Bell 206 B3 accident near Teterboro, New Jersey, July 10, 1990
On July 10, 1990 at about 8:59 pm local time, a Bell 206 B3 (helicopter), registered N73LM, was substantially damaged in an accident near Teterboro, New Jersey (Teterboro airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FAILED POWER TURBINE SHAFT. FACTORS IN THE ACCIDENT WERE CORROSION ON THE POWER TURBINE SHAFT AND INADEQUATE MANUFACTURER'S SERVICE BULLETINS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 10, 1990 · about 8:59 pm local time
- Place
- Teterboro, New Jersey · Teterboro
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206 B3 · all 206 B3s on the register
- Registration
- N73LM · registry record · serial 2835
- 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
THE PILOT WAS HOVERING WHEN HE HEARD A WHINE IN THE ENGINE THAT INCREASED IN INTENSITY. HE SAW TORQUE FLUCTUATIONS, HEARD AN EXPLOSION, AND AUTOROTATED TO THE RAMP. INVESTIGATION SHOWED THE POWER TURBINE INNER SHAFT FAILED IN TORSION DUE TO CORROSION ON THE INNER SURFACE AND THIS ALLOWED THE THIRD STAGE TURBINE WHEEL TO GO INTO OVERSPEED AND FAIL. ALLISON ISSUED THREE SERVICE BULLETINS ON THE POWER TURBINE INNER SHAFT. NONE OF THEM USED CALENDAR TIME FOR COMPLIANCE, ONLY ENGINE TOTAL TIME. THE HELICOPTER WAS 11 YEARS OLD WITH 2146 HRS TT AIRFRAME AND ENGINE. THE FIRST SCHEDULED WORK ON THE POWER TURBINE OCCURS AT 3550 HRS.
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: single-engine land; instructor: airplane single-engine; instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 3,458 hours in all; 3,000 in this make and model; 74 in the last 90 days; 47 in the last 30 days; 3,176 as pilot in command; 500 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,146 hours
- Last inspection: 100-hour inspection, June 28, 1990; 19 hours since
- Maximum gross weight: 3,200 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
- Operator: Annapolis Aviation
The flight
- Departed from: TEB
- Destination: BWI Baltimore MD
- Flight plan: VFR
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 300° at 10 knots
- Visibility: 15 statute miles
- Sky: broken clouds at 10,000 ft; scat at 3,000 ft
- Temperature: 84°F (29°C), dew point 63°F (17°C)
- Altimeter: 29.00 inHg
- Observation at 8:50 pm from TEB
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.