ASN Wikibase Occurrence # 287074
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 7 April 2009 |
| Time: | 14:30 LT |
| Type: |  Sikorsky CH-54B |
| Owner/operator: | Helicopter Transport Services, Inc. |
| Registration: | N719HT |
| MSN: | 69-18469 |
| Year of manufacture: | 1970 |
| Total airframe hrs: | 5365 hours |
| Engine model: | P & W JFTD12A-5A |
| Fatalities: | Fatalities: 0 / Occupants: 2 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Corvallis, Oregon -
 United States of America
|
| Phase: | Standing |
| Nature: | Training |
| Departure airport: | Corvallis, OR |
| Corvallis, OR | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The pilot and certified flight instructor departed for a local area instructional flight during which the pilot practiced a series of takeoffs and landings. During ground operations, the crew stated that they felt an unusual vibration, which was partially mitigated by keeping the collective pitch raised about 2 inches from the full down position. The pilot reported that he decided to adjust his seat position so he landed and handed off the controls to the certified flight instructor (CFI). The CFI lowered the collective to the full down position in preparation for the seat adjustment operation. At this time he noticed a vibration, which was followed by a loud "bang." The subsequent helicopter examination revealed that two of the six main rotor blades had diverged from their normal plane of rotation and impacted the tail rotor drive system, resulting in the number 5 and 6 tail rotor drive shaft sections separating from the helicopter. The investigation and examination of the helicopter found that during maintenance performed at an undetermined date by the operator's mechanics, the bell cranks that connect to the main rotor blades' control rods had been incorrectly installed in a reversed manner. This allowed the swash plate to travel outside of its designed range.
Probable Cause: The improper assembly of main rotor blade control components by the operator's maintenance personnel, which resulted in the main rotor blade's divergent path and their contact with the tail rotor drive shaft during ground operation following landing.
Accident investigation:
 |
|
Sources:
NTSB WPR09LA184
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 04-Oct-2022 07:00 | 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