Hughes 500-D accident near Seattle, Washington, October 10, 1986
On October 10, 1986 at about 3:50 pm local time, a Hughes 500-D (helicopter), registered N58239, was substantially damaged in an accident near Seattle, Washington (Boeing Field). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. 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
- October 10, 1986 · about 3:50 pm local time
- Place
- Seattle, Washington · Boeing Field · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 500-D
- Registration
- N58239 · no longer on the register · serial 1280392D
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
DURING A PRACTICE AUTOROTATION A LOSS OF POWER OCCURRED. THE PILOT ATTEMPTED ENGINE RECOVERY BUT WAS UNABLE TO RESULTING IN A HARD LANDING IN WHICH THE MAIN ROTOR BLADE FLEXED, SEVERING THE TAIL BOOM. THE THROTTLE LINKAGE ON THE PILOTS SIDE WAS FOUND TO HAVE BEEN OUT OF ADJUSTMENT, CAUSING THE ENGINE POWER TO FALL BELOW IDLE.
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, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 4,500 hours in all; 1,000 in this make and model; 100 in the last 90 days; 4,200 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 3,000 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: BFI Seattle WA at 3:45 pm
- Flight plan: none
- Runway 31L, 10,000 ft by 200 ft
Weather at the time
- Light: daylight
- Wind: from 360° at 7 knots
- Visibility: 7 statute miles
- Sky: overcast; clear
- Temperature: 61°F (16°C), dew point 0°F (-18°C)
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.
Other NTSB records under N58239 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.