What happened
During the initial takeoff climb, the pilot of a Cessna (type not specified in source) performed a forced landing into an open field. Prior to the accident, the pilot had expressed concerns to State Police regarding the aircraft's weight and potential performance issues related to hot weather. During the takeoff roll, the aircraft was slow to accelerate, which the pilot attributed to hot and humid conditions. The aircraft utilized approximately 3,000 feet of the 4,150-foot runway before reaching an airborne speed of 80 mph. The initial climb rate was approximately 50 feet per minute, which was noted as being well below normal.
As the aircraft approached a tree line located roughly 1,500 feet from the end of the runway, it lost its ability to climb and began a descent. The pilot reported that the engine was at full power. Just before reaching the trees, the pilot transitioned the flaps from one notch to the full down position. The aircraft skimmed the tops of the trees and struck the ground in a nose-down, right-wing-low attitude. The impact caused the aircraft to catch fire, resulting in the total destruction of the airplane. The pilot was not injured.
The investigation
Investigators determined that the takeoff weight for the flight ranged between 1,816 pounds and 1,981 pounds based on three different computations using various baggage weights and the manufacturer's empty weight. At the time of departure, the temperature was 82 degrees Fahrenheit with a dew point of 72 degrees Fahrenheit and an altimeter setting of 29.88. These conditions resulted in a density altitude of 1,755 feet.
While the manufacturer's performance figures for takeoff with flaps extended were based on sea level standard conditions, the actual density altitude would have increased the required takeoff run by approximately 43 percent. Specifically, the takeoff run was estimated to increase to 1,745 feet, and the distance required to clear a 50-foot obstacle would have increased to 2,288 feet. Post-accident inspection of the aircraft revealed no evidence of any mechanical anomalies prior to the impact.
Findings
- The pilot did not conduct formal written performance planning for the flight, relying instead on mental calculations of weight and balance.
- The pilot failed to account for the effects of density altitude and pressure altitude on takeoff performance.
- The pilot did not establish a specific go or no-go point on the runway to abort the takeoff based on the environmental conditions.