- Date
- July 31, 1992, 10:49 local (15:49 UTC)
- Place
- Cibolo, TX
- Injuries
- 1 fatal
- Damage
- Destroyed
- Phase of flight
- Approach
- Aircraft
- N62552Boeing A75
- Weather
- Visual (VMC) · Day
- Status
- Completed · report June 30, 1993
- Report
- Approved by Office Director
- FAA report
- 19920731028449A
- Case key
- 18367
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
Failure of the engine crankshaft due fatigue and the resultant collapsing of the left wing.
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 commercial pilot had been troubleshooting a vibration present in his airplane for the last 10 flight hours. After the blade angles on the propeller blades were realigned he flew the airplane to check the vibration level. While on a left downwind, the propeller separated from the engine and severed a wing strut and portion of the left wing. After both of the biplane's left wings collapsed, the airplane entered a left vertical spiral and impacted in an open pasture. Separation of the crankshaft was a result of fatigue originating in the threads at a position normally in line with the aft face of the thrust nut. The thrust nut also failed in fatigue. Nut configuration was different from the configuration indicated in the engineering drawing. However, it was not established if this was a contributing factor to the failure. There was also no evidence of over torque during installation.
Aircraft
- Registration
- N62552
- Reported as
- Boeing A75
- Category
- Airplane
- Serial number
- 75-3190
- Airframe hours
- 601
- Engine
- Continental W670-6A, 220 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Personal · Part 91
- Operator
- Perdue, Harold F.
- Registered owner
- Perdue, Harold F.
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · December 6, 1991 · 25 hours before
- Departed
- 15R
- Destination
- 15R
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
- 70
- Certificate
- Commercial
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Front
- Toxicology
- Performed
- Flight hours
- 5,500 total · 1,000 in this make and model
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 190° at 9 knots
- Visibility
- 7 statute miles
- Lowest ceiling
- 25,000 ft broken
- Temperature
- 82 °F, dew point 73 °F
- Altimeter
- 30.00 inHg
- Observed at
- RND, 22 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N62552 · 1
Matched to the same aircraft by N-number and date.