# NTSB LAX93LA117: Boeing A75N1, N62733, Hughson, CA, February 12, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 12, 1993, 13:28 local (21:28 UTC)
- Place: Hughson, CA
- Coordinates: 37.4691, -120.850357 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.4691&lon=-120.8504&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report November 15, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27922
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA117
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27922/pdf
- Page: https://openairdocs.org/ntsb/LAX93LA117

## Probable cause

THE FAILURE OF THE INTAKE VALVE.  THE SOFT TERRAIN CONTRIBUTED TO THIS 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, cruise
  - engine assembly,valve,intake - fractured (cause)
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - soft (contributing factor)

## Analysis

SHORTLY AFTER DEPARTING A PRIVATELY OWNED AIRSTRIP THE AIRPLANE EXPERIENCED A ROUGH RUNNING ENGINE FOLLOWED BY A LOSS OF POWER.  THE PILOT EXECUTED A LANDING IN A CULTIVATED OPEN FIELD.  THE AIRPLANE NOSED OVER WHEN THE MAIN WHEELS DUG INTO THE SOFT TERRAIN.  EXAMINATION OF THE ENGINE DISCLOSED THAT AN INTAKE VALVE FRACTURED.

## Aircraft

- Registration: [N62733](https://openairdocs.org/aircraft/N62733), registered now, S/N 75-4700, built 1943 (OpenAirDocs)
- Reported make and model: BOEING A75N1 (A75N-1)
- Registry model: [Boeing A75N1(PT17)](https://openairdocs.org/model/boeing-a75n1-pt17) (registry code 1380134) (OpenAirDocs)
- Registry engine: [Continental W670 series](https://openairdocs.org/engine/continental-w670-series) (registry code 17018, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 75-4700
- Airframe hours: 5345
- Engines: WRIGHT R-975-11 440 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Grauf Flying Service, Inc.
- Registered owner: Grauf Flying Service, Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, January 16, 1993, 4 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 8,535 total, 6,000 in this make and model, 8,124 as pilot in command, 50 in the last 90 days, 20 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 315° at 5 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 55 °F

## 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 19930212002279A](https://openairdocs.org/incident/19930212002279A), Feb 12, 1993: Boeing A75N1, Hughson, CA, Substantial damage. Lost power. Nosed over on forced landing. Intake valve stem had fractured.

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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