# NTSB LAX87DUG06: Curtiss JN-4, N3712, Riverside, CA, August 5, 1987

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: August 5, 1987, 07:20 local (14:20 UTC)
- Place: Riverside, CA
- Coordinates: 33.899608, -117.399627 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.8996&lon=-117.3996&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report February 24, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 25301
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX87DUG06
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25301/pdf
- Page: https://openairdocs.org/ntsb/LAX87DUG06

## Sequence of events

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

- Loss of engine power, cruise - normal
  - cooling system,pump - leak (cause)
  - fuel system,carburetor - contamination (cause)
- Forced landing, descent - emergency
- Hard landing, landing - flare/touchdown
  - flare - premature, pilot in command (cause)
  - altitude - misjudged, pilot in command (contributing factor)

## Analysis

DURING A BUSINESS FLIGHT, THE ENGINE EXPERIENCED A LOSS OF ENGINE POWER. THE PILOT MADE A FORCED LANDING IN AN OPEN AREA WHERE DURING THE TOUCHDOWN, THE AIRCRAFT WAS SUBSTANTIALLY DAMAGED. THE PLT STALLED THE ACFT WHILE STILL SEVERAL FT OFF THE GROUND. THE ACFT RT WING DROPPED AND THE ACFT TURNED RT BEFORE CRASHING IN A CONSTRUCTION SITE PARKING LOT. ACCORDING TO AN ENGINE OVERHAUL FACILITY, THIS ENGINE HAD A COOLANT PUMP LOCATED DIRECTLY ABOVE THE CARBURETOR. THIS PUMP HAD A HISTORY OF LEAKING, AND WOULD CAUSE A SUBSTANTIAL POWER LOSS WHEN NOT MAINTAINED CORRECTLY. THE LEAKING COOLANT PUMP WOULD INTRODUCE CONTAMINATES THROUGH SEVERAL PORTS IN THE CARBURETOR.

## Aircraft

- Registration: [N3712](https://openairdocs.org/aircraft/N3712), registered now, S/N 3712, built 1918 (OpenAirDocs)
- Reported make and model: CURTISS JN-4
- Registry model: [Curtiss JN4D](https://openairdocs.org/model/curtiss-jn4d) (registry code 0760739) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Airplane
- Serial number: 3712
- Engines: Curtis Wright OX-X6 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Wentworth, Charles G.
- Registered owner: Ramon E Folsom
- Airworthiness certificate: Special, Experimental (Special)
- Departed: L67, RUBIDOUX, CA
- Destination: L66, CORONA, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; commercial; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: rear; flight hours: 6,500 total, 30 in this make and model, 6,370 as pilot in command, 65 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 72 °F
- Altimeter: 29.00 inHg
- Observed at: RAL

## 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 19870805047369A](https://openairdocs.org/incident/19870805047369A), Aug 5, 1987: Curtis JN4DJENNY, Riverside, CA, Substantial damage. The engine lost power and the aircraft stalled short of the runway. Leaking water pump seal affected carburetor.

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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