- Date
- August 13, 1989, 11:11 local (18:11 UTC)
- Place
- Seligman, AZ
- Injuries
- 2 minor, 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N5961JCessna 172N
- Weather
- Visual (VMC) · Day
- Status
- Completed · report September 30, 1991
- Report
- Approved by Office Director
- Case key
- 26476
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 loss of engine power due to a failure of the number 3 cylinder exhaust valve rocker arm pivot stud, which was in turn caused by a stuck exhaust valve.
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 pilot reported that while in cruise flight, a severe vibration began in the engine with a corresponding reduction in engine RPM to about 1500. The pilot noted that all attempts at remedial action met with no success and the engine was producing insufficient power to maintain flight. The pilot attempted to land on an interstate highway but there was too much vehicle traffic to make a safe landing. The pilot then landed in a dirt field adjacent to the highway, contacted a large berm during the landing roll out and the aircraft nosed over on its back. Examination of the engine revealed heavy deposits on the intake and exhaust valves. The exhaust valve for the number 3 cylinder was in the closed position and could not be moved. Detailed examination of the number 3 cylinder revealed that the rocker arm pivot stud for the exhaust valve was broken with shear signatures evident.
Aircraft
- Registration
- N5961J
- Reported as
- Cessna 172N
- Category
- Airplane
- Serial number
- 17273847
- Airframe hours
- 6,130
- Engine
- Lycoming O-320-H2AD, 160 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- North Air, Inc.
- Registered owner
- Gerald J. Fitzgerald
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · June 26, 1989 · 37 hours before
- Departed
- PRC · Prescott, AZ
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
- 24
- Certificates
- Flight instructor, Commercial
- Airplane ratings
- Multi-engine land, Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 768 total · 91 in this make and model · 551 as pilot in command · 3 in the last 90 days · 3 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 40 statute miles
- Lowest ceiling
- None
- Temperature
- 70 °F