LAX87LA275 · Piper PA-28-161
Flying Country Club Piper PA-28-161 · Accident: partial loss of engine power (mechanical failure) en route
From Reid-Hillview Airport of Santa Clara County (RHV) to Buchanan Field (CCR)
Event
- NTSB case
- LAX87LA275
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Piper PA-28-161
- Aircraft type
- Piper PA-28
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N91338
- Operator
- Flying Country Club
- Onboard fatalities
- Unknown
- Route
- From Reid-Hillview Airport of Santa Clara County (RHV), San Jose, CATo Buchanan Field (CCR), Concord, CA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · climb to cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Partial loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Engine assembly, rocker arm/tappet › Fractured
- Manufacturer › Maintenance, service bulletin/letter, inadequate
- Other maintenance personnel › Maintenance, compliance with ad, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
WHILE CLIMBING TO CRUISE PLT HEARD A LOUD KNOCKING NOISE FOLLOWED BY 'VIOLENT VIBRATIONS' & A LOSS OF POWER. PLT MADE A FRCD LNDING IN A NEWLY EXCAVATED CONSTRUCTION SITE & WENT OVER AN EMBANKMENT. INVES REVEALED DEFORMATION OF THE #4 CYLINDER VALVE COVER. #4 EXHAUST VALVE ROCKER ARM WAS FOUND TO BE BROKEN. REVIEW OF ACFT MAINTENANCE RECORDS REVEALED THAT AD 87-10-06 WHICH INCORPORATES LYCOMING SERVICE BULLETIN (SB) 477A WAS ACCOMP 78.7 HRS PRIOR TO THE ACCIDENT. THE SB REQUIRES ROCKER ARMS THAT DO NOT HAVE A WALL THICKNESS OF.075 BE REPLACED. IF THE ROCKER ARM PASSES THE THICKNESS EXAM THE ROCKER ARM OIL DRIP HOLE OUTER EDGE MUST BE 'BURRED' TO THE APPROX .030 RADIUS PRIOR TO REASSEMBLY. THE ROCKER ARM WAS MEASURED USING A ROUND ANVIL MICROMETER. THE MEASUREMENT MET THE MIN DIMENSION OF .075. AFTER THE ACCIDENT, MET LAB EXAM REVEALED FRACTURE FEATURES OF HIGH CYCLE FATIGUE & OVERSTRESS. THE ORIGIN OF THE FATIGUE WAS TRACED TO THE REWORKED OIL DRIP HOLE WHICH DID NOT MEET .030 RADIUS. THE WALL THICKNESS MEASURED .055 USING A MEASURING MICROSCOPE.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record LAX87LA275
- Event ID
- 20001213X31563
- Case number
- LAX87LA275
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: b517f26db361cb8f788527ab7f07213b125fc63baf2a73840cc75073da430013; retrieved 2026-09-22T00:48:02.795Z.