Cessna 172M N1399U accident near Santa Ana, California

Probable cause

The flight instructor’s failure to maintain clearance from a commercial airliner which resulted in an encounter with wake turbulence and subsequent loss of control resulting in impact with terrain.

NTSB analysis

The flight instructor reported that while practicing crosswind landings with his student, the tower advised the pilot of wake turbulence from a commercial airliner on the parallel runway. They flew a steeper approach but noticed a moderate right quartering headwind on the windsock. At about 100 feet above ground level the airplane encountered wake turbulence and banked sharply to the right. Both pilots added full left aileron and applied backpressure to the yoke as the airplane contacted the terrain. The airplane sustained substantial damage to the right wing.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR23LA146 for the full record.