Helio H-250 accident near Iliamna, Alaska, February 1, 1984
On February 1, 1984 at about 8:25 pm local time, a Helio H-250, registered N5966X, was substantially damaged in an accident near Iliamna, Alaska (Iliamna airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. 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
- February 1, 1984 · about 8:25 pm local time
- Place
- Iliamna, Alaska · Iliamna · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Helio H-250 · all H-250s on the register
- Registration
- N5966X · no longer on the register · serial 2529
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
ACCORDING TO WITNESSES, THE SKI EQUIPPED ACFT TOOK OFF TOWARD THE NORTH. THEY REPORTED THAT AFTER TAKING OFF, THE ACFT MADE A TIGHT LEFT TURN, THEN SPIRALED TO THE GROUND. THEY ESTIMATED THAT THE MAXIMUM ALT WAS APRX 150 FT. ALSO, THEY REPORTED THAT THE ENG WAS DEVELOPING FULL POWER UNTIL THE TIME OF IMPACT. THE 1229 ADT WINDS WERE FROM 010 DEG AT 19 GUSTING 27 KTS.
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
- Medical certificate: Class 2 (expired)
- Seat: left
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 3,400 lb
- Seats: 6
- Landing gear: fixed
- Engine: Lycoming O-540-A1A5 (piston); 0 hours total
The flight
- Destination: 5NN Nondalton AK
- Flight plan: none
- Runway 35, 4,800 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 010° at 19 knots, gusting 27
- Visibility: 25 statute miles
- Sky: overcast at 3,000 ft; not recorded at 3,000 ft
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
- Observation at 9:29 pm from ILI
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.