# NTSB LAX03LA052: Schweizer 269C, N642KC, Los Banos, CA, December 18, 2002

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 18, 2002, 15:21 local (23:21 UTC)
- Place: Los Banos, CA
- Coordinates: 37.063056, -120.869445
- Nearby events: https://openairdocs.org/map.md?lat=37.0631&lon=-120.8694&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report December 28, 2004
- Report: Approved by Office Director
- Parties: Lycoming, Schweizer, Federal Aviation Administration
- NTSB case key (mKey): 56218
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX03LA052
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/56218/pdf
- Page: https://openairdocs.org/ntsb/LAX03LA052

## Probable cause

The improper engine overhaul by other maintenance personnel, which resulted in an exhaust valve failure and a total loss of engine power while in maneuvering flight.

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, maneuvering
  - engine assembly,valve,exhaust - failure,total (cause)
  - maintenance,rebuild/remanufacture - improper, other maintenance personnel (cause)
- Forced landing, emergency descent/landing
  - autorotation
- In flight collision with terrain/water, emergency descent/landing
  - terrain condition - muddy

## Analysis

The pilot and aircraft maintenance technician were performing a post maintenance test flight when a vibration occurred, followed by a total loss of engine power.  The commercial certificated helicopter pilot made a forced landing in a muddy field, during which the helicopter received structural damage.  Post accident examination revealed a failed exhaust valve in the number 3 cylinder, and that two exhaust spring seats had been installed, one on top of the other, causing excessive spring/valve pressures.  The engine had been overhauled about 1.5 service hours prior to the loss of engine power.

## Factual narrative

On December 18, 2002, at 1521 Pacific standard time, a Schweizer 269C, N642KC, experienced a total loss of engine power and rolled over during a forced landing in a muddy field at Los Banos, California.  The helicopter was operated by the pilot under 14 CFR Part 91.  The commercial pilot and one passenger were not injured.  The helicopter was substantially damaged.  Visual meteorological conditions prevailed, and no flight plan had been filed.  The flight originated at Los Banos about 1500.

The pilot and aircraft maintenance technician were performing a post maintenance test flight when a vibration occurred followed by a total loss of engine power.  Post accident examination revealed a failed exhaust valve in the number 3 cylinder.  Further examination revealed two exhaust spring seats had been installed, one on top of the other, causing excessive spring/valve pressures.  The operator had just overhauled the engine; the failure occurred about 1.5 hours after the overhaul.

## Aircraft

- Registration: [N642KC](https://openairdocs.org/deregistered/N642KC-2008-01-08), registration cancelled 2008-01-08, S/N S1682, built 1994 (OpenAirDocs)
- Reported make and model: Schweizer 269C
- Registry model: [Schweizer 269C](https://openairdocs.org/model/schweizer-269c) (registry code 8059502) (OpenAirDocs)
- Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: S1682
- Airframe hours: 3784.6
- Engines: Avco Lycoming HIO-360-D1A 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: John Raven
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, August 23, 2002, 1.5 hours before
- Departed: LSN, Los Banos, CA
- Airport: LSN, Los Banos

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; injuries: none; private, flight instructor, commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 1,900 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 10° at 3 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 54 °F, dew point 37 °F
- Altimeter: 30.20 inHg
- Observed at: MCE, 22 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 20021218034469A](https://openairdocs.org/incident/20021218034469A), Dec 18, 2002: Hughes 269C, Losbanos, CA, Substantial damage. (-23) Aircraft was on initial maintenance check flight after the installation of an overhauled engine. As the aircraft was returning to the airport, (lsn) the…

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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