ASN Wikibase Occurrence # 42442
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: | Friday 4 October 1996 |
| Time: | 13:15 LT |
| Type: |  Boeing Vertol 107-II (CH-46A) |
| Owner/operator: | Columbia Helicopters, Inc. |
| Registration: | N196CH |
| MSN: | 407 |
| Year of manufacture: | 1965 |
| Total airframe hrs: | 7075 hours |
| Engine model: | GE T58-140-1A |
| Fatalities: | Fatalities: 3 / Occupants: 3 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | Canby, OR -
 United States of America
|
| Phase: | En route |
| Nature: | Unknown |
| Departure airport: | Aurora, OR (3S2) |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The Boeing Model BV-107-II departed on a maintenance check flight with 1.4 hrs total flight time after conversion from a Model HKP-4 per FAA Project #TDO639NY-R. About 37 min later, witnesses saw the rotorcraft moving erratically & tumbling out of control. Postcrash exam of the rotorcraft's flight control system revealed a disconnect between the lower bearing end of the aft directional and lateral control pushrod & the inboard clevis of the forward mixing unit section bellcrank. A bolt, consistent with hardware for that connection, was found in the control closet area. An improper part (collective bellcrank, PN 107C2606-8) was found in place of the required lateral bellcrank (PN 107C2606-9). Clevis width of the -8 part was slightly larger than the -9 part; thus, the clevis bolt was not long enough to allow a cotter pin to be properly installed through the nut & bolt with the required washers (2 thick & 1 thin) installed. To compensate (allow for installation of the cotter pin), 2 thin washers were used in place of the 2 thick and 1 thin washers. Metallurgical exam of the bolt revealed evidence that a nut had been applied to the threaded end, but there was no evidence that a cotter pin had been inserted. No pre-accident engine malfunction or crew impairment was evident.
Probable Cause: failure of maintenance personnel to install a cotter pin in a clevis bolt in the flight control system, which resulted in the aft directional and lateral control output pushrod to become disconnected from a bellcrank in the forward portion of the first stage mixing unit. A factor relating to the accident was the use of an improper bellcrank, which was wider in the clevis area.
Accident investigation:
 |
|
Sources:
NTSB SEA97FA001
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 24-Oct-2008 10:30 | ASN archive | Added |
| 10-Jan-2011 07:18 | TB | Updated [Time, Aircraft type, Other fatalities, Nature, Source] |
| 21-Dec-2016 19:24 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 08-Apr-2024 18:46 | ASN Update Bot | Updated [Time, Operator, Other fatalities, Nature, Source, Narrative, Category, Accident report] |
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