Indicadores, control y direccionamiento estratégico

This section discusses delays in the airline industry. For this section, we use airline specific literature and information sources. For all influences that contribute to delay, The International Air Transport Association (IATA) designed a code set that indicates what kind of delay a flight is experiencing; EUROCONTROL makes an annual report for these kinds of delay. We summarize the causes for aircraft delay in Table 14.

Xu et al. (2008) give a visualization of delay generation and absorption at airports and during flights in Figure 19.

40 Figure 19: Delay generation and absorption, derived from Xu et al. (2008)

Important factors regarding the Refueling department are the AIBT (Gate-in time in Figure 19), the published departure time, the disturbances on the airport that affect the fueling process, and process time and disturbances in the refueling process itself. The IATA delay codes in combination with Figure 19 give information about these factors. The most important code in this research is code 36: Flight delay induced by fueling operations.

 The AIBT could depend on all factors that affect the aircraft prior to this moment. This could either be a:

o Reactionary delay as a result from an earlier flight. o Problems at the airport of departure.

o Problems en route.

o Problems at the airport of arrival (Schiphol).  The process duration could depend on:

o Disturbances during driving. o Disturbances around the aircraft. o Equipment disturbances.

o Fuel task type. o Used equipment. o Destination.

o Departure weather. o En route weather.

 The published departure time could depend on: o Late arrival of the inbound flight.

41 Table 14: Delay types, derived from (EUROCONTROL, 2013)

Type of Delay Description plus IATA delay codes Examples

Airline Passenger and Baggage 11‐19 Problems with check-in and boarding of the aircraft, lateness of passengers.

Cargo and Mail 21‐29 Problems with documentation and

lateness of cargo.

Aircraft and Ramp Handling 31‐39 AS is mostly included here. Problems with equipment, lack of staff, aircraft documentation, and loading problems with cargo. Code 36 denotes delays due to fueling.

Technical and Aircraft Equipment 41‐49 Defects, non-scheduled maintenance, late release from scheduled- maintenance

Damage to Aircraft & EDP/Automated Equipment Failure 51‐58 Damage to aircraft and/or technical problems with automated systems. Flight Operations and Crewing 61‐69 Late crew boarding, crew shortage, and

late completion or change of flight documentation.

Other Airline Related Causes Others

Airport ATFM due to Restriction at Destination Airport 83

Airport Facilities 87

Restrictions at Airport of Destination 88 Closed runway, industrial action, staff shortage, political unrest, noise abatement, night curfew etc.

Restrictions at Airport of Departure 89 Closed due to weather (ATFM only), industrial action, staff shortage, political unrest, etc.

En-Route ATFM due to ATC En‐Route Demand / Capacity 81 Capacity problems

ATFM due to ATC Staff / Equipment En‐Route 82

Governmental Governmental Security and Immigration 85‐86

Weather Weather (other than ATFM) 71‐79 Weather conditions at departure, arrival airport, or during flight. De-icing. airport snow, ice, or sand removal.

ATFM due to Weather at Destination 84

Miscellaneous

Reactionary Late arrival of aircraft, crew, passengers, or load from earlier flights 91-96

Awaiting passengers, crew, or aircraft for next flight. Rerouting, diversion, or aircraft change.

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40-50 % of flight delays is caused by the reduction of capacity in the flight system, the remaining percentage is due to airline operations, of which 20 to 30 % is reactionary, and 10% comes forth from technical failures. (Wu, 2008)

The United States Federal Aviation Administration (FAA) records information about flight delay. For the period June 2003 to April 2014, 77.89% of U.S. flights were on time. Delays (aircraft arriving at least 15 minutes later than scheduled) are either attributed to system delay (less capacity than demand in the flight system), aircraft arriving late (reactionary), and air carrier (airline operations) delay (The Federal Aviation Authority (2014)). Figure 21 splits out the factors that result in system delay. Weather is the main cause for delay in the system. Then a flight volume that is higher than the system capacity is the second reason for delay. Limitations in runway availability come in third.

Also for the European flights, there are statistics. Ranked from high to low, the main causes for delay are Reactionary, Airline, Air Traffic Flow Capacity Management (ATFCM) airport, weather not related to ATFCM, ATFCM en-route, Government, problems at airport not related to ATFCM, and ATFCM due to weather. (EUROCONTROL, 2013)

ATFCM related delays are all due to a reduction of capacity for air traffic, e.g., a reduction in runway capacity is an ATFCM airport delay, and a reduction in security check capacity is an airport delay not related to ATFCM.

For scheduling reasons, it is important to know whether aircraft arrive on time, and how the deviation from the expected arrival time is distributed. EUROCONTROL (2013) describes a distribution of arrival punctuality over 2012 and 2013 for European airlines (see Figure 22). Harmsen (2012) described such a distribution for an arbitrary month of KLM operations and different type of aircraft, such that he could simulate the impact of arrival delay on the performance of Refueling.

Costs of delayed aircraft are essential to ground services of each airliner. If the cost of scheduling more personnel does not outweigh the incurred cost of delayed aircraft, scheduling extra personnel results in unwanted over capacity. Extensive studies by Cook and Tanner (2011) for EUROCONTROL show delay costs for airliners during all phases of flight for several aircraft type. Their study describes fuel, maintenance, fleet, crew, and passenger costs in relation to aircraft delay, and delay effects that propagate through the airliner’s flight network. Small delays have little effect on the passengers and often do not result in propagated delays throughout the flight network. Increasing delay times, however, result in non-linear higher costs to the airliner. Cook and Tanner (2011) described a low-cost, base, and high- Figure 20: Distribution of arrival delays U.S. June 2013 - April 2014

(derived from The Federal Aviation Authority (2014))

Figure 21: Factors causing national aviation system delays, June 2003 - April 2014 (derived from The Federal Aviation Authority (2014))

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cost scenario. The base scenario in Figure 23 shows incurred costs for an airliner that has a delayed aircraft standing on the ground.

Figure 22: Average aircraft delay in the European region, in fraction of arrivals, derived from EUROCONTROL (2013)

Harmsen (2012) estimated the shift cost around 238 euros. For the base scenario, any 15-minute delay coming) is already more expensive than the average personnel costs of a one person shift. AS, however, can only justify an extra shift when they expect the current schedule to result in a delay induced by one of its services.

Figure 23: At gate delay costs for different aircraft type in euros, derived from Cook and Tanner (2011)