- Date
- March 9, 1994, 17:00 local (Mar 10, 1994, 01:00 UTC)
- Place
- Scapp00se, OR
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Landing
- Aircraft
- N51PLUnrein 80-P51D
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 2, 1994
- Report
- Approved by Office Director
- Case key
- 41893
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The NTSB’s determination of the probable cause, and any contributing factors.
The inadvertent unlocking of the tailwheel lock. Factors include the manufacturer's inadequate tailwheel lock.
Analysis
The aircraft's tailwheel locking mechanism inadvertently unlocked either during flight or upon touchdown for the full-stop landing. With the tailwheel free to pivot, the pilot lost control of the aircraft during the landing roll, and the main landing gear collapsed from overload. The pilot/manufacturer stated that he would now redesign the mechanism so that it could not be accidentally unlocked.
Factual narrative
On March 3, 1994, approximately 1700 Pacific standard time (PST), an experimental Unrein 80-P51D, N51PL, experienced a gear collapse during the landing roll at Scappoose Industrial Airpark, Scappoose, Oregon. The private pilot, who was the sole occupant of the aircraft, was not injured, but the aircraft sustained substantial damage. The personal pleasure flight, which departed Kelso-Longview Airport about 15 minutes earlier, was in visual meteorological conditions at the time of the accident. There was no flight plan filed, and there was no report of an ELT activation.
According to the pilot, the tailwheel locking mechanism accidently released either during flight or upon touchdown for a full-stop landing. With the tailwheel free to pivot, the pilot was unable to maintain directional control, and during the landing roll, the main gear was overloaded and collapsed.
The pilot advised the FAA inspector who responded to the accident that he would redesign the tailwheel locking system so that it could not inadvertently unlock.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Aircraft
- Registration
- N51PL
- Reported as
- Unrein 80-P51D
- Category
- Airplane, amateur-built
- Serial number
- 001
- Airframe hours
- 21
- Engine
- Continental E-185-11, 205 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Registered owner
- Unrein, Paul & Loretta
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Continuous airworthiness · January 25, 1994 · 21 hours before
- Departed
- KLS · Kelso, WA
- Airport
- 1S4 · Scappoose Industrial
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 51
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Valid Medical--no waivers/lim.
- Seat
- Front
- Flight hours
- 1,631 total · 21 in this make and model · 1,578 as pilot in command
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 25 statute miles
- Lowest ceiling
- 4,500 ft overcast
- Temperature
- 50 °F
- Altimeter
- 30.00 inHg
Other investigations on N51PL · 1
Matched to the same aircraft by N-number and date.