Eurocopter AS-350D N5771L
24 October 1994 · Kaupo, Hawaii, United States · Minor injuries
Summary
On 24 October 1994 at about 18:30 local time, a Eurocopter AS-350D registered N5771L was involved in an accident near Kaupo, Hawaii, United States. 4 people were on board and 4 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.
The record
- Date
- at 18:30
- Classification
- Accident
- Location
- Kaupo, Hawaii, United States
- Coordinates
- 20.7698, -155.9901
- Aircraft
- Eurocopter AS-350D
- Registration
- N5771L
- Category
- Helicopter
- Engines
- 1
- Operator
- Not recorded
- Operating rule
- Part 135: Air Taxi & Commuter
- Purpose of flight
- Unknown
- Phase of flight
- Not recorded
- Route
- Kahului → Unknown
- Aircraft damage
- Substantial
- Weather
- VMC
- Light
- Day
- NTSB number
- LAX95LA019
People
4 people had minor injuries.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 4 | 0 | 0 | 4 | 0 |
Probable cause
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.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
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.
Quoted verbatim from the NTSB record.
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 4 Nov 1994 | Piper PA-28-140 | Honolulu, Hawaii, United States | David Michael Goff | Fatal | 2 |
| 13 Feb 1994 | Schweizer 2-33-A | Dillingham, Hawaii, United States | Soar Hawaii, Ltd. | No injuries | - |
| 24 Feb 1994 | Aerospatiale AS-350-B | Humuula, Hawaii, United States | Papillon Hawaiian Helicopters | Serious injuries | - |
| 16 Oct 1994 | Beechcraft C-23 | Kahului, Hawaii, United States | - | No injuries | - |
| 26 Mar 1994 | Hughes 369D | Hi. Nat'l Park, Hawaii, United States | Mauna KEA Helicopters | Minor injuries | - |
| 17 Apr 1994 | Pitts S-2A | Kahuku, Hawaii, United States | Tsunami Aviation Hawaii, Inc | Fatal | 1 |