13,40 17,76 Error = 64 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 0 0 1 1 1 1 1 84 Preventing aircraft ground handling delays in Vietnam Airlines 28 30 60 30 30 15 30 30 35 30 55 45 30 35 59 40 30 20 35 50 60 35 25 15 20 25 40 30 25 35 35 15 15 40 15 10 9 18 15 23 10 44 19 18 15 39 23 15 15 16 30 35 15 19 9 10 15 30 18 17 20 15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 35,54 17,80 30,26 26,93 37,83 32,72 22,12 33,14 31,08 16,10 51,24 45,42 32,07 28,65 20,13 17,01 22,98 49,13 35,27 32,31 24,45 40,24 4,54 46,71 47,37 46,42 39,79 54,38 19,72 29,30 41,82 22,10 5,53 17,17 14,06 24,24 19,46 9,57 19,86 17,93 3,95 36,76 31,33 18,86 15,67 7,71 4,80 10,37 34,79 21,84 19,08 11,74 26,48 -6,86 32,53 33,15 32,26 26,07 39,69 7,32 16,27 27,96 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 85 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 3 Trial values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 m=10;sd=5 10.64 10.16 6.25 15.60 -0.91 9.54 2.97 16.30 10.30 9.31 18.45 13.47 8.65 6.69 13.02 7.58 17.40 9.43 12.92 13.32 11.24 14.04 21.34 7.08 12.14 14.11 12.98 8.46 11.80 15.61 11.64 12.02 5.52 12.25 8.93 4.12 17.37 9.28 T(Flight delays) -1.153330406 -1.604101776 -5.252327865 3.476285506 -11.94763316 -2.180184732 -8.315400957 4.1268741 -1.470815342 -2.398674589 6.142153318 1.483154991 -3.016886187 -4.844133209 1.070042331 -4.015862384 5.158836648 -2.289359463 0.97263932 1.348314029 -0.594461659 2.014565249 8.835648257 -4.480530501 0.24443643 2.082957918 1.032207352 -3.192646628 -0.06998843 3.480614194 -0.219449735 0.133039965 -5.942338475 0.351225428 -2.756268823 -7.24107699 5.131747303 -2.429272475 Error = 35 0 0 0 1 0 0 0 1 0 0 1 1 0 0 1 0 1 0 1 1 0 1 1 0 1 1 1 0 1 1 0 1 0 1 0 0 1 0 86 Preventing aircraft ground handling delays in Vietnam Airlines 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 1.79 17.55 13.73 7.10 1.57 18.06 19.12 3.83 14.38 11.93 12.21 15.06 19.78 16.41 16.64 7.81 4.10 14.39 4.40 10.11 4.27 3.42 11.08 17.57 17.22 15.00 16.50 10.29 8.50 13.44 -9.418605767 5.294774911 1.731379344 -4.46277383 -9.624459374 5.774663855 6.759430894 -7.517542466 2.339059875 0.051214777 0.312118934 2.975725162 7.375138604 4.23159529 4.450057575 -3.800747283 -7.26787779 2.346342938 -6.984636541 -1.651038793 -7.109778738 -7.894904958 -0.743463515 5.319515964 4.990090238 2.911805618 4.320237026 -1.478734125 -3.151244509 1.461730585 0 1 1 0 0 1 1 0 1 1 1 1 1 1 1 0 0 1 0 0 0 0 0 1 1 1 1 0 0 1 87 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 4 T(Late cabin crew) 15 30 25 20 35 50 45 35 70 60 60 45 30 30 35 30 30 25 30 30 60 25 58 30 40 50 40 90 40 T(Flight delays) 10 18 20 15 15 45 38 15 44 50 49 35 15 15 30 20 15 15 15 17 50 10 45 13 25 19 15 70 18 T(Late cabin crew) 90 60 20 35 28 45 30 23 30 50 35 60 20 15 30 40 40 30 28 20 35 50 45 35 70 60 60 45 30 T(Flight delays) 67 35 15 17 20 30 20 15 15 29 15 37 15 10 17 18 30 17 20 15 15 45 38 15 44 50 49 35 15 88 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 5 T(Late cabin crew) 15 30 25 20 35 50 45 35 70 60 60 45 30 30 35 30 30 25 30 30 60 25 58 30 40 50 40 90 40 90 60 20 35 28 45 30 23 30 T(Flight delays) 10 18 20 15 15 45 38 15 44 50 49 35 15 15 30 20 15 15 15 17 50 10 45 13 25 19 15 70 18 67 35 15 17 20 30 20 15 15 Error = 58 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Trial values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 40.03;17,77 27,09 44,82 44,97 27,96 39,34 4,46 35,04 36,68 14,51 50,93 39,29 -4,87 53,74 31,18 29,45 25,59 24,52 36,96 20,37 8,28 26,57 25,18 15,19 56,07 24,19 37,07 61,34 33,82 66,13 35,97 36,77 57,52 37,39 45,50 67,15 24,97 29,50 13,91 T(Flight delays) 13,69565159 30,92435949 31,07557988 14,54222408 25,60150259 -8,29569876 21,4173758 23,01585254 1,472259597 36,86064238 25,55403335 -17,3618203 39,59554257 17,66702404 15,98583903 12,24217559 11,20237169 23,29223788 7,161069566 -4,58585342 13,19264904 11,84078809 2,133815488 41,86417201 10,8773188 23,39453246 46,98073567 20,24118022 51,63838271 22,32465514 23,09993026 43,26971303 23,70618592 31,59040536 52,62529801 11,63154229 16,04026816 0,88421126 Error = 55 1 1 1 1 1 0 1 1 1 1 1 0 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 89 Preventing aircraft ground handling delays in Vietnam Airlines 50 35 60 20 15 30 40 40 30 28 20 35 50 45 35 70 60 60 45 30 29 15 37 15 10 17 18 30 17 20 15 15 45 38 15 44 50 49 35 15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 42,52 52,19 30,09 62,20 33,67 19,65 60,95 53,88 51,08 51,45 45,79 40,26 42,06 21,10 65,18 22,58 52,63 41,91 43,34 53,73 28,69436315 38,08516328 16,61101706 47,81354257 20,0938697 6,468350503 46,60279812 39,73589069 37,00977646 37,37256357 31,87073637 26,4956796 28,24800878 7,877935336 50,70920487 9,316980709 38,51614302 28,10178609 29,48561508 39,58158392 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 90 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 6 Trial values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 m=10, sd=5 14,45 7,96 11,54 9,66 9,74 16,02 9,52 16,59 14,65 13,02 1,86 4,14 7,68 4,18 16,44 9,90 9,58 8,20 4,42 6,74 17,42 3,98 12,27 11,30 -0,04 9,14 18,75 12,54 7,44 4,88 3,73 10,99 9,27 10,55 13,96 11,84 7,59 17,82 T(Flight delays) 1,410929669 -4,892148734 -1,41756172 -3,246388905 -3,165784362 2,937057159 -3,384336437 3,488489857 1,601961275 0,02640998 -10,82622619 -8,60375992 -5,16481229 -8,565952656 3,341742935 -3,006548498 -3,325990406 -4,660327987 -8,335764321 -6,078045598 4,297908752 -8,760518214 -0,703448382 -1,64861193 -12,66726312 -3,748639211 5,589418998 -0,446751376 -5,396302477 -7,893188038 -9,002241298 -1,952976468 -3,62424009 -2,376595551 0,931197956 -1,125277249 -5,252899293 4,688157864 Error = 15 1 0 0 0 0 1 0 1 1 1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 1 91 Preventing aircraft ground handling delays in Vietnam Airlines 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 10,62 14,57 7,80 9,68 11,50 16,48 12,52 16,85 6,90 2,99 9,04 13,82 12,33 10,59 11,48 8,70 4,77 0,09 20,51 12,23 -2,305773071 1,52837948 -5,048449824 -3,228467129 -1,451517949 3,383003952 -0,460576234 3,742152757 -5,92762428 -9,72746117 -3,849170194 0,796533735 -0,648792549 -2,338212072 -1,471718169 -4,174555971 -7,997839455 -12,54432699 7,302771594 -0,745670887 0 1 0 0 0 1 0 1 0 0 0 1 0 0 0 0 0 0 1 0 92 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 7 T(Move a/c from hangar to parking late) 20 33 27 35 22 17 17 18 25 15 65 22 22 20 15 20 22 35 40 95 22 25 T(Flight delays) 18 30 24 20 17 15 15 15 22 10 60 20 20 15 10 15 20 30 35 88 15 20 T(Move a/c from hangar to parking late) 35 30 20 30 35 37 22 17 19 24 26 20 28 23 22 15 10 16 22 18 25 22 20 T(Flight delays) 33 15 15 18 30 30 19 15 13 20 22 17 25 20 18 10 5 12 18 14 17 15 12 93 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 8 T(move a/c from hangar 20 33 27 35 22 17 17 18 25 15 65 22 22 20 15 20 22 35 40 95 22 25 35 30 20 30 35 37 22 17 19 24 26 20 28 23 22 T(flight delay) 18 30 24 20 17 15 15 15 22 10 60 20 20 15 10 15 20 30 35 88 15 20 33 15 15 18 30 30 19 15 13 20 22 17 25 20 18 Error = 45 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Trial values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 29.8 ; 12.5856 24.68 15.64 30.06 30.50 14.66 14.88 32.85 23.22 5.33 13.24 31.13 18.68 32.80 14.57 30.81 6.27 65.08 29.22 11.42 34.14 12.48 31.50 13.91 -0.61 25.94 18.73 23.80 31.61 27.75 33.54 35.10 19.52 22.56 20.13 28.58 49.93 29.20 T(flight delay) 19.87 10.83 25.25 25.69 9.85 10.07 28.04 18.41 0.52 8.43 26.32 13.87 27.99 9.76 26.00 1.46 60.27 24.41 6.61 29.33 7.67 26.69 9.10 -5.42 21.13 13.92 18.99 26.80 22.94 28.73 30.29 14.71 17.75 15.32 23.77 45.12 24.39 Error = 44 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 94 Preventing aircraft ground handling delays in Vietnam Airlines 15 10 16 22 18 25 22 20 10 5 12 18 14 17 15 12 1 1 1 1 1 1 1 1 38 39 40 41 42 43 44 45 17.26 14.61 51.35 22.16 41.78 57.01 30.07 28.54 12.45 9.80 46.54 17.35 36.97 52.20 25.26 23.73 1 1 1 1 1 1 1 1 95 Preventing aircraft ground handling delays in Vietnam Airlines Appendix 9 Trial values 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 5;5 12.53 16.47 2.21 14.32 3.03 5.28 3.97 -6.97 4.98 4.83 0.22 16.76 6.30 0.25 12.53 -3.92 8.00 6.24 1.79 14.62 10.49 0.21 5.90 0.21 4.90 6.73 -9.06 0.38 4.39 15.14 3.61 5.86 4.95 -0.32 6.96 9.86 6.44 T(flight delay) 7.72 11.66 -2.60 9.51 -1.78 0.47 -0.84 -11.78 0.17 0.02 -4.59 11.95 1.49 -4.56 7.72 -8.73 3.19 1.43 -3.02 9.81 5.68 -4.60 1.09 -4.60 0.09 1.92 -13.87 -4.43 -0.42 10.33 -1.20 1.05 0.14 -5.13 2.15 5.05 1.63 Error = 28 1 1 0 1 0 1 0 0 1 1 0 1 1 0 1 0 1 1 0 1 1 0 1 0 1 1 0 0 0 1 0 1 1 0 1 1 1 96 Preventing aircraft ground handling delays in Vietnam Airlines 38 39 40 41 42 43 44 45 1.34 6.80 11.79 5.49 8.26 6.91 12.57 -1.12 -3.47 1.99 6.98 0.68 3.45 2.10 7.76 -5.93 0 1 1 1 1 1 1 0 97 [...]... When aircraft turnaround is finished and aircraft is ready to leave according to schedule, aircraft pilot contacts ATC and waits for the clearance to begin push-back procedure Figure 2 below illustrates the conceptual model of the system 19 Preventing aircraft ground handling delays in Vietnam Airlines Figure 2: Conceptual model of the aircraft ground handling system 20 Preventing aircraft ground handling. .. work together effectively to deliver the optimal turnaround This is further complicated when the aircraft is being handled at a remote airport by third party ground handling organizations 16 Preventing aircraft ground handling delays in Vietnam Airlines 2.2 Aircraft Ground Handling in VNA at TSN Airport Ground handling help to address service requirements of an airliner between the time it arrives at a... delayed flights in 2011due to aircraft ground handling (annual report’s TOC), VNA operation is not very effectively in aircraft ground handling The project is about aircraft ground handling process in VNA Aircraft ground handling is a key component of the air transport logistics supply chain as it facilitates the mobility of cargo and people from one destination to another Delays in movement of cargo... revealed the background to aircraft ground handling, ground handling cost, the modeling of the aircraft turnaround process, ideas to improve ground handling operations, methods for reduction in mean turnaround times and human factors in aircraft ground handling Review of literature on the concept of the system show that the main issue is to be on time in terms of minimum turnaround times, but ground handlers... essential 2.5 Ideas to improve ground handling operations According to Gomez, F &Scholz, D (2009), Speed, efficiency and accuracy are important in ground handling operations in order to minimize turnaround time and ground handling costs Improvement to ground handling operation always aim at reducing turnaround time and ground handling costs, if improvements to ground handling operations also reduce... airport is aircraft ground handling, usually by causing mistakes or wrong activities 14 Preventing aircraft ground handling delays in Vietnam Airlines Within this research, it is focused on ground handling services analyzing to prevent the flight delays 1.3 Research objectives The objectives of the research project are to:  To identify factors that cause delay in aircraft ground handling  To evaluate... main issue is to be on time in terms of minimum turnaround times, but ground handlers in 30 Preventing aircraft ground handling delays in Vietnam Airlines VNA usually have wrong activities and mistakes Aircraft modifications or new ground equipment may improve aircraft ground handling in advance However, the ground handling costs are a tough question for VNA due to the fact that capital, human resources... the cabin 25 Preventing aircraft ground handling delays in Vietnam Airlines Figure 6: Critical path 737-800 This research used GDR (Group Decision Room) brainstorm session as basic for developing suggestions and possible solutions to improve the turnaround ground handling processes Table 1: Turnaround ground handling process design specifications for a new narrow body turnaround ground handling concept... all aircraft ground handling operations, look for the critical factors that effect on flight delay and find out the final effect in flight delay if those factors are controlled This report further describes the methodology of how to structure the project, and a project plan with a time schedule is given Keywords: delay, aircraft ground handling, punctuality 12 Preventing aircraft ground handling delays. .. o’clock flight to Da Nang 18 Preventing aircraft ground handling delays in Vietnam Airlines which is promised in the airline’s published schedule Hence, controlling wrong activities in aircraft ground handling also control flight delay, minimize operating costs and build trust in passengers The aim of this study is to identify and investigate ideas to improve aircraft ground handling and control flight ... defense fields 43 Preventing aircraft ground handling delays in Vietnam Airlines Figure 13: Fault tree model for aircraft ground handling 44 Preventing aircraft ground handling delays in Vietnam... when the aircraft is being handled at a remote airport by third party ground handling organizations 16 Preventing aircraft ground handling delays in Vietnam Airlines 2.2 Aircraft Ground Handling. .. to aircraft ground handling (annual report’s TOC), VNA operation is not very effectively in aircraft ground handling The project is about aircraft ground handling process in VNA Aircraft ground