Beech B36TC accident near Mona, Utah, April 22, 1992
On April 22, 1992, a Beech B36TC, registered N7252X, was substantially damaged in an accident near Mona, Utah. It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A FATIGUE FAILURE TO THE CRANKSHAFT AND A MANUFACTURING MATERIAL DEFECT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 22, 1992
- Place
- Mona, Utah · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech B36TC · all B36TCs on the register
- Registration
- N7252X · no longer on the register · serial EA-450
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
DURING A CROSS COUNTRY FLIGHT, THE PILOT REPORTED THAT THE ENGINE LOST POWER WHILE IN CRUISE FLIGHT. THE PILOT DECLARED AN EMERGENCY AND INITIATED A FORCED LANDING TO AN OPEN FIELD. DURING THE LANDING ROLL, THE AIRPLANE COLLIDED WITH A DITCH. DURING AN ENGINE EXAMINATION, IT WAS FOUND THAT THE CRANKSHAFT WAS BROKEN BETWEEN THE NUMBER TWO MAIN JOURNAL, EXTENDING TO THE NUMBER TWO MAIN JOURNAL CHEEK AND NUMBER TWO CONNECTING ROD JOURNAL. A METALLURGICAL EXAMINATION REVEALED AN OCCLUDED MATERIAL WHICH APPEARED TO BE OXIDES OR OTHER NON METALLIC INCLUSIONS PRODUCED DURING THE MANUFACTURE OF THE METAL PRIOR TO FORGING. THE METALLURGICAL REPORT STATED,'THESE OXIDES MOST LIKELY PROVIDED STRESS RISERS WHICH CONCENTRATED STRESSES IN THE CRANKSHAFT TO DEVELOP CRACKS UNDER CYCLIC LOADING.' THE CRACKS PROPAGATED UNTIL FAILURE OCCURRED.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: private
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 1,398 hours in all; 319 in this make and model; 38 in the last 90 days; 14 in the last 30 days; 1,277 as pilot in command
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,248 hours
- Last inspection: annual inspection, June 21, 1991; 122 hours since
- Maximum gross weight: 3,850 lb
- Seats: 6
- Landing gear: retractable
- Engine: Continental TSIO-520-UB (piston); 0 hours total
The flight
- Departed from: Mt Carmel UT at 11:45 pm
- Destination: SLC Salt Lake City UT
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 090° at 10 knots
- Visibility: 20 statute miles
- Sky: not recorded; scat at 5,000 ft
- Temperature: 64°F (18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N7252X the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.