Mitsubishi MU-2B-60 accident near Rapid City, South Dakota, February 9, 1990
On February 9, 1990 at about 6:14 pm local time, a Mitsubishi MU-2B-60, registered N64MD, was substantially damaged in an accident near Rapid City, South Dakota (Rapid City Regional airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 1 person was killed, 1 person was seriously injured and 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FAILURE OF THE PILOT TO MAINTAIN ADEQUATE AIRSPEED (VMC), WHICH RESULTED IN A LOSS OF AIRCRAFT CONTROL. A FACTOR RELATED TO THE ACCIDENT WAS: FATIGUE FAILURE OF A COUPLING SHAFT IN THE #1 ENGINE, WHICH RESULTED IN LOSS OF POWER IN THAT ENGINE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 9, 1990 · about 6:14 pm local time
- Place
- Rapid City, South Dakota · Rapid City Regional · map
- Type
- Accident
- Injuries
- 1 person was killed, 1 person was seriously injured and 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Mitsubishi MU-2B-60 · all MU-2B-60s on the register
- Registration
- N64MD · no longer on the register · serial 747SA
- 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
WITNESSES RPRTD THAT SHORTLY AFTER LIFT-OFF, THE ACFT ENTERED AN UNUSUALLY STEEP, NOSE HIGH ATTITUDE, WHILE STILL AT LOW AIRSPEED. ONE WITNESS (AN ATP PLT) RPRTD THE ACFT ATTAINED AN ALT OF APRX 75 TO 100 FT AND APPEARED TO SLOW DOWN AND ENTER A VMC ROLL, THEN IT CRASHED. IMPACT OCCURRED IN AN INVERTED, NOSE DOWN ATTITUDE, LEFT OF THE RWY. AN INVESTIGATION REVEALED THAT A COUPLING SHAFT (PN 865888-3) HAD FAILED IN THE LEFT ENG & THE LEFT PROP HAD FEATHERED. A METALLURICAL EXAM OF THE COUPLING SHOWED EVIDENCE OF FATIGUE.
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, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 5,985 hours in all; 291 in this make and model; 140 in the last 90 days; 53 in the last 30 days; 4,185 as pilot in command
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 4,382 hours
- Last inspection: approved inspection programme, February 4, 1990; 14 hours since
- Maximum gross weight: 11,575 lb
- Seats: 7
- Landing gear: retractable
- Engine: Garrett TPE-331-10 (turboprop); 0 hours total
- Fire on the ground
- Operator: Aeromedical Services Intl
The flight
- Departed from: RAP at 6:13 pm
- Destination: CYWG Manitoba,Canada OF
- Flight plan: VFR then IFR
- Runway 14, 8,701 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 170° at 14 knots
- Visibility: 35 statute miles
- Sky: broken clouds at 7,000 ft; scat at 4,000 ft
- Temperature: 32°F (0°C), dew point 18°F (-8°C)
- Altimeter: 29.00 inHg
- Observation at 6:16 pm from RAP, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | 1 | ||
| Passengers | 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.