This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
You can contribute by submitting additional or updated information.
| Date: | Monday 11 July 1983 |
| Time: | 16:23 |
| Type: |  Aérospatiale AS 350D |
| Owner/operator: | Era Helicopters Inc |
| Registration: | N141EH |
| MSN: | 1460 |
| Total airframe hrs: | 813 hours |
| Engine model: | Lycoming LTS-101-600A2 |
| Fatalities: | Fatalities: 0 / Occupants: 4 |
| Other fatalities: | 0 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | Unalaska Airport, Dutch Harbor, Amaknak Island, Aleutians, AK -
 United States of America
|
| Phase: | Landing |
| Nature: | External load operation |
| Departure airport: | Unalaska Airport, Alaska (DUT/PADU) |
| Unalaska Airport, Alaska (DUT/PADU) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Information is only available from news, social media or unofficial sources |
APPROXIMATELY 2 MINUTES AFTER TAKEOFF, THE PILOT & PASSENGERS HEARD A LOUD MUFFLED BOOM FROM BEHIND THE FIREWALL, THEN THE ROTOR RPM BEGAN TO DECAY. THE PILOT ENTERED AN AUTOROTATION & SELECTED A LANDING AREA. HE NOTED THAT THE ENGINE WAS NOT DRIVING THE ROTOR SYSTEM, SO HE SHUT IT DOWN TO REDUCE THE POSSIBILITY OF FIRE WHILE LANDING. DURING AN EMERGENCY LANDING ON SLOPING, MOUNTAINOUS TERRAIN, THE HELICOPTER ROLLED OVER, AND SUBSEQUENTLY, IT CAME TO REST IN A RAVINE AT THE BOTTOM OF THE SLOPE. Human occupants survived. A camp dog riding inside the helicopter died in the incident. The crash site was on the lower slopes of Makushin Volcano, located 20-30 minutes helicopter flight time from Dutch Harbor. At the time of the engine failure, N141EH was slinging drilling equipment and would be expected (not confirmed, just "usual procedure") to be lifting at close to or slightly beyond maximum rated power.
A TEARDOWN OF THE ENG REVEALED THAT THE #3 BEARING, PN 4-301-051-02, HAD FAILED & THAT THE OIL JET FOR THE BEARING WAS CLOGGED. REPORTEDLY, MAINTENANCE PERSONNEL WERE AWARE THAT A DIFFERENTIAL PRESSURE CHECK, TO DETECT CLOGGING TO THE #2 & #3 PACKAGED OIL JETS, WAS 7 TO 8 PSI. THIS WAS 2 TO 3 PSI TOO HIGH & INDICATED CLOGGING OF THE OIL JETS. (THIS PROCEDURE WAS OUTLINED IN LYCOMING SVC BULLETIN LTS101A-17-0014). HOWEVER, THE DISCREPANCY WAS NOT ENTERED IN THE ENG MAINTENANCE LOGS.
Accident investigation:
 |
|
Sources:
1, NTSB: https://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001214X43555&key=1
2. FAA: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?omni=Home-N-Number&nNumberTxt=141EH
3. https://www.helis.com/database/cn/34963/
4. http://www.griffin-helicopters.co.uk/accidentdetails.aspx?accidentkey=11583
5. https://en.wikipedia.org/wiki/Unalaska_Airport
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 27-Jun-2014 19:16 | Dr. John Smith | Updated [Location, Nature, Departure airport, Destination airport, Source, Narrative, ] |
| 21-Dec-2016 19:26 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency, ] |
| 17-Jun-2023 05:45 | Ron Averes | Updated |
| 08-Apr-2025 07:05 | Greg | Updated [Narrative, ] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2025 Flight Safety Foundation