ASN Wikibase Occurrence # 299154
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: | Thursday 6 April 2000 |
Time: | 07:00 LT |
Type: | RotorWay Exec 162F |
Owner/operator: | Cobb International |
Registration: | N21901 |
MSN: | RI6035 |
Fatalities: | Fatalities: 0 / Occupants: 2 |
Aircraft damage: | Substantial |
Category: | Accident |
Location: | CHANDLER, Arizona -
United States of America
|
Phase: | Unknown |
Nature: | Training |
Departure airport: | , AZ (P19) |
Destination airport: | |
Investigating agency: | NTSB |
Confidence Rating: | Accident investigation report completed and information captured |
Narrative:The helicopter landed hard collapsing the left skid and resulting in the main rotor blades striking the tail boom. While in the traffic pattern, during the downwind leg, the pilot heard a loud noise from the rear of the helicopter. He entered an autorotation and checked the cockpit instruments. Noting no anomalies, he rolled on the throttle and discovered that the engine speed would increase but the rotor speed would not. The pilot flared to avoid a fence then landed hard. Subsequent examination of the engine secondary shaft that transmits power to the main rotor through drive belts revealed that the shaft had failed in fatigue. There were numerous longitudinal and circumferential score marks on the secondary shaft indicating removal and reinstallation of the shaft many times. The fatigue fracture originated at one of the circumferential score marks and exhibited oxidation, indicating it had been fractured for some time.
Probable Cause: The inadequate maintenance inspection of the secondary shaft which resulted in its fatigue failure that emanated from a corroded circumferential score mark. A factor was the fence that the pilot flared to avoid, resulting in a hard landing.
Accident investigation:
|
| |
Investigating agency: | NTSB |
Report number: | |
Status: | Investigation completed |
Duration: | 1 year and 6 months |
Download report: | Final report |
|
Sources:
NTSB LAX00LA173
Revision history:
Date/time | Contributor | Updates |
16-Oct-2022 03:11 |
ASN Update Bot |
Added |
The Aviation Safety Network is an exclusive service provided by:
CONNECT WITH US:
©2024 Flight Safety Foundation