- Date
- September 25, 1991, 13:30 local (18:30 UTC)
- Place
- Pierre, SD
- Injuries
- 1 fatal
- Damage
- Destroyed
- Phase of flight
- Approach
- Aircraft
- NX39JRBoland/Poe Tsunami
- Weather
- Visual (VMC) · Day
- Status
- Completed · report March 31, 1993
- Report
- Approved by Office Director
- Case key
- 14881
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
A bending overload failure of the wing flap control rods and remedial action by the pilot was not possible. Factors in the accident are the inadequate design of the wing flap system by the pilot/operator manufacturer and his lack of total experience in type of aircraft.
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.
Analysis
The accident airplane was observed to suddenly roll inverted during final approach and descend into the ground. Investigation of the wreckage showed a bending overload failure of the external threaded stem type rod end bearing attached to the piston of each wing flap hydraulic actuator. The experimental racing airplane was originally built and flown without wing flaps. The wing flaps were added by the pilot/operator at a later date.
Aircraft
- Registration
- NX39JR
- Reported as
- Boland/Poe Tsunami
- Category
- Airplane, amateur-built
- Serial number
- 001
- Airframe hours
- 200
- Engine
- Rolls-Royce V-1650-7, 3,000 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Personal · Part 91
- Operator
- John Richard Sandberg
- Registered owner
- John Richard Sandberg
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Annual · January 2, 2000
- Departed
- CPR · Casper, WY
- Airport
- PIR · Pierre Municipal
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 59
- Certificate
- Private
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Unknown
- Seat
- Center
- Toxicology
- Performed
- Flight hours
- 9,975 total · 20 in this make and model
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 310° at 20 knots, gusting 28
- Visibility
- 45 statute miles
- Lowest ceiling
- None
- Temperature
- 68 °F, dew point 28 °F
- Altimeter
- 30.00 inHg
- Observed at
- PIR, 1 nm away