Beech 35-C33 N18AR accident near Longmont, Colorado

Probable cause

The airplane’s lack of climb performance after takeoff in high density altitude conditions for reasons that could not be determined based on the available evidence.

NTSB analysis

The pilot was departing on a personal flight with a density altitude of 6,804 ft. After takeoff, the airplane’s climb rate “did not look normal,” and the pilot was not certain that the airplane would clear a house located along the departure path. He decided to execute a precautionary landing to a hayfield about 1/3 mile from the departure end of the runway. The pilot retracted the landing gear, and the airplane touched down and slid to a stop on its belly.

Airplane performance data indicated that the expected initial rate of climb was about 780 ft per minute. Airframe and engine examinations did not reveal any anomalies consistent with an inability to maintain the published rate of climb or to produce rated engine power. Therefore, the investigation was unable to determine the reason for the lack of climb performance. Regardless, the pilot’s decision to execute a precautionary landing under the circumstances was prudent.

Text from the NTSB. Open the NTSB docket for CEN21LA325 for the full record.