Event Description
At night, with minimal traffic, a Beech 58 landed and was retained on the local control frequency for the pilot's convenience. The pilot requested clearance to the TWA hangar and was cleared via the most expeditious route. This route passed next to the runway 9L pad, where a Boeing 747 maintenance crew was conducting engine run-ups and trimming. As the Beech 58 passed behind the Boeing 747, it was blown over. During the event, the top of the Beech was crushed inward, resulting in fatal injuries to the pilot.
Operational Details
The tower's letter of operations prohibited the use of the taxiway adjacent to the runway 9L pad when that pad was being used for run-ups. The pilot of the Beech was not cautioned about possible wake turbulence, and the Boeing crew was not advised of the Beech's position. For noise abatement purposes, the night-time run-up of the Boeing 747 should have been conducted on a heading of east or northwest, but the 747 was positioned on a southwest heading, angled into the wind. None of the four tower controllers on duty detected this orientation or attempted to correct it.
Regulatory and Procedural Aspects
The incident highlights deviations from established procedures. The use of a prohibited taxiway during a run-up, the lack of coordination between ground and maintenance crews, and the failure to follow noise abatement headings all contributed to the circumstances. However, the investigation did not specify a probable cause.