Cirrus Design Corp SR22 N432CP accident near Tredyffin, Pennsylvania

Probable cause

The loosening of the throttle arm from the throttle body, which resulted in the pilot’s inability to control the engine, and a subsequent forced landing.

NTSB analysis

According to the pilot while approaching the destination airport, the engine did not respond when he advanced the throttle. He also noted that the throttle felt “loose” and further described that the engine was still running, but that the rpm would not change. There was not sufficient engine power being produced in order for the airplane to reach the destination airport, so the pilot elected to perform an off-airport landing to a golf course. The airplane was substantially damaged during the landing, and the pilot and passenger were seriously injured.

A postaccident examination of the engine found that the engine’s controls were damaged during the accident sequence and had separated from the engine. Additionally, the throttle arm was found loosely attached to the shaft at the throttle body. The nut needed to be tightened by 1/8-turn in order to fully engage. No other anomalies were noted during the examination that would have precluded normal operation of the engine. Review of the airplane’s maintenance records revealed that the engine controls had been inspected and lubricated about 7 months and 37 flight hours before the accident, with no subsequent maintenance to those components noted. Based on the pilot’s description that the engine did not respond to throttle changes and that it felt “loose,” as well as the finding that the throttle arm was found loosely attached to the throttle shaft, it is likely that the loosening of the securing nut resulted in the pilot’s inability to control the engine, and the subsequent forced landing.

Text from the NTSB. Open the NTSB docket for ERA22LA254 for the full record.