# NTSB LAX84LA476: Cessna 152, N4959H, Rialto, CA, September 8, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 8, 1984, 10:25 local (17:25 UTC)
- Place: Rialto, CA
- Coordinates: 34.100009, -117.379249 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.1000&lon=-117.3792&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24396
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX84LA476
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24396/pdf
- Page: https://openairdocs.org/ntsb/LAX84LA476

## 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, takeoff - initial climb
  - exhaust system - other (cause)
  - engine assembly,push rod - brittle fracture (cause)
  - maintenance,overhaul - improper, other maintenance personnel (cause)
- Abrupt maneuver, descent - emergency
- Hard landing, landing - flare/touchdown
  - aircraft handling - inadequate, pilot in command (cause)
  - flare - misjudged, pilot in command (cause)

## Analysis

THE PLT STATED THAT THIS WAS THE FIRST FLT AFTER THE ENG HAD BEEN OVERHAULED. DURING THE TAKEOFF CLIMB AT AN ALT OF 500 FT THE ENG LOST PWR. THE PLT MADE A HARD LANDING ADJACENT TO THE RWY. EXAM OF THE ENG AFTER THE ACCIDENT REVEALED THE EXHAUST ROCKER ARM ADJUSTING HAD NOT BEEN TORQUED TO THE REQUIRED 450 INCH POUNDS, THUS EXCESSIVE CYLINDER PRESSURE DEVELOPED AND BENT THE INTAKE PUSHROD.

## Aircraft

- Registration: [N4959H](https://openairdocs.org/deregistered/N4959H-2007-02-05), registration cancelled 2007-02-05, S/N 15284046, built 1979 (OpenAirDocs)
- Reported make and model: CESSNA 152
- Registry model: [Cessna 152](https://openairdocs.org/model/cessna-152) (registry code 2071835) (OpenAirDocs)
- Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 15284046
- Airframe hours: 1274
- Engines: LYCOMING O-235-L2C 110 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: R.S. Bumbarner
- Airworthiness certificate: Standard, Utility
- Last inspection: Annual, November 19, 1983, 96 hours before
- Departed: L67, RIALTO, CA
- Destination: L12, REDLANDS, CA
- Airport: L67, Rialto Muni, runway 24, 3,600 × 75 ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 53; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 95 total, 95 in this make and model, 47 as pilot in command, 17 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: 91 °F
- Altimeter: 29.00 inHg

## 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 19840908047629A](https://openairdocs.org/incident/19840908047629A), Sep 8, 1984: Cessna 152, Rialto, CA, Substantial damage. Exhaust rocker arm adjusting screw and lock nut loose on cylinder of topped engine. Bent intake valve pushrod.

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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