Bell UH-1L accident near Wenatchee, Washington, May 31, 1986
On May 31, 1986 at about 2:10 pm local time, a Bell UH-1L (helicopter), registered N4964N, was destroyed in an accident near Wenatchee, Washington. It was a flight of an unrecorded kind 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
- May 31, 1986 · about 2:10 pm local time
- Place
- Wenatchee, Washington · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell UH-1L · all UH-1Ls on the register
- Registration
- N4964N · no longer on the register · serial 157854
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
N4964N, A BELL UH-1L, WAS BEING OPERATED IN LOGGING OPS BY AN EXPERIENCED, MILITARY TRAINED PLT WHO POSSESSED 6000 HRS OF FLT EXPERIENCE IN MODEL. WHILE LIFTING A SLING LOAD GND CREW RPTD SMOKE FROM THE TAIL ROTOR AREA. PLT RELEASED SLING LOAD & ACKNOWLEDGED THE WARNING RADIOING HIS INTENTIONS TO LAND NEARBY. THE SUBSEQUENT LOSS OF TAIL ROTOR/DIRECTNL CNTRL PLACED ROTORCRAFT IN A CONDITION WHEREBY AN AUTOROTATION WAS NOT POSSBL & A RUN ON LNDG WAS NECESSARY. UNSUITABLE TERRAIN LEFT THE PLT WITH ONLY TWO FORCED LNDG OPTIONS, ONE ON CURVING, HILLY HWY WITH POTENTIAL FOR A COLLISION WITH AUTO TRAFFIC, OR THE OTHER INTO HEAVILY TREED TERRAIN. THE PLT APPEARS TO HAVE CHOSEN THE LATTER. IT IS NOT APPARENT WHY HE CHOSE THIS OPTION RATHER THAN DIVERTING TO A NEARBY AIRSTRIP OR SOME OTHER LEVEL FORCED LNDG AREA. THE 42 DEGREE GEARBOX, WHICH HAD BEEN OVERHAULED AND INSTALLED 195 HRS PREVIOUSLY IN ACFT, WAS FOUND TO HAVE FAILED WHEN THE INPUT PINION GEAR FRACTURED IN FATIGUE ORIGINATING FROM CORROSION.
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: multi-engine land; single-engine land; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 11,250 hours in all; 6,000 in this make and model
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 7,899 hours
- Last inspection: 100-hour inspection, May 18, 1986; 41 hours since
- Maximum gross weight: 9,500 lb
- Seats: 7
- Landing gear: fixed
- Engine: Lycoming T53-L13B (turboshaft); 0 hours total
- Fire on the ground
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 260° at 8 knots
- Visibility: 30 statute miles
- Sky: clear
- Temperature: 66°F (19°C), dew point 52°F (11°C)
- Altimeter: 29.00 inHg
- Observation at 1:52 pm from EAT, 15 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.
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.