Casualties unknown

1991-08-17: Ercoupe (eng & Research Corp.) 415C (N2069H) — Walter J. Smith — Anaconda, MT

Anaconda, MT, US

On August 17, 1991, an Ercoupe (eng & Research Corp.) 415C (registration N2069H) operated by Walter J. Smith was involved in an aviation accident near Anaconda, MT. Investigators recorded the probable cause as: The pilot attempted takeoff at a high density altitude with the aircraft fully fueled and near maximum gross weight, and did not adjust the fuel/passenger load to compensate. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A pilot attempted takeoff at an airport with density altitude of 7500-8000 feet under no wind. The aircraft, near max gross weight and fully fueled, stalled due to decaying airspeed and descended back to the runway. Insufficient altitude precluded recovery.

Incident Description

A pilot attempted to depart from an airport where the density altitude was calculated to be between 7,500 and 8,000 feet. There was no wind during the takeoff attempt. The aircraft was fully fueled and operating near its maximum gross takeoff weight. The pilot did not reduce the fuel or passenger load to account for the high density altitude conditions.

During the takeoff roll, the airspeed decreased below the stall speed, causing the aircraft to stall. It then descended back onto the runway. Because the stall occurred at a low altitude, there was insufficient height available for the pilot to execute a successful recovery.

Aircraft and Operational Factors

The aircraft was loaded to near its maximum allowable takeoff weight, with full fuel tanks. The high density altitude significantly reduced the aircraft's performance capability, yet no adjustments were made to the load. The absence of wind further degraded takeoff performance.

Sequence of Events

Upon initiating the takeoff, the aircraft accelerated along the runway. However, the airspeed failed to increase sufficiently and eventually decayed to below the stall speed. The subsequent stall caused the aircraft to lose lift and contact the runway again. The pilot was unable to recover the aircraft before the runway ended due to the minimal altitude at which the stall occurred.

Probable cause

The pilot attempted takeoff at a high density altitude with the aircraft fully fueled and near maximum gross weight, and did not adjust the fuel/passenger load to compensate. During takeoff, airspeed decayed below stall speed, resulting in an aerodynamic stall and descent to the runway, with insufficient altitude for a successful recovery.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X17988. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.