Eurocopter AS-350D accident near Kaupo, Hawaii, October 24, 1994
On October 24, 1994 at about 6:30 pm local time, a Eurocopter AS-350D (helicopter), registered N5771L, was substantially damaged in an accident near Kaupo, Hawaii. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 4 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
a total loss of engine power by the corrosion fatigue failure of the compressor impeller due to the failure of company maintenance personnel to perform the prescribed daily compressor wash procedures and the inadequate maintenance inspections, which failed to detect the corrosion and subsequent pitting, that led to the fatigue initiation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 24, 1994 · about 6:30 pm local time
- Place
- Kaupo, Hawaii · map
- Type
- Accident
- Injuries
- 4 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Eurocopter AS-350D · all AS-350Ds on the register
- Registration
- N5771L · registry record · serial 1343
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
AN EUROCOPTER AS-350D COLLIDED WITH TREES AFTER A LOSS OF POWER WHILE OPERATING IN A MARINE ENVIRONMENT. THE PILOT REPORTED HE HEARD AN EXPLOSION FOLLOWED BY THE ENGINE OUT HORN. THE ENGINE TEMPERATURE (T4) GAUGE WAS NOTED AT 900 DEGREES CELSIUS AND THE ENGINE CHIP DETECTOR LIGHT ILLUMINATED. EXAMINATION REVEALED THAT THE ENGINE HAD SUSTAINED DAMAGE TO THE AXIAL COMPRESSOR, COMPRESSOR STATOR VANES, AND THE IMPELLER. PORTIONS OF THE IMPELLER BLADES WERE EXAMINED MICROSCOPICALLY REVEALING EVIDENCE OF METAL FATIGUE, WITH PITTING EVIDENT THROUGHOUT THE BLADES. ENERGY DISPERSIVE X RAY SHOWED THE PRESENCE OF SULFUR AND CHLORINE IN CORROSION DEPOSITS IN THE PITS. THE ENGINE WAS INSPECTED TWICE IN THE MONTH PRECEDING THE ACCIDENT. THE INSPECTION CRITERIA OUTLINED IN THE ENGINE MAINTENANCE MANUAL DETAILS A VISUAL INSPECTION PROCEDURE OF THE COMPRESSOR SECTION FOR CRACKS. THE MAINTENANCE MANUAL ALSO PRESCRIBES A DAILY COMPRESSOR WATER RINSE TO REMOVE SALT DEPOSITS, FOLLOWED BY INSPECTING THE COMPRESSOR FOR CLEANLINESS.
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: instructor: helicopter; rotorcraft: helicopter
- Flight time: 3,216 hours in all; 2,100 in this make and model; 236 in the last 90 days; 96 in the last 30 days; 3,150 as pilot in command; 642 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 9,146 hours
- Last inspection: annual inspection, October 12, 1994; 53 hours since
- Maximum gross weight: 4,300 lb
- Seats: 7
- Landing gear: fixed
- Engine: Lycoming LTS-101-600A3 (turboshaft); 0 hours total
The flight
- Departed from: OGG Kahului HI at 6:00 pm
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 040° at 7 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 63°F (17°C)
- Altimeter: 29.00 inHg
- Observation at 5:54 pm from OGG, 28 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 3 |
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 N5771L 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.