Mooney M20F accident near Fort Collins, Colorado, August 29, 1998
On August 29, 1998 at about 9:55 pm local time, a Mooney M20F, registered N377X, was destroyed in an accident near Fort Collins, Colorado. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's inadvertent stall/mush due to his excessive angle of bank during his traffic pattern turn to base. Factors were the pilot's improper downwind altitude, the pilot not properly setting his Kollsman Window in his altimeter, and the high density altitude.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 29, 1998 · about 9:55 pm local time
- Place
- Fort Collins, Colorado · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Mooney M20F · all M20Fs on the register
- Registration
- N377X · registry record · serial 670360
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot was returning from a cross-country flight and was observed by witnesses to enter the traffic pattern downwind at an estimated 450 feet agl and very close to the runway. One witness reported that when the aircraft turned base it 'appeared to be a kind of wing-over maneuver.' Another witness said that he 'turned left to the base leg of an approach to runway 11, and [he] quickly increased the bank so that in less than five seconds I could see a full plan view of the airplane at an altitude of approximately 200 feet.' Post-accident investigation indicated that the airplane's bank angle was approximately 30 degrees to the left and 30 degrees nose down upon ground impact. The airport (elevation 4,935 feet, density altitude 7,844 feet) had a local published traffic pattern altitude of 800 feet agl. Post-accident examination of the airplane's altimeter revealed a Kollsman Window setting of 29.96 inches. The closest recorded weather station (7 nautical miles distant and 81 feet above the destination airport elevation) was reporting a barometric pressure of 30.21 inches of mercury. The pilot's altimeter read approximately 250 feet higher than the airplane's actual altitude.
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: commercial pilot
- Ratings: single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 3,210 hours in all; 1,455 in this make and model
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 1,053 hours
- Last inspection: annual inspection, March 12, 1998; 17 hours since
- Maximum gross weight: 2,740 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming IO-360-A1A (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: CDR Chadron NE at 7:45 pm
- Destination: 3V5 CO
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 140° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 90°F (32°C), dew point 39°F (4°C)
- Altimeter: 30.00 inHg
- Observation at 9:56 pm from FNL, 7 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
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.