Beech B200 incident near Greenbay, Wisconsin, July 22, 1991
On July 22, 1991 at about 2:05 pm local time, a Beech B200, registered N770M, suffered minor damage in an incident near Greenbay, Wisconsin. It was a business flight under general aviation rules (Part 91). No one was hurt; 8 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
INADEQUATE AIRFRAME DESIGN, WHICH RESULTED IN THE IN-FLIGHT SEPARATION OF THE LEFT ENGINE'S OUTBOARD AFT UPPER COWL DOOR.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 22, 1991 · about 2:05 pm local time
- Place
- Greenbay, Wisconsin · map
- Type
- Incident
- Injuries
- No one was hurt; 8 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech B200 · all B200s on the register
- Registration
- N770M · no longer on the register · serial BB1330
- Damage
- Minor damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE TWIN-ENGINE TURBO PROP AIRPLANE WAS CRUISING AT 8000' MSL, WHEN THE LEFT ENGINE'S OUTBOARD AFT UPPER ACCESSORY CASE COWL DOOR SEPARTED FROM ITS MOUNT. THE COWL DOOR STRUCK THE TOP SURFACE OF THE LEFT WING (OUTBOARD OF THE ENGINE NACELLE) & PENETRATED THE WING'S FUEL CELL. THIS RESULTED IN FUEL SIPHONING & PROMPTED THE PILOT TO PERFORM A PRECAUTIONARY ENGINE SHUTDOWN. THE AIRPLANE WAS LANDED WITHOUT FURTHER INCIDENT. AIRWORTHINESS DIRECTIVE (AD) 91-18-11 (EFFECTIVE 9/3/91) REQUIRED STRUCTURAL MODIFICATION OF THE AFT UPPER COWL ASSEMBLY DOORS TO PREVENT INFLIGHT SEPARATION.
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; instrument: airplane
- Flight time: 6,800 hours in all; 1,800 in this make and model
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 12,500 lb
- Seats: 8
- Landing gear: retractable
- Engine: P&W PT6A-42 (turboprop); 0 hours total
The flight
- Departed from: MKE Milwaukee WI at 1:35 pm
- Destination: GRB Greenbay WI
- Flight plan: IFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 240° at 7 knots
- Visibility: 3 statute miles
- Sky: broken clouds at 8,000 ft; scat at 700 ft
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 1:50 pm from GRB, 35 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 | |||
| Passengers | 6 |
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.