Piper PA-31-350 accident near Greeley, Colorado, May 28, 1997
On May 28, 1997 at about 1:00 am local time, a Piper PA-31-350, registered N491SC, was substantially damaged in an accident near Greeley, Colorado. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 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
unlatching of the left outboard engine cowling latches for undetermined reason(s), which allowed the left engine cowling to separate inflight and strike the vertical stabilizer.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 28, 1997 · about 1:00 am local time
- Place
- Greeley, Colorado · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-31-350 · all PA-31-350s on the register
- Registration
- N491SC · registry record
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The pilot said that while in cruise flight, he observed the left front portion of the left engine cowling starting to come loose. After receiving clearance from air traffic control, he started to divert to the nearest suitable airport. Shortly thereafter, the left cowling completely separated from the aircraft and struck the vertical stabilizer. Postaccident inspection disclosed the outboard cowling latches were in the UNLOCKED position, and the inboard latches were in the LOCKED position. A portion of the cowling remained attached via the inboard latches. The pilot said he checked the cowling latches during his preflight inspection and they were all in the LOCKED position. Orange stripes had been painted across the latches to visually indicate LOCKED and UNLOCKED positions.
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, flight instructor
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 2,250 hours in all; 600 in this make and model; 200 in the last 90 days; 80 in the last 30 days; 2,100 as pilot in command; 218 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 15,061 hours
- Last inspection: annual inspection, May 14, 1997; 12 hours since
- Maximum gross weight: 7,000 lb
- Seats: 2
- Landing gear: retractable
- Engine: Lycoming T10-540-32BD (piston); 0 hours total
The flight
- Departed from: BFF Scottsbluff NE at 10:30 pm
- Destination: COS Colo Springs CO
- Flight plan: IFR
- Runway 0
Weather at the time
- Light: dusk
- Sky: not recorded; not recorded
- Temperature: 0°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.
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.