# NTSB LAX93LA076: Curtiss JN-4D, N5001, Livermore, CA, December 26, 1992

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: December 26, 1992, 11:41 local (19:41 UTC)
- Place: Livermore, CA
- Coordinates: 37.679428, -121.749107 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.6794&lon=-121.7491&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report September 28, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27892
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA076
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27892/pdf
- Page: https://openairdocs.org/ntsb/LAX93LA076

## Probable cause

THE SHEARING OF THE NUMBER 8 CYLINDER ROCKER ARM SUPPORT PEDESTAL/COOLANT HOUSING RETAINING BOLTS.  CONTRIBUTING TO THE ACCIDENT WAS A LOSS OF ENGINE COOLANT.

## 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
  - engine assembly,rocker arm/tappet - disengaged (cause)
  - cooling system,fittings - sheared (cause)
  - fluid,coolant - loss,partial (contributing factor)
- Forced landing, descent - emergency
- In flight collision with terrain/water, descent - emergency
  - terrain condition - grass

## Analysis

FOLLOWING TAKE OFF FROM A PRIVATE AIRSTRIP, THE ENGINE BEGAN TO LOOSE POWER AT ABOUT 50 FEET AGL.  THE AIRPLANE BEGAN TO LOOSE ALTITUDE AND AIRSPEED.  THE PILOT BEGAN A LEFT TURN TO AN OPEN FIELD.  THE AIRPLANE CONTINUED IN THE LEFT TURN TOWARD THE PILOTS RESIDENCE.  TO AVOID HITTING THE HOUSE, THE PILOT INTENTIONALLY SKIDDED THE AIRPLANE TO THE LEFT, STRIKING THE GROUND IN FRONT OF THE RESIDENCE.  AN EXAMINATION OF THE ENGINE REVEALED TWO BOLTS THAT RETAIN THE ROCKER ARM SUPPORT PEDESTAL AND ENGINE COOLANT HOUSING HAD SHEARED.  ENGINE COOLANT SPRAYED ONTO THE RIGHT SIDE SPARK PLUG LEADS AND RIGHT SIDE OF THE AIRPLANE.

## Aircraft

- Registration: [N5001](https://openairdocs.org/deregistered/N5001-2017-05-22), registration cancelled 2017-05-22, S/N 5002, built 1918 (OpenAirDocs)
- Reported make and model: Curtiss JN-4D
- Registry model: [Curtiss JENNEY JN-4D](https://openairdocs.org/model/curtiss-jenney-jn-4d) (registry code 0760728) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Airplane
- Serial number: 5002
- Airframe hours: 580
- Engines: Curtis Wright OX5 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: James M. Nissen
- Registered owner: James M. Nissen
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, April 29, 1992, 22 hours before
- Departed: 23Q
- Airport: 23Q, Meadowlark Field

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 77; commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: rear; flight hours: 7,138 total, 500 in this make and model, 6,500 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 5 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 50 °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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