# NTSB LAX90LA241: Cessna 152, N48418, Fullerton, CA, July 2, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 2, 1990, 16:11 local (23:11 UTC)
- Place: Fullerton, CA
- Location: 33.8857° N, 117.9280° W: Placed by OpenAirDocs: center of Fullerton, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=33.8857&lon=-117.9280&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report November 23, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26856
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90LA241
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26856/pdf
- Page: https://openairdocs.org/ntsb/LAX90LA241

## Probable cause

THE WARPED CONDITION OF THE ENGINE VALVES AND VALVE SEATS DUE TO EXCESSIVE AND REPEATED THERMAL SHOCK CYCLES.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, cruise
  - engine assembly,valve,exhaust - warped (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - object - undetermined

## Analysis

THE STUDENT SAID THAT WHILE FLYING TOWARD THE AIRPORT, THE ENGINE POWER OUTPUT SUDDENLY DROPPED AND VARIED BETWEEN 900 AND 1,400 RPM. THE POWER WAS INSUFFICIENT TO MAINTAIN FLIGHT AND THE STUDENT SAID HE REALIZED HE COULD NOT MAKE THE AIRPORT. HE SAW A LEVEL DIRT ROAD AT A CONSTRUCTION SITE AND MADE A FORCED LANDING. THE AIRCRAFT CONTACTED GROUND OBSTACLES DURING THE LANDING ROLL AND NOSED OVER. TEARDOWN OF THE ENGINE REVEALED THAT ALL VALVES AND VALVE SEATS WERE WARPED, WITH EVIDENCE OF EXHAUST GASSES ENTERING THE INTAKE PORTS. THE ENGINE WAS REPORTEDLY AT TBO.

## Aircraft

- Registration: [N48418](https://openairdocs.org/deregistered/N48418-1991-02-08), registration cancelled 1991-02-08, S/N 15283337 (OpenAirDocs)
- Reported make and model: CESSNA 152
- Registry model: [Cessna 152](https://openairdocs.org/model/cessna-152) (registry code 2071835) (OpenAirDocs)
- Category: Airplane
- Serial number: 15283337
- Engines: LYCOMING O-235-L2C 110 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Aviation Facilities, Inc.
- Registered owner: Unknown
- Departed: FUL
- Destination: FUL

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 21; student; medical: class 3, valid medical--no waivers/lim.; flight hours: 58 total, 58 in this make and model, 21 as pilot in command, 37 in the last 90 days, 6 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 200° at 9 knots
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19900702023449A](https://openairdocs.org/incident/19900702023449A), Jul 2, 1990: Cessna 152, Fullerton, CA, Substantial damage. Engine lost power. Nosed over on forced landing. All valves and seats warped from excessive thermal shock cycles.

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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