Prospective Memory, Concurrent Task Management, and Pilot Error

national airport (LAX) cleared a commuter aircraft to position and hold on runway 24L while she worked to clear other aircraft to cross the other end of the runway. There were several communications delays because one of the other aircraft was on the wrong radio frequency. Visibility was poor at twilight because of haze and glare. The controller’s workload was considered moderate by air traffic controllers, although laypeople might consider it quite busy. The controller forgot to clear the commuter aircraft to take off and cleared another aircraft to land on 24L, which it did, destroying both aircraft and killing 34 people. Similar errors by pilots have also led to major accidents. In 1994, an airliner ran off the runway at LaGuardia airport after the crew rejected the takeoff at high speed because they observed anomalous indications on their airspeed indicators. The National Transportation Safety Board (NTSB) determined that the anomalous indications occurred because the crew failed to turn on the pitot heat, a normal procedural step that keeps the pitot input to the airspeed indicators from freezing in cold, wet weather. Two previous major airline accidents occurred in the 1980s when the crews forgot to extend wing flaps and slats to takeoff position, a normal procedural step required before takeoff. More recently, in 1996, an airliner landed gear-up in Houston when the landing gear failed to extend because the crew forgot to set the hydraulic pumps to the high position, which was part of the normal procedure for preparing their type of aircraft for landing. Obviously, multiple factors were at play in each of these accidents, but a central aspect of each accident was the failure of the crew to execute a simple procedural step that they had performed many thousands of times during previous flights. In everyday life we are all susceptible to forgetting to perform intended actions. These everyday lapses are mainly annoying and sometimes embarrassing, but in the operational world memory lapses can be fatal, as these accidents testify. Memory lapses during airline flight operations are particularly striking because the