Mooney M20F accident near San Manuel, Arizona, December 28, 1985
On December 28, 1985, a Mooney M20F, registered N234GA, was substantially damaged in an accident near San Manuel, Arizona (San Manuel airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 4 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 28, 1985
- Place
- San Manuel, Arizona · San Manuel · map
- Type
- Accident
- Injuries
- No one was hurt; 4 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mooney M20F · all M20Fs on the register
- Registration
- N234GA · registry record · serial 680036
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
DURING CRUISE AT 10,500 FT MSL ON A NIGHT X-COUNTRY FLT, THE PLT SAID THE ENG RAN ROUGH WITH MODERATE VIBRATION LEVELS. PLT DECLARED AN EMERGENCY WITH ABQ ARTCC, WHO VECTORED THE ACFT TO AN UNLIGHTED AIRSTRIP. THE PLT SAID HE HAD DIFFICULTYIN SEEING THE RWY IN THE DARKNESS. THE ACFT LANDED LONG, BLEW A TIRE, VEERED OFF THE RT SIDE OF THE RWY & STRUCK A TREE.EXAMINATION OF THE ENG REVEALED THAT THE #3 CYLINDER WAS AJAR FROM THE CASE, WITH ALL THE TOP HOLD DOWN STUDS & NUTS IN PLACE BUT BENT UPWARD. THE NUTS WERE MISSING FROM THE LOWER FORE & AFT LARGE HOLD DOWN STUDS, & THE REMAINING CENTER STUDS HAD ALL FRACTURED AT THE CYLINDER FLANGE LEVEL. THE ENG WAS OVERHAULED 6 MONTHS AND 21 HRS PRIOR TO THE ACCIDENT. THE FAA AIRWORTHINESS INSPECTOR WHO EXAMINED THE ENG STATED HIS OPINION THAT THE NUTS ON THE LOWER LARGE STUDS WERE UNDERTORQUED AT INSTALLATION.
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: airline transport pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 7,600 hours in all; 700 in this make and model; 45 in the last 90 days; 16 in the last 30 days; 7,300 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,510 hours
- Last inspection: annual inspection, May 3, 1985; 21 hours since
- Maximum gross weight: 2,600 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming IO-360-A1A (piston); 0 hours total
The flight
- Departed from: ELP El Paso TX at 11:45 pm
- Destination: PHX Phoenix AZ
- Flight plan: VFR
- Runway 29, 4,200 ft by 50 ft
Weather at the time
- Light: dusk
- Wind: from 270° at 10 knots
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 32°F (0°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 3 |
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.
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.