American General Acft Corp AG5B N1191W accident near Naples, Florida

Probable cause

A partial loss of engine power during takeoff for undetermined reasons.

NTSB analysis

The airplane was fully loaded and departed from a 4,400-foot-long asphalt runway, in a slight tailwind. The owner of the airplane loaned it to the pilot and witnessed the accident takeoff. The airplane lifted off about half-way down the runway, climbed approximately 150 feet and appeared to be well above the height of the trees. It then started to sink and disappeared into the trees at an increased pitch attitude. According to a pilot-rated passenger, the liftoff and initial climb appeared normal, but soon it was apparent that the airplane was not accelerating. The passenger mentioned to the pilot that the airspeed seemed to be stagnating and he confirmed the same concern. The pilot and passenger both checked for full throttle position and rpm, which was at 2,150, instead of an expected rpm of 2,300. The passenger stated that at that point the only option was to lower the nose in an attempt to increase airspeed. When there was no increase in airspeed, they both realized that the airplane would impact trees. The pilot continued to fly the airplane straight and level to the point of impact. Examination of the wreckage, including a test-run of the engine to full power, did not reveal any evidence of a preexisting mechanical failure or malfunction. The airplane was destroyed in the accident.

Text from the NTSB. Open the NTSB docket for ERA09LA055 for the full record.