Bell 206B-3 accident near Houston, Texas, May 7, 1991
On May 7, 1991 at about 6:10 pm local time, a Bell 206B-3 (helicopter), registered N717NH, was destroyed in an accident near Houston, Texas. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 2 people were seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
ENGINE MOUNT DELAMINATION AND LACK LUBRICATION, CAUSING THE DRIVE SHAFT TO FAIL. POOR SERVICING OF THE HELICOPTER WAS A RELATED FACTOR.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 7, 1991 · about 6:10 pm local time
- Place
- Houston, Texas · map
- Type
- Accident
- Injuries
- 2 people were seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206B-3 · all 206B-3s on the register
- Registration
- N717NH · no longer on the register · serial 2847
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
WHILE ON A FLIGHT OVER METROPOLITAN HOUSTON TO GET AERIAL VIDEO FOOTAGE, THE MAIN DRIVE SHAFT COUPLING FAILED & THE PILOT WAS FORCED TO MAKE AN AUTOROTATION. HE TRIED TO LAND IN A PARKING LOT, BUT WAS UNABLE TO REACH IT. SUBSEQUENTLY, THE HELICOPTER CRASH LANDED ON THE ROOF OF AN APARTMENT HOUSE. AN INVESTIGATION DISCLOSED THE ENGINE MOUNT WAS OIL SOAKED & HAD DELAMINATED, CAUSING MISALIGNMENT OF THE DRIVE SHAFT. ALSO, A LACK OF LUBRICATION WAS NOTED IN THE MAIN DRIVE SHAFT COUPLING. OTHER MAINTENANCE DISCREPANCIES WERE ALSO NOTED DURING THE INVESTIGATION.
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, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 8,021 hours in all; 1,415 in this make and model; 62 in the last 90 days; 15 in the last 30 days; 7,414 as pilot in command; 1,165 on instruments
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,966 hours
- Last inspection: 100-hour inspection, October 27, 1990; 98 hours since
- Maximum gross weight: 3,200 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: N/A Houston TX at 4:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 090° at 8 knots
- Visibility: 7 statute miles
- Sky: broken clouds at 1,400 ft; scat at 1,000 ft
- Temperature: 73°F (23°C), dew point 70°F (21°C)
- Altimeter: 30.00 inHg
- Observation at 6:50 pm from HOU, 9 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 | 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.
Other NTSB records under N717NH the same tail number, which may have belonged to a different aircraft at the time
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.