On July 30, 1994, a Wsk Pzl Mielec M18S (registration N81705) operated by Brown Boy Aviation was involved in an aviation accident near Royal City, WA. Investigators recorded the probable cause as: The pilot's inability to clear a hill due to inadequate performance during takeoff, which was contributed to by a tailwind and high temperature. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft failed to gain sufficient altitude during takeoff on a hot day with a tailwind, resulting in an overrun at the end of the airstrip. The pilot attempted to lighten the load but could not clear a nearby hill.
What happened
The pilot initiated the takeoff roll and reported that operations appeared normal initially. However, as the aircraft approached the end of the runway, it failed to achieve flight. In an attempt to reduce weight, the pilot jettisoned cargo or fuel, but this action was insufficient to allow the aircraft to clear a hill located at the terminus of the airstrip.
The investigation
An FAA inspector reviewed the circumstances surrounding the incident. The investigation identified specific environmental conditions that negatively impacted performance. A tailwind component and ambient temperatures reaching 100 degrees Fahrenheit were cited as primary contributors to the aircraft's inability to clear the obstacle.
Findings
The failure to become airborne was directly linked to high density altitude conditions caused by the extreme heat and wind direction. These factors degraded lift generation, preventing the pilot from achieving the necessary climb gradient over the terrain at the end of the runway.
Probable cause
The pilot's inability to clear a hill due to inadequate performance during takeoff, which was contributed to by a tailwind and high temperature.