17 Jun 2008: Robinson R-22 Beta — Hillsboro Aviation Inc. — Philomath, OR

No fatalitiesPhilomath, OR, United States

A student pilot and flight instructor sustained minor injuries after a Robinson R-22 Beta struck terrain during a mountain landing maneuver.

What happened

On June 17, 2008, an instructional cross-country flight involving a Robinson R-22 Beta, registration N4000Y, was returning to its home base following a refueling stop at an airport near sea level. During the flight, the crew decided to perform a pinnacle landing on a mountain with an elevation of 4,060 feet.

At the time of the departure, weather conditions were VMC with winds from 300 degrees at 16 knots, gusting to 20 knots, and visibility of 10 statute miles. As the student pilot approached the mountain peak for the landing, the aircraft encountered a downdraft. This caused the main rotor disk low RPM indicators to activate. The flight instructor took control of the aircraft to attempt to recover, but the landing skid struck the terrain. The helicopter subsequently rolled twice down the mountainside. The flight instructor and the student sustained 2 minor injuries and were not fatal.

Probable cause

The accident was caused by the student pilot's failure to maintain rotor RPM during a pinnacle approach, combined with the flight instructor's inadequate supervision and delayed corrective actions. A downdraft also contributed to the event.

Contributing factors

Causes

Prop/rotor parameters — Not attained/maintainedInstructor/check pilot

Other contributing factors

Contributed to outcomeMountainous/hilly terrain