Publications

Reduction of air carrier flight delay in the U.S. National Airspace System (NAS) has been a major objective of the Federal Aviation Administration (FAA) for many years. Much of the current delay arises from weather-induced delays at airports. When a plane is delayed on one of the day's flights, there can be a carryover delay that affects later flights by that aircraft. In this report, we develop statistical models to predict: 1. The "downstream" delays that occur when a flight experiences an initial delay, and 2. The likelihood of flight cancellation as a function of the initial delay. Using historical airline-reported delays for December 1993, we conclude that the mean "downstream" delay is approximately 80 percent of the initial delay, i.e., the net delay for an aircraft due to an initial flight delay is approximately 1.8 x the initial delay.

This report reviews the benefits that the CTAS component of the FAA Terminal Air Traffic Control Automation program (TATCA) offers to aviation users. In particular, the report evaluates the prospects that exist for increasing arrival capacity during Instrument Meteorological Conditions (IMC) by introducing CTAS functionality into current operations. The impact of anticipated capacity gains on air traffic delays is analyzed. Savings in delay are translated into dollar savings using FAA statistics on the fleet-weighted direct cost of delay to domestic air carriers. Also, the value of passenger time is considered. Economic impacts are estimated and reported on an annualized, nationwide basis. Adopting FAA projections of future traffic growth, estimates of delay and attendant cost savings to air carriers and their passengers are provided for fiscal years 1995-2015. Taking the nominal estimate of a 12% gain in IMC arrival capacity, a nationwide implementation of CTAS would be estimated to save an average of 412,000 hours of air carrier delay annually over this 21-year period, and 273 million gallons of fuel per year. With current fuel and labor costs, this amounts to average direct operating savings to air carriers of $1.5 billion per year, and value to passengers of over $3 billion per year, in constant 1988 dollars. There may be factors outside the scope of this study that restrict the implementation of CTAS to certain sites, or that limit the weather conditions in which CTAS is effective. Methods are discussed in the report for modifying benefits estimates in response to such considerations. However, since development and implementation costs of CTAS are estimated to be a small fraction of the benefits enumerated above, and since the delay savings recur annually, it is concluded that the development of STC automation software such as CTAS is economically justifiable.

Terminal Air Traffic Control Automation (TATCA) is an FAA research and development program to provide computer-aided sequencing, spacing, and management of air traffic flows in terminal areas. This paper discusses technical and national economic benefits that are attainable with such a terminal automation program.