Cessna TR182 N756FZ accident near Torrance, California

Probable cause

The failure of the right main landing gear to fully extend for reasons that could not be determined because postaccident examination and testing did not reveal any evidence of preimpact mechanical failures or malfunctions that would have precluded normal operation.

NTSB analysis

During an instructional flight, the flight instructor was demonstrating a normal landing to the pilot under instruction. As the airplane approached the runway, the instructor selected the landing gear down and configured the airplane for the landing. The landing checks were called out, and a landing gear green indictor light was verified, indicating that the landing gear should have been down and locked. The landing flare and initial touchdown were normal. However, shortly after the airplane touched down, it listed right as the right main landing gear (MLG) collapsed. The airplane then entered a 180o skidding turn before coming to a stop. Two witnesses reported seeing the airplane on final approach with its right MLG not fully extended.

During a postaccident examination, the airplane was placed on jacks to facilitate a gear-swing test. The MLG were cycled multiple times with no evidence of any preimpact mechanical failures or malfunctions that would have precluded normal operation. Each time the MLG were extended, the landing gear indicator lights inside the cockpit illuminated. The reason for the right MLG's failure to fully extend when the MLG were selected down could not be determined.

Text from the NTSB. Open the NTSB docket for WPR16LA163 for the full record.