Loss of Control in Flight · NTSB ANC22LA004

GREGG ORIGER PA-18 REPLICA — Willow, AK

1 fatal High-time pilot
DateOctober 24, 2021
LocationWillow, AK
AircraftGREGG ORIGER PA-18 REPLICA (amateur-built)
Purpose of flightPersonal
ConditionsDay · Visual Meteorological Cond
Phase / occurrenceApproach Loss of control in flight
Pilot age53
Pilot total time5,500 hrs · High time
Time in typeUnknown
Fatalities1, 1 serious

Probable cause

The pilot's exceedance of the airplane’s critical angle of attack while maneuvering for landing, which resulted in an aerodynamic stall and loss of control.

NTSB findings

  • Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Airspeed-Not attained/maintained
  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Angle of attack-Not attained/maintained

What happened

The pilot was landing his experimental, amateur-built airplane at a private airport when the airplane impacted terrain in a nose-down, near-vertical attitude short of the runway.

A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. No significant tree impacts were observed on the airframe. Based on the available information, it is likely that the pilot exceeded the airplane’s critical angle of attack while maneuvering for landing, which resulted in an aerodynamic stall and loss of control.

At the pilot’s request, numerous design changes were incorporated into the wings, ailerons, and flaps of the accident airplane. The manufacturer of the kit and the designer of the flaps stated that they told the pilot and builder that the design changes were not recommended; however, the kit was built to the pilot’s specifications. It is likely that the design changes affected the stall characteristic of the airplane; however, the role those changes played in the accident sequence could not be determined.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.

View the official NTSB docket →