ASN Wikibase Occurrence # 366614
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: | Tuesday 10 July 1990 |
| Time: | 16:59 LT |
| Type: |  Bell 206 B3 |
| Owner/operator: | Annapolis Aviation |
| Registration: | N73LM |
| MSN: | 2835 |
| Total airframe hrs: | 2146 hours |
| Engine model: | Allison 250-C20B |
| Fatalities: | Fatalities: 0 / Occupants: 3 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Teterboro, NJ -
 United States of America
|
| Phase: | Taxi |
| Nature: | Unknown |
| Departure airport: | (KTEB) |
| Baltimore, MD (KBWI) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
THE PILOT WAS HOVERING WHEN HE HEARD A WHINE IN THE ENGINE THAT INCREASED IN INTENSITY. HE SAW TORQUE FLUCTUATIONS, HEARD AN EXPLOSION, AND AUTOROTATED TO THE RAMP. INVESTIGATION SHOWED THE POWER TURBINE INNER SHAFT FAILED IN TORSION DUE TO CORROSION ON THE INNER SURFACE AND THIS ALLOWED THE THIRD STAGE TURBINE WHEEL TO GO INTO OVERSPEED AND FAIL. ALLISON ISSUED THREE SERVICE BULLETINS ON THE POWER TURBINE INNER SHAFT. NONE OF THEM USED CALENDAR TIME FOR COMPLIANCE, ONLY ENGINE TOTAL TIME. THE HELICOPTER WAS 11 YEARS OLD WITH 2146 HRS TT AIRFRAME AND ENGINE. THE FIRST SCHEDULED WORK ON THE POWER TURBINE OCCURS AT 3550 HRS.
Probable Cause: FAILED POWER TURBINE SHAFT. FACTORS IN THE ACCIDENT WERE CORROSION ON THE POWER TURBINE SHAFT AND INADEQUATE MANUFACTURER'S SERVICE BULLETINS.
Accident investigation:
 |
|
Sources:
NTSB NYC90FA156
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 21-Mar-2024 10:18 | 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