ASN Wikibase Occurrence # 387407
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.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Wednesday 23 August 2000 |
| Time: | 18:00 LT |
| Type: |  Bell 206BII |
| Owner/operator: | D & E Storage |
| Registration: | N90307 |
| MSN: | 1747 |
| Year of manufacture: | 1975 |
| Engine model: | Allison 250-C20 |
| Fatalities: | Fatalities: 0 / Occupants: 1 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Newhalem, WA -
 United States of America
|
| Phase: | Standing |
| Nature: | Executive |
| Departure airport: | Brewster, WA (S97) |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The pilot reported that after landing the helicopter and reducing the engine to idle power, he heard a 'snap' or 'click' above and behind him. The main rotor immediately pitched back and to the left. This violent gyration resulted in the toe of the skids to lift off the ground and the helicopter moved backwards with each pitch up. The pilot shut the engine down. The main rotors windmilled to a stop and the mast came to rest back and to the left about 30 degrees off of vertical. Inspection of the helicopter found that the pylon isolation mount failed. Examination of the mount found that the failure occurred over a long period of time and was probably due to inadequate surface preparation of the center plate to the elastomeric blocks, which resulted in the debonding of the material and allowing the center plate more movement than normal.
Probable Cause: Debonding between the elastomeric material and the center plate of the transmission isolation mount.
Accident investigation:
 |
|
Sources:
NTSB SEA00LA197
History of this aircraft
Other occurrences involving this aircraft
| 28 May 1991 | N90307 | D & E Storage | 0 | Brewster, WA | |
sub |
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 03-May-2024 08:36 | ASN Update Bot | Added |
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:
©2024 Flight Safety Foundation