Loose clamp leads to accident — General Aviation News

By General Aviation News Staff · April 14, 2023 · 7 Comments

On the day of the accident, the pilot decided to take his Mooney M20C on a flight around the traffic pattern at his home airport in Warwick, New York, to practice a few takeoffs and landings.

After pulling the airplane out of the hangar, he performed a preflight inspection. He then performed an engine run-up, then back taxied on the runway for takeoff.

Once he was in position for takeoff, he advanced the throttle until it was full open, and at 65 mph and about 2/3rds of the way down the runway, he rotated. He immediately realized that the engine was not producing full power, and attempted to advance the throttle further, but the throttle seemed as though it was not advancing completely. He then nosed the airplane down to attempt to stay in ground effect and gain some airspeed.

A lake was at the departure end of the runway, and he was already approaching trees on the opposite bank. He then picked a spot between the trees, turned the fuel off, and pulled the aircraft into a full stall prior to impact.

Post-accident examination of the airplane revealed that the fuselage and wings were substantially damaged. The pilot sustained serious injuries in the crash.

Further examination revealed that the throttle cable would resist efforts to fully open the throttle and would only move the throttle arm on the carburetor about 1/2 an inch, and when the throttle was fully open, the entire throttle cable would move through the firewall and bulge. After disconnecting the cable from the carburetor, the cable was found to be still under load, until a loose stand-off clamp that connected the throttle cable to the firewall was repositioned, which then allowed the throttle to function properly through its full range of motion.

Probable Cause: A loose stand-off clamp, which resulted in a throttle assembly malfunction, and the inability of the engine to produce full power during the attempted takeoff.

NTSB Identification: 103004

To download the final report. Click here. This will trigger a PDF download to your device.

This April 2021 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.