ASN Wikibase Occurrence # 131829
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 17 August 1999 |
| Time: | 11:31 LT |
| Type: |  Beechcraft J35 Bonanza |
| Owner/operator: | Kleco Inc |
| Registration: | N4932B |
| MSN: | D-5541 |
| Total airframe hrs: | 5202 hours |
| Engine model: | Continental IO-470-C |
| Fatalities: | Fatalities: 0 / Occupants: 2 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | Marysville, CA -
 United States of America
|
| Phase: | En route |
| Nature: | Private |
| Departure airport: | San Rafael, CA |
| Caldwell, ID (U35) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The pilot radioed that the aircraft's engine was failing and he was altering his course to land at the nearest airport. While on left base leg for landing, the cowling flew open, oil filled the windshield, and the engine ceased delivering power. The aircraft impacted a tree and came to rest in a city park. At the scene, the No. 6 engine cylinder was separated from the crankcase and engine components associated with that cylinder were found over a 40-foot radius around the aircraft. The engine crankcase where the No. 6 cylinder attached was broken away at the 12 o'clock position; the upper forward, upper rear, and lower rear mounting studs were broken; and the lower forward stud and the two lower center studs were present. The skirt of the No. 6 cylinder exhibited a pattern of longitudinal striations where it mated into the crankcase opening. At the lower left of the cylinder mount location was a small ledge of material, which approximated the shape of the circumference of the cylinder base flange. Opposite this location, on the upper right of the cylinder mounting location, was a brightly polished wear area. The engine received a top overhaul 7 months, 41.8 hours prior to the accident. Breakaway torque was measured on the remaining cylinder base nuts and found to range between 25 and 40 foot-pounds; the specification torque values are between 40.8 and 42.5.
Probable Cause: A loss of engine power due to improperly torque cylinder base nuts by maintenance personnel during a top overhaul.
Accident investigation:
 |
|
Sources:
NTSB LAX99FA270
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 21-Dec-2016 19:25 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 14-Dec-2017 08:46 | ASN Update Bot | Updated [Departure airport, Destination airport, Source, Narrative] |
| 07-Apr-2024 18:38 | ASN Update Bot | Updated [Time, Other fatalities, 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