Casualties unknown

2007-09-21: Robinson R-22 BETA (N2341J) — Corvallis Aer Service — Bend, OR

Bend, OR, US

On September 21, 2007, a Robinson R-22 BETA (registration N2341J) operated by Corvallis Aer Service was involved in an aviation accident near Bend, OR. Investigators recorded the probable cause as: The pilot's excessive angle of approach and application of too much collective during a pinnacle approach, which resulted in a rotor stall and subsequent collision with terrain. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A helicopter sustained substantial damage after a pilot attempted a pinnacle approach and landing during a check ride, resulting in a rotor stall and terrain collision.

What happened

The incident occurred while the pilot was conducting a check ride. The specific objective of this phase of flight was to demonstrate proficiency in performing a pinnacle approach and subsequent landing. During the execution of this maneuver, the pilot reported that the angle of approach was excessive. In an attempt to correct the trajectory or maintain lift, too much collective pitch was applied. This combination of factors led directly to a rotor stall.

Following the loss of rotor efficiency, the helicopter collided with the terrain. The impact caused the aircraft to roll over. As a result of this sequence of events, the helicopter sustained substantial damage. No further details regarding injuries or specific location were provided in the source record.

The investigation

The primary basis for the assessment of this accident is the pilot's own statement regarding the operational parameters at the time of the event. The pilot identified the excessive angle of approach and the application of excessive collective as the direct precursors to the rotor stall. No mechanical examination or external forensic data was included in the provided source text.

Findings

The analysis indicates that the rotor stall was the critical failure mode leading to the loss of control. The contributing factors were identified as:

  • An angle of approach that was too great for the specific maneuver conditions.
  • The application of too much collective pitch in response to the approach angle.

These actions resulted in the helicopter colliding with terrain and rolling over, causing substantial damage to the airframe.

Probable cause

The pilot's excessive angle of approach and application of too much collective during a pinnacle approach, which resulted in a rotor stall and subsequent collision with terrain.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20071012X01584. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.