On August 13, 1985, a Learjet 23 (registration N61TS) was involved in an aviation accident near Madison, WI. Investigators recorded the probable cause as: The pilot's decision to abort the takeoff at high speed on a short, wet runway, which led to hydroplaning, loss of control, and a runway excursion resulting in gear collapse. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot aborted takeoff at 100 knots on a short runway due to hydroplaning, resulting in loss of control, left main gear collapse, and the aircraft coming to rest in a water-filled ditch.
What happened
The pilot elected to initiate takeoff with the aircraft heavily loaded onto a relatively short runway. As the aircraft accelerated down the departure end, the pilot reported hearing a loud noise as the airspeed approached 80 knots. Consequently, the decision was made to abort the takeoff at approximately 100 knots.
During the aborted takeoff roll, the aircraft experienced hydroplaning, which resulted in a complete loss of directional control. Unable to maintain runway alignment or stop within the remaining pavement, the aircraft traveled beyond the departure end of the runway. Upon leaving the paved surface, the left main landing gear collapsed under the stress of the excursion. The aircraft continued forward until it came to rest with its nose section embedded in a water-filled ditch adjacent to the runway environment.
The investigation
The physical evidence indicated that the heavy loading of the aircraft contributed to the takeoff performance issues on the short runway. The collapse of the left main gear was consistent with the forces generated during the off-runway excursion and subsequent impact with the terrain and water-filled ditch.
Probable cause
The pilot's decision to abort the takeoff at high speed on a short, wet runway, which led to hydroplaning, loss of control, and a runway excursion resulting in gear collapse.