Hughes 369D accident near Nunavaugaluk Lk, Alaska, September 9, 1992
On September 9, 1992 at about 6:10 pm local time, a Hughes 369D (helicopter), registered N8697F, was substantially damaged in an accident near Nunavaugaluk Lk, Alaska. It was a business flight under general aviation rules (Part 91). 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE SEPARATION OF THE TAIL ROTOR ABRASION STRIP AND THE SUBSEQUENT TOTAL LOSS OF THE TAIL ROTOR. FACTORS CONTRIBUTING TO THE ACCIDENT WERE: INSUFFICIENT MANUFACTURER'S MAINTENANCE DESIGN CHANGES, INADEQUATE AIRCRAFT EQUIPMENT DESIGN BY THE MANUFACTURER AND INSUFFICIENT STANDARDS OF THE FAA CERTIFICATION ORGANIZATION.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 9, 1992 · about 6:10 pm local time
- Place
- Nunavaugaluk Lk, Alaska · map
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 369D · all 369Ds on the register
- Registration
- N8697F · no longer on the register · serial 1170221D
- Damage
- Substantial damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
SHORTLY AFTER TAKEOFF, AT 1,000 FT AGL, THE PILOT EXPERIENCED AIRFRAME VIBRATION AND A GRINDING SOUND. HE ENTERED AUTOROTATION, AND AT 200 FT AGL THE TAIL ROTOR AND PART OF THE T/R GEAR BOX SEPARATED FROM THE HELICOPTER. IT THEN ROTATED APPROXIMATELY 720 DEG AND IMPACTED THE GROUND. ONE OF THE T/R BLADES WAS MISSING THE ABRASION STRIP. AN AIRWORTHINESS DIRECTIVE (AD) & SERVICE BULLETIN (SB) WERE IN EFFECT DIRECTING INSTALLATION OF RIVETS WITHIN 300 HRS TO PREVENT POSSIBLE LOSS OF TAILROTOR CONTROL. DUE TO SEASONAL USE, HELICOPTER HAD LESS THAN 160 HRS SINCE ISSUANCE OF THE AD. TAIL ROTOR BLADE FOUND INTACT WAS 40% DEBONDED, BUT WOULD PASS A 'TAP TEST' IAW MANUFACTURER'S SB. FAILED BLADE ESTIMATED TO BE 90% DEBONDED. DAILY VISUAL INSPECTION REQUIRED BY SB REPORTEDLY DID NOT DETECT DEBONDING IN PROGRESS.
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: private
- Ratings: single-engine land; single-engine sea; rotorcraft: helicopter
- Flight time: 1,679 hours in all; 500 in this make and model; 150 in the last 90 days; 50 in the last 30 days; 1,400 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,527 hours
- Last inspection: annual inspection, May 16, 1992; 152 hours since
- Maximum gross weight: 3,000 lb
- Seats: 2
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: Crystal Cr Lodg AK at 12:45 pm
- Destination: Kokwok River AK
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 340° at 8 knots
- Sky: not recorded; scat at 3,500 ft
- Temperature: 45°F (7°C), dew point 34°F (1°C)
- Altimeter: 29.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
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.