Bell UH-1B accident near Juneau, Alaska, June 11, 1985
On June 11, 1985 at about 8:00 pm local time, a Bell UH-1B (helicopter), registered N99676, was destroyed in an accident near Juneau, Alaska. It was an other work-use flight under external-load helicopter rules (Part 133). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 11, 1985 · about 8:00 pm local time
- Place
- Juneau, Alaska
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell UH-1B · all UH-1Bs on the register
- Registration
- N99676 · registry record · serial 63-8513
- Damage
- Destroyed
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
WHILE ENGAGED IN A LOG SLINGING OPERATION OVER MOUNTAINOUS, DENSELY FORESTED TERRAIN THE ROTOR CRAFT SUFFERED A TOTAL POWER LOSS FORCING THE PILOT TO EXECUTE AN AUTOROTATIVE LANDING INTO HIGH CONIFER TREES. DISASSEMBLY OF THE ENGINE REVEALED EVIDENCE THAT THE SPACER BETWEEN THE NO. 5 COMPRESSOR AND THE IMPELLER HAD NOT BEEN POSITION SEATED DURING THE LAST OVERHAUL AND THAT DURING THE ACCIDENT FLIGHT THE SPACER SLIPPED INTO ITS PROPER POSITION THUS RELEASING THE COMPRESSIVE TORQUE LOAD UNDER WHICH THE ASSEMBLY HAD BEEN SUFJECTED DURING BUILDIP. THE COMPRESSOR ASSEMBLY SUBSEQUENTLY BECAME UNCOUPLED FORCING THE IMPELLER FORWARD INTO ITS MAGNESIUM HOUSING. THIS ACTION RESULTED IN AN OVERTEMPERATURE CONDITION AND BREAKUP WITHIN THE TURBINE ASSEMBLY BROUGHT ON BY THE COMBUSTION OF MAGNESIUM PARTICLES.
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: rotorcraft: helicopter
- Flight time: 3,914 hours in all; 2,100 in this make and model; 3,485 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 5,043 hours
- Last inspection: annual inspection, April 17, 1985; 62 hours since
- Maximum gross weight: 8,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming T53-L-11 (turboshaft); 0 hours total
The flight
- Departed from: JNU Juneau AK at 10:00 am
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 060° at 14 knots
- Visibility: 14 statute miles
- Sky: overcast at 3,000 ft; scat at 1,500 ft
- Temperature: 52°F (11°C), dew point 46°F (8°C)
- Altimeter: 29.00 inHg
- Observation at 3:47 pm from FNR, 13 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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 N99676 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.