Piper PA-24-250 N7171P accident near Shawnee, Oklahoma

Probable cause

The improper installation of the mixture cable by maintenance personnel, which allowed the mixture cable to entangle with the landing gear during gear extension and led to the subsequent loss of engine power.

NTSB analysis

The pilot was conducting the second leg of the airplane’s first flight after a recent engine overhaul. On final approach, the pilot lowered the landing gear handle; however, he did not receive confirmation that the landing gear was down. The pilot stated that he applied a lot of force to conduct the manual gear override but that he was not able to get the handle up. Shortly thereafter, the engine lost power. The airplane was substantially damaged during the subsequent forced landing. A postaccident examination of the airplane revealed that the mixture cable was bent, the cable was pulled from its last clamp prior to the carburetor mixture control, and the mixture control was pulled into the cutoff position. The routing of the mixture cable did not match assembly drawings, and several clamps used to route the mixture cable were missing. A grease fitting on the over-center link for the nose landing gear was in line with the bend in the mixture cable. Most likely, the landing gear center link became entangled in the mixture control cable, which prevented the nose landing gear from extending. The mixture likely came to idle when the pilot used extra force to try to extend the landing gear. The mixture cable was not installed properly during the recent engine overhaul.

Text from the NTSB. Open the NTSB docket for CEN12LA299 for the full record.