Hughes 369D accident near Puako, Hawaii, May 11, 1997
On May 11, 1997 at about 2:20 am local time, a Hughes 369D (helicopter), registered N5105N, was destroyed in an accident near Puako, Hawaii. It was a personal flight under general aviation rules (Part 91). 2 people were killed and 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
erosion of second stage stator vanes, inadequate maintenance inspection for the erosion, and subsequent fatigue failure of a stator vane, which resulted in loss of engine power and a forced landing on mountainous/hilly terrain. Also causal was: the pilot's loading of the aircraft in such a manner that exceeded the forward CG limit, which resulted in his failure (or inability) to properly flare the helicopter during a forced autorotation and landing. The rising terrain and tailwind condition for landing were related factors.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 11, 1997 · about 2:20 am local time
- Place
- Puako, Hawaii · map
- Type
- Accident
- Injuries
- 2 people were killed and 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Hughes 369D · all 369Ds on the register
- Registration
- N5105N · no longer on the register · serial 911055D
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The helicopter was cruising at low level when the engine failed. The pilot turned toward a landing area and entered an autorotation with a quartering tailwind. During the autorotation, the helicopter continued to descend, remaining in a nose low attitude, until striking the ground. Impact occurred on up sloping terrain, and the helicopter was damaged. A computation of the weight and balance revealed the helicopter's moment arm exceeded the forward CG limit by about one inch, and limited aft cyclic control. An examination of the engine revealed that a stator vane had failed due to excessive erosion and fatigue cracking. The condition had not been detected during a compressor case erosion inspection, 60 flight hours before the accident.
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: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 10,384 hours in all
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,800 hours
- Last inspection: annual inspection, April 1, 1997; 60 hours since
- Maximum gross weight: 3,000 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
- Fire on the ground
The flight
- Departed from: Mano Point HI at 2:05 am
- Destination: MUE Waimea-Kohala HI
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 130° at 8 knots
- Visibility: 15 statute miles
- Sky: scat at 4,000 ft
- Temperature: 82°F (28°C), dew point 64°F (18°C)
- Altimeter: 29.00 inHg
- Observation at 1:50 am from KON, 22 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 | 2 |
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.