Impact of Airline Crew Scheduling on Delays and Cancellations of Commercial Flights
GAO-08-1041R: Published: Sep 17, 2008. Publicly Released: Sep 17, 2008.
Media coverage of airline service problems, combined with congressional hearings on these problems, has put flight delays and cancellations in the spotlight. Department of Transportation (DOT) data show that flight delays and cancellations have generally increased over the last decade. Since 1998, the number of flight delays and cancellations has increased 62 percent nationwide, while the number of scheduled flight operations has increased about 38 percent. Also, a May 2008 report by the Joint Economic Committee found that, collectively, passengers were delayed 320 million hours in 2007. The report also estimated that domestic flight delays last year cost the U.S. economy as much as $41 billion and raised airlines' operating costs by $19 billion. In 2007, airlines reported to DOT that 73 percent of flights were on time, while 24 percent were delayed and 2 percent were canceled. Of those flights that were delayed, airlines reported the majority of flight delays were caused by 3 categories of delays: a previous aircraft arriving late; the national aviation system--a category of delays that encompasses a broad set of circumstances, such as congestion or bad weather; and air carrier--a category of 42 potential causes of delay that includes, but is not limited to, problems associated with how the airline schedules its flight crews. With demand pushing more flights into an already congested airspace, one delayed or canceled flight can create ripples in the system, causing other flights to be delayed or canceled. In such an environment, the effective scheduling of available flight crews is key to better ensuring the on-time performance of flights. Congress asked that we assess commercial airline policies and practices for crew scheduling. Accordingly, this report addresses the following questions: (1) How do airlines schedule flight crews? (2) To what extent, if any, does crew scheduling contribute to flight delays and cancellations? (3) What steps do stakeholders report might reduce delays and cancellations due to crew scheduling?
Airlines use computerized optimization models to schedule flight crews while adhering to federal regulations and contractual agreements. As a fundamental safety tenet, all airlines are subject to Federal Aviation Regulations that establish maximum crew flight times and minimum rest requirements. In addition, airlines must adhere to conditions in their collective bargaining agreements, which they negotiate with the labor organizations representing their employees. Labor is generally one of an airline's largest costs, along with fuel. Consequently, airlines use computerized models to schedule crews in a manner that helps to minimize these costs, while adhering to the Federal Aviation Regulation limitations and to collective bargaining agreement conditions. Flight delays and cancellations caused by crew scheduling alone appear to be rare and frequently arise from other problems. Detailed data provided by 6 of the airlines indicated that, in 2007, delays due to crew scheduling accounted for no more than about 3 percent of any airline's flights, and that cancellations due to crew scheduling were less than one-quarter of 1 percent of all flights for any airline. Most other stakeholders similarly indicated that crew scheduling is not a major contributor to delays and cancellations. Airlines and other stakeholders identified other problems as being more significant causes of flight delays and cancellations, including aircraft maintenance and problems with the national airspace system, such as congestion or bad weather. Additionally, airlines reported that delays and cancellations due to crew scheduling are often the result of other delays, which can create a "ripple effect" when crews and aircraft needed for subsequent flights are not available on time. Stakeholders identified several ongoing and potential actions that airlines and the government could take to reduce delays and cancellations attributable to crew scheduling. Airlines have taken several steps to reduce the potential for delays and cancellations due to crew scheduling, including adding time to flight schedules to account for delays, using reserve crews, positioning crews in anticipation of expected weather, and scheduling crews to stay with the same aircraft between flights. Additionally, several of the airlines reported taking steps to avoid delays in the New York area--a region known for airspace congestion--such as not scheduling crews on often-delayed flights scheduled to leave New York at later times in the day, and avoiding scheduling connecting flights out of New York to an airline's hub airport. Stakeholders also suggested a number of steps that the federal government could take, including modernizing the air traffic control system; improving East Coast operations, particularly in the New York region; and revising the Federal Aviation Regulations pertaining to duty and rest hours. Finally, in July 2008, the federal government began a test program designed to evaluate expedited access to secure areas of airports for properly credentialed commercial flight crew members, which could reduce the time that flight crew members spend in security screening lines.