# NTSB LAX90LA259: Cessna 421C, N6089X, Lancaster, CA, July 18, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 18, 1990, 09:33 local (16:33 UTC)
- Place: Lancaster, CA
- Coordinates: 34.719875, -118.47908 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.7199&lon=-118.4791&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 5 uninjured
- Status: Completed, report November 23, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26870
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90LA259
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26870/pdf
- Page: https://openairdocs.org/ntsb/LAX90LA259

## Probable cause

THE ACCIDENT WAS ERODED IGNITION SPARK PLUG ELECTRODES AND MAINTENANCE PERSONNEL NEGLECTING TO ADJUST SPARK PLUG ELECTRODES AND MAINTENANCE PERSONNEL NEGLECTING TO ADJUST SPARK PLUG GAP. THE ROUGH TERRAIN IN WHICH THE AIRCRAFT LANDED WAS A FACTOR IN THE ACCIDENT.

## 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
  - ignition system,spark plug - eroded (cause)
  - maintenance,adjustment - not performed, other maintenance personnel (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - rough/uneven (contributing factor)

## Analysis

ERODED IGNITION SPARK PLUG ELECTRODES AND MAINTENANCE PERSONNEL NEGLECTING TO ADJUST SPARK PLUG ELECTRODES AND MAINTENANCE PERSONNEL NEGLECTING TO ADJUST SPARK PLUG GAP. THE ROUGH TERRAIN IN WHICH THE AIRCRAFT LANDED WAS A FACTOR IN THE ACCIDENT.

## Aircraft

- Registration: [N6089X](https://openairdocs.org/deregistered/N6089X-1993-07-13), registration cancelled 1993-07-13, S/N 421C0887 (OpenAirDocs)
- Reported make and model: CESSNA 421C
- Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (registry code 2076016) (OpenAirDocs)
- Category: Airplane
- Serial number: 421C0887
- Engines: CONTINENTAL GTSI-O-520-L 375 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Pacifica Corporation
- Registered owner: Unknown
- Departed: WJF
- Destination: APV, APPLE VALLEY, CA
- Airport: WJF, Gen. William J Fox, runway 24, 5,001 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; flight hours: 59,000 total, 402 in this make and model, 42,000 as pilot in command, 270 in the last 90 days, 90 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 5 knots
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F
- Observed at: WJF, 1 nm away

## 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 19900718030589A](https://openairdocs.org/incident/19900718030589A), Jul 18, 1990: Cessna 421C, Lancaster, CA, Substantial damage. Lost power on climbout. Landed gear up to avoid wires. Igniters worn and sooted. Had recent annual inspection.

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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