# Accident 20230705007949A: Avia Stroitel AC-5M, Cornelius, OR, July 5, 2023

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: July 5, 2023, 11:50 local time
- Place: Cornelius, OR
- Damage: Destroyed
- Phase of flight: Cruise/Level Flight
- Operating rules: General operating rules (Part 91)
- Location: 45.5764° N, 123.0604° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=45.5764&lon=-123.0604&mi=10
- Aircraft: N40233, a cancelled registration (https://openairdocs.org/deregistered/N40233-2024-01-23) (OpenAirDocs)
- Registry model: Avia Stroitel AC-5M (registry code 05610QZ, https://openairdocs.org/model/avia-stroitel-ac-5m) (OpenAirDocs)
- Registry engine: NONE (registry code 00000, https://openairdocs.org/engine/none) (OpenAirDocs)
- Reported make and model: AVIA STROITEL AC-5M
- Reported engine: NONE NONE
- People aboard: 1
- Fatal injuries: 0
- Other injuries: 1
- Pilot certificates: Private pilot
- Pilot flight hours: 240 total
- NTSB investigation: [NTSB WPR23LA255](https://openairdocs.org/ntsb/WPR23LA255) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20230705007949A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

FOLLOWING A NORMAL TAKEOFF FROM NORTH PLAINS GLIDER PORT (1OR4) UNDER TOW FROM A TOW AIRCRAFT, THE PILOT RELEASED FROM THE TOW AIRCRAFT AT 3100' AGL AND MADE A 180 DEGREE CLEARING TURN WITHOUT INCIDENT AND TRIMMED AT 55 KNOTS, THE BEST LIFT TO DRAG SPEED.  HE THEN HEADED SOUTH OF HWY 26 AND DEPLOYED MOTOR FOR 15 -20 SECONDS CHECKING FOR DRAG BUT NOT AT FILL DEPLOYMENT.  THE MOTOR WAS RETRACTED TO THE DETENT POSITION AND SECURED WITH A CONTROL ROD AND THE ACCESS DOORS CLOSED WITH A SEPARATE CONTROL ROD.  THE PILOT ALSO MADE SHALLOW 20 DEGREE BANKS WITH STALLS AND RECOVERY TO THE LEFT, RIGHT, AND STRAIGHT.  THE PILOT WAS MAKING A 45 DEGREE BANK ABOVE 2000' AGL WHEN THE GLIDER STALLED AND DROPPED WHICH WAS MORE AGRESSIVE THAN THE PILOT EXPECTED AND CONTINUED OVER TO A SPIRAL DIVE DECENDING AT A RAPID PACE.  THE PILOT REPORTED NOT KNOWING WHAT INDUCED THE SPIN/STALL.  HE USED THE RUDDER TO TRY TO STOP ROTATION AND WAS UNSURE HOW MANY REVOLUTIONS THE GLIDER MADE.  WHEN THE PILOT WAS ABLE TO STABILIZE, GET THE WINGS LEVEL, HE VERIFIED THE AREA CLEAR, THE HORIZON IN VIEW, AND INITIATED A RETURN TO THE INITIAL POINT (IP) FOR A DOWNWIND TO THE GLIDER PORT.  AT THAT POINT THE GLIDER SHUDDERED AND THE PILOT HEARD A LOUD POP AND SAW THE RIGHT WING DEPART THE AIRCRAFT.  HE JETTISONED THE CANOPY, BAILED OUT OF THE GLIDER, AND PULLED THE D-RING OF HIS PARACHUTE.  WHILE UNDER PARACHUTE THE PILOT OBSERVED THE FUSELAGE IMPACT THE GROUND IN AN OPEN FIELD WHERE HE LANDED WITHIN 40 YARDS OF THE FUSELAGE.  THE PILOT BROKE A LEG UPON LANDING WITH OTHER MINOR INJURIES.  NO MAJOR INJURIES WERE SUSTAINED.  LOCAL LAW ENFORCEMENT REPORTED WITNESSES ON THE GROUND HEARD A LOUD POP AND OBERSERVED THE RIGHT WING DEPARTING THE GLIDER, THE FUSELAGE WING, AND TAIL SECTION FALL INTO THE OPEN FIELD.  THEY ALSO OBSERVED THE PILOT PARACHUTING TO THE GROUND AND ASSISTED THE PILOT AT THAT POINT.

DURING A SUBSEQUENT INTERVIEW WITH THE PILOT HE STATED THAT, HE WAS SURE THE MOTOR WAS LOCKED DOWN WITH THE CONTROL ROD AS WELL AS THE MOTOR ACCESS DOORS.  ALTHOUGH HE DEPLOYED THE DIVE BRAKES DURING THE PREFLIGHT THEY WERE NOT DEPLOYED IN FLIGHT.  HE DID NOT REMEMBER ANY SIGNIFICANT G-FORCES DURING THE RECOVERY BUT MAY HAVE EXCEEDED THE 120 KNOT VNE OF THE GLIDER.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB WPR23LA255](https://openairdocs.org/ntsb/WPR23LA255), Jul 5, 2023: Avia Stroitel AC-5M (N40233), North Plains, OR, substantial damage. Probable cause: The pilot’s failure to maintain control of the motor glider, which resulted in an inflight overstress separation of the right wing during a high-speed, high-wing-load spiral dive recovery.…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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