ASN Wikibase Occurrence # 201906
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: | Sunday 24 January 1999 |
| Time: | 10:00 LT |
| Type: |  Hiller UH-12E |
| Owner/operator: | Breen Aviation, Inc. |
| Registration: | N67064 |
| MSN: | 1355 |
| Total airframe hrs: | 8029 hours |
| Engine model: | Lycoming VO-540-C2A |
| Fatalities: | Fatalities: 0 / Occupants: 1 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | Lemoore, CA -
 United States of America
|
| Phase: | Manoeuvring (airshow, firefighting, ag.ops.) |
| Nature: | Agricultural |
| Departure airport: | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
While maneuvering during an aerial application flight at 15 feet above an alfalfa field, the pilot heard a noise emanating from the engine, and it seized. The pilot made a forced landing in the underlying soft field, and the helicopter rolled over after touching down on the uneven terrain. Maintenance records review disclosed that the helicopter's engine had operated about 482 hours since being overhauled. The engine examination revealed that the number two connecting rod was broken at its crankshaft end. Additionally, an inspection of the associated cylinder and piston revealed evidence of detonation. Similar excessive heat exposure signatures were observed with the other five piston heads. A small hole was found chaffed into the fuel primer line. Carbon deposits and burned rotor fingers were found in both magnetos.
Probable Cause: The inadequate nature of the operator's maintenance, which failed to detect the primer and magneto discrepancies. An overly lean fuel mixture and/or magneto cross firing resulted in detonation, an ensuing connecting rod failure, and a total loss of engine power. Contributing factors were the helicopter's low altitude and the uneven, soft nature of the terrain.
Accident investigation:
 |
|
Sources:
NTSB LAX99LA081
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 26-Nov-2017 09:39 | ASN Update Bot | Added |
| 08-Apr-2024 10:29 | ASN Update Bot | Updated [Time, Other fatalities, Phase, 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