Mitsubishi MU-2B-20 accident near Denver, Colorado, October 12, 1986
On October 12, 1986 at about 4:51 pm local time, a Mitsubishi MU-2B-20, registered N3MU, was substantially damaged in an accident near Denver, Colorado (Stapleton Int'L airport). It was a ferry flight under general aviation rules (Part 91). No one was hurt; 2 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
- October 12, 1986 · about 4:51 pm local time
- Place
- Denver, Colorado · Stapleton Int'L · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mitsubishi MU-2B-20 · all MU-2B-20s on the register
- Registration
- N3MU · registry record · serial 143
- Damage
- Substantial damage
- Flight
- Ferry flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
ACFT HAD BEEN REPOSSESSED AND WAS BEING FERRIED FROM GRAND JUNCTION, CO, TO CHICAGO, IL, WITH EN ROUTE STOP AT DENVER, CO. AFTER TAKEOFF FROM DENVER, LANDING GEAR WOULD NOT RETRACT. PLT MADE SEVERAL ATTEMPTS WITHOUT SUCCESS. HE ELECTED TO RETURN TO DENVER. PLT SAID THAT ON FINAL APCH THE RIGHT ENG BEGAN SURGING AND THE LEFT ENG WOULD NOT INCREASE PWR. ACFT MADE HARD LANDING ON RWY, BREAKING LEFT WING. INVESTIGATION REVEALED BOTH SPEED LEVERS WOULD NOT FUNCTION BECAUSE ENG PROP GOVERNORS AND UNDERSPEED FUEL GOVERNOR RESET ARMS, SPLINED ONTO UNDERSPEED FUEL GOVERNOR SHAFTS, WERE POSITIONED ON OPPOSITE SIDE OF SPEED LEVER ACTUATING ARMS. LANDING GEAR FUNCTIONED NORMALLY DURING SWING TESTS. IT WAS LATER LEARNED THAT RIGHT MAIN TIRE HAD BLOWN ON TAKEOFF 3 DAYS EARLIER AND REQUIRED REPAIR. MAINTENANCE PERSONNEL OPENED THE LANDING GEAR CIRCUIT BREAKERS TO PRECLUDE INADVERTENT GEAR RETRACTION. PLT SAID HE CHECKED CIRCUIT BREAKERS WHEN GEAR FAILED TO RETRACT.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 4,186 hours in all; 38 in this make and model; 25 in the last 90 days; 4,050 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 5,780 hours
- Last inspection: 100-hour inspection, July 27, 1985; 100 hours since
- Maximum gross weight: 9,920 lb
- Seats: 7
- Landing gear: retractable
- Engine: Garrett TPE331-1-151A (turboprop); 0 hours total
The flight
- Destination: MDW Chicago IL
- Flight plan: IFR
- Runway 0, 10,004 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: overcast at 25,000 ft; scat at 6,000 ft
- Temperature: 32°F (0°C), dew point 18°F (-8°C)
- Altimeter: 30.00 inHg
- Observation at 4:51 pm from DEN
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.