- Date
- January 19, 1993, 18:10 local (Jan 20, 1993, 01:10 UTC)
- Place
- Medicine Bow, WY
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N56924Boeing A75N1
- Weather
- Night/dark
- Status
- Completed · report October 13, 1993
- Report
- Approved by Office Director
- FAA report
- 19930119002529A
- Case key
- 42978
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 #7 cylinder rocker arm. Factors contributing to the accident were unsuitable terrain and dark night conditions.
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 shortly after levelling off at 14,000 feet MSL, the engine surged three times and then stopped. A forced landing was executed onto rocky, upsloping terrain, under dark night conditions. Subsequent disassembly of the engine revealed that the number 7 cylinder intake valve rocker arm had failed.
Aircraft
- Registration
- N56924
- Reported as
- Boeing A75N1
- Category
- Airplane
- Serial number
- 75-2480
- Airframe hours
- 6,601
- Engine
- P&W R-985-AN1, 450 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Denton, Larry E.
- Registered owner
- Denton, Larry E.
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Annual · January 2, 1993 · 10 hours before
- Departed
- RKS · Rock Springs, WY
- Destination
- LAR · Laramie, WY
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 57
- Certificates
- Flight instructor, Commercial
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Rear
- Flight hours
- 9,999 total · 9,999 in this make and model · 9,999 as pilot in command · 40 in the last 90 days · 5 in the last 24 hours
Weather
- Conditions
- Night/dark
- Wind
- 250° at 14 knots
- Visibility
- 7 statute miles
- Lowest ceiling
- 1,500 ft overcast
- Temperature
- 25 °F, dew point 21 °F
- Altimeter
- 29.00 inHg
- Observed at
- RWL, 43 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.