Schweizer 269C N958CP accident near Las Vegas, Nevada

Probable cause

The certificated flight instructor's delayed remedial action, and inadequate supervision while landing on a pinnacle. Factors contributing to the accident were the lack of suitable terrain for a forced landing, and the student's failure to maintain rotor rpm.

NTSB analysis

The certificated flight instructor (CFI) and student were practicing pinnacle approaches. During the last 50 feet of the approach, the main rotor rpm began to decay as the student was raising the collective. The CFI advised the student to roll on some throttle, and also reached for the throttle. The student continued to increase the collective, and the main rotor rpm decayed further. The instructor took full control of the helicopter and completed a steep slope landing. After the helicopter was on the ground, the instructor found that half of the collective was pulled in as well as full right cyclic in order to keep the helicopter stable on the slope. The CFI lifted the helicopter from the slope, and started to go into a hover, slowly letting the helicopter drift to the left away from the slope. The helicopter started to settle, and the instructor could not lower collective to roll the throttle on to gain power. The helicopter was continuing a drift to the left when the tail stinger and tail rotor contacted something on the slope. The helicopter began an immediate and rapid right yaw. The CFI rolled the throttle off to arrest the rotation, and the helicopter stopped spinning. The helicopter landed softly, but rolled over due to the steepness of the slope. The pilot reported no prior mechanical malfunctions.

Text from the NTSB. Open the NTSB docket for LAX08CA069 for the full record.