Hughes 369E accident near Hanalei, Hawaii, December 12, 1988
On December 12, 1988 at about 10:48 pm local time, a Hughes 369E (helicopter), registered N7733H, was substantially damaged in an accident near Hanalei, Hawaii. It was a business flight under general aviation rules (Part 91). No one was hurt; 5 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
- December 12, 1988 · about 10:48 pm local time
- Place
- Hanalei, Hawaii · map
- Type
- Accident
- Injuries
- No one was hurt; 5 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 369E · all 369Es on the register
- Registration
- N7733H · no longer on the register · serial 0168E
- Damage
- Substantial damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
DURING A LOCAL SIGHTSEEING FLIGHT, THE PILOT REPORTED THAT HE HEARD A MUFFLED BANG AND SIMULTANEOUSLY THE ENGINE OUT WARNING LIGHTS AND AUDIO ALARM ACTIVATED. THE PILOT INITIATED A FORCED LANDING ON THE BEACH WHICH RESULTED IN THE HELICOPTER NOSING OVER. AN ENGINE EXAM REVEALED THAT THE GAS GENERATOR TURBINE HAD FAILED. THE EVIDENCE INDICATED THAT THE FAILURE WAS DUE TO CONSTANT TURBINE OVERTEMPERATURES. THE EXHAUST TEMPERATURE PROBE SYSTEM WAS TESTED AND SHOWED CONSISTENT READINGS 50 TO 100 DEGREES LOWER THAN THE ACTUAL TEMP. ADDITIONALLY, THE LIGHTOFF FUEL FLOW WAS EXCESSIVE DUE TO THE IMPROPER SETTING OF THE START/ACCELERATOR SCHEDULE ADJUSTER. MAINTENANCE RECORDS DID NOT INDICATE A RECENT EXHAUST TEMP CHECK.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: helicopter; instrument: airplane; rotorcraft: helicopter
- Flight time: 4,673 hours in all; 693 in this make and model; 360 in the last 90 days; 115 in the last 30 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 5,666 hours
- Last inspection: inspection type not recorded, November 18, 1988; 92 hours since
- Maximum gross weight: 3,000 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
The flight
- Departed from: Lihue HI at 10:15 pm
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 070° at 5 knots
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 4 |
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.