Aviation Accident Summaries

Aviation Accident Summary SEA02LA165

Melstone, MT, USA

Aircraft #1

N36596

Bellanca 7GCBC

Analysis

The pilot, who was attempting a takeoff in a 750 foot area in an open field, realized during the takeoff roll that the aircraft might not clear a known three foot ditch berm at the departure end of the takeoff area. Although he became unsure whether the aircraft would clear the obstacle, he continued the attempted takeoff, and both of the aircraft's main landing gear were torn from their mounts when they eventually collided with the berm. The density altitude was approximately 4740 feet, and the pilot, who had not performed any pre-takeoff performance calculations, had based his assumption that the aircraft could get off in the available distance upon the fact that a Piper Super Cub had successfully taken off from the field in the past.

Factual Information

On August 25, 2002, approximately 1200 mountain daylight time, a Bellanca 7GCBC, N36596, impacted the terrain during an attempted takeoff from an open field about seven miles west of Melstone, Montana. The private pilot and his passenger were not injured, but the aircraft, which is owned and operated by Sleeping Giant Flying Club, sustained substantial damage. The local VFR 14 CFR Part 91 personal pleasure flight was being initiated in visual meteorological conditions. No flight plan had been filed. According to the pilot, he was attempting a takeoff in an open field where approximately 750 feet was available prior to reaching a three foot ditch embankment. Although he knew the ditch was there, he thought the aircraft would get off the ground prior to reaching the point where the ditch crossed the field. He said that when he was about seven-eights of the way to the ditch, he realized the aircraft might not make it off in time, but he made the decision to continue the attempt anyway. The aircraft was ultimately unable to lift off prior to reaching the ditch, and when its main gear impacted the embankment, they were torn loose from their mounting points, and the aircraft slid about 150 feet over a plowed field. As it slid across the field, the wings and forward portion of the fuselage sustained substantial damage. The pilot said that as far as he could tell, there did not seem to be any problem with the aircraft or its engine. According to the FAA Inspector who interviewed the pilot after the accident, he had not done performance calculations prior to attempting the takeoff, but instead based his assumption that he could successfully execute the take off on the fact that a Piper Super Cub had landed and taken off in the same field in the past. Based upon the field elevation of 2,950 feet, the altimeter setting of 30.15, and a temperature of 78 degrees Fahrenheit, the density altitude was determined to be approximately 4,740 feet.

Probable Cause and Findings

The pilot's improper decision to continue a takeoff once it had become apparent that it was questionable whether the aircraft would clear an obstacle at the departure end of the takeoff area. Factors include the pilot's failure to perform pre-takeoff performance calculations, a high density altitude, and a ditch berm at the end of the area the pilot was using for the attempted takeoff.

 

Source: NTSB Aviation Accident Database

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