Mitsubishi MU-2B incident near Tyndall Afb, Florida, July 2, 1990
On July 2, 1990 at about 7:00 pm local time, a Mitsubishi MU-2B, registered N722DM, suffered minor damage in an incident near Tyndall Afb, Florida (Tyndall Afb airport). It was an other work-use 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
A PROPELLER BLADE FATIGUE FAILURE DUE TO IMPROPER OVERHAUL BY OTHER MAINTENANCE PERSONNEL NOT PERFORMING OVERHAUL IN ACCORDANCE WITH FACTORY SERVICE BULLETINS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 2, 1990 · about 7:00 pm local time
- Place
- Tyndall Afb, Florida · Tyndall Afb · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mitsubishi MU-2B · all MU-2Bs on the register
- Registration
- N722DM · registry record · serial 245
- Damage
- Minor damage
- Flight
- Other work-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT NOTED A SEVERE VIBRATION IN FLIGHT FROM THE LEFT ENGINE. HE SHUT THE ENGINE DOWN AND LANDED. ONE PROPELLER BLADE WAS MISSING PART OF THE BLADE. THE FAILED ASSEMBLY WAS EXAMINED AND THE FAILED BLADE SHOWED EVIDENCE OF HIGH CYCLE, LOW STREES FATIGUE WITH A SURFACE ORIGIN. THE OTHER TWO BLADES WERE FOUND TO BE LESS THAN MINIMUM DIMENSIONS AND HAD IMPROPERLY POLISHED AND PROTECTED SURFACES.
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: multi-engine land; single-engine land; instrument: airplane
- Flight time: 6,641 hours in all; 1,533 in this make and model; 143 in the last 90 days; 39 in the last 30 days; 6,441 as pilot in command
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 7,059 hours
- Last inspection: approved inspection programme, March 21, 1990; 97 hours since
- Maximum gross weight: 9,920 lb
- Seats: 3
- Landing gear: retractable
- Engine: Garrett TPE-331-251 (turboprop); 0 hours total
- Operator: Flight International
The flight
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 110° at 10 knots
- Visibility: 7 statute miles
- Sky: scat at 4,500 ft
- Temperature: 82°F (28°C), dew point 64°F (18°C)
- Altimeter: 29.00 inHg
- Observation at 4:55 pm from PAM, 5 miles away
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.