# NTSB LAX91LA347: Experimental RV4, N835B, Napa, CA, August 5, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 4, 1991, 19:20 local (Aug 5, 1991, 03:20 UTC)
- Place: Napa, CA
- Coordinates: 38.549114, -122.149208 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.5491&lon=-122.1492&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 27, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27318
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91LA347
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27318/pdf
- Page: https://openairdocs.org/ntsb/LAX91LA347

## Probable cause

THE INSTALLATION OF A NON COMPATIABLE OIL FILTER AND SYSTEM PLUMBING CHANGES WHICH INDUCED THE OIL EXHAUSTION EVENT RESULTING IN A FORCED LANDING AND IN FLIGHT COLLISION WITH TERRAIN.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - mech failure/malf, cruise - normal
  - lubricating system,oil filter/screen - incorrect (cause)
  - lubricating system,oil line - improper (cause)
  - lubricating system,oil filter/screen - burst (cause)
  - maintenance,installation - improper, pilot in command (cause)
  - fluid,oil - exhaustion (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - high vegetation

## Analysis

THE PILOT SAID THE AIRCRAFT WAS IN CRUISE FLIGHT WHEN THE OIL PRESSURE SUDDENLY DROPPED. THE ENGINE BEGAN TO RUN ROUGH, THEN SEIZED ALTOGETHER. THE AIRCRAFT WAS CLOSE TO A PRIVATE AIRSTRIP AND THE PILOT WAS ATTEMPTING A FORCED LANDING ON THE AIRSTRIP. THE AIRCRAFT LANDED SHORT OF THE RUNWAY IN A GRAPE VINEYARD. RESPONDING SHERIFF'S DEPUTIES REPORTED THAT THE ENTIRE BELLY OF THE AIRCRAFT WAS HEAVILY COATED WITH OIL. FAA AIRWORTHINESS INSPECTORS EXAMINED THE AIRCRAFT AND FOUND THAT AN AUTOMOTIVE FRAM OIL FILTER WAS INSTALLED ON THE ENGINE, WITH SOME PLUMBING CHANGES. THE INSPECTOR STATED THAT THE OIL FILTER FAILED TO BYPASS OIL. THE OUTSIDE CASE OF THE FILTER WAS FOUND TO HAVE EXPANDED TO ABOUT 125 PERCENT OF NORMAL SIZE AND WAS LEAKING OIL.

## Aircraft

- Registration: N835B (not matched to a registry record)
- Reported make and model: EXPERIMENTAL RV4
- Category: Airplane, amateur-built
- Serial number: 1171
- Engines: LYCOMING O-320-B3B 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Stephan D. Barnes

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; flight hours: 1,541 total, 100 in this make and model, 1,400 as pilot in command, 40 in the last 90 days, 21 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: calm
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point -0 °F

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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