# NTSB SEA89LA071: Air Tractor AT-301, N4340S, Grangeville, ID, April 17, 1989

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: April 17, 1989, 09:15 local (16:15 UTC)
- Place: Grangeville, ID
- Coordinates: 45.900787, -116.130218 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.9008&lon=-116.1302&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report January 22, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 40998
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA89LA071
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40998/pdf
- Page: https://openairdocs.org/ntsb/SEA89LA071

## Probable cause

A PARTIAL POWER LOSS DUE TO A BLOWER FAILURE. A FACTOR RELATED TO THE ACCIDENT WAS THE SOFT FIELD CONDITION.

## 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
  - eng assembly,blower/impeller/integral supercharger - failure,total (cause)
- Forced landing, descent - emergency
  - load jettison - performed
- Nose over, landing - roll
  - terrain condition - soft (contributing factor)

## Analysis

A PARTIAL POWER LOSS OCCURRED DRG INITIAL CLIMB. THE PLT JETTISONED HIS LOAD & LANDED IN A SOFT FIELD ABOUT 3/4 MI FROM THE RWY, WHERE THE ACFT NOSED OVER. A FIRE ERUPTED, WHICH SELF-EXTINGUISHED MINUTES LATER. THE OPERATOR RPRTD THAT A 10 INCH DROP IN MANIFOLD PRESSURE HAD OCCURRED & THAT A SUSPECTED BLOWER FAILURE WAS THE REASON FOR THE POWER LOSS.

## Aircraft

- Registration: [N4340S](https://openairdocs.org/deregistered/N4340S-2018-03-22), registration cancelled 2018-03-22, S/N 301-0020, built 1975 (OpenAirDocs)
- Reported make and model: AIR TRACTOR AT-301
- Registry model: [Air Tractor AT-301](https://openairdocs.org/model/air-tractor-at-301) (registry code 0390103) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 301-0020
- Airframe hours: 5745
- Engines: P&W R-1340-AN-1 600 horsepower reciprocating
- Damage: Substantial damage
- Fire: On-Ground
- Flight: Aerial application, Part 137
- Operator: Thomas Hill, doing business as Grangeville Air Service, Inc.
- Registered owner: Grangeville Air Service Inc
- Airworthiness certificate: Special, Limited (Special)
- Last inspection: Annual, November 28, 1988, 72 hours before
- Airport: Idaho County, runway 7, 4,800 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 2,052 total, 38 in this make and model, 1,952 as pilot in command, 75 in the last 90 days, 42 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 45° at 2 knots
- Visibility: 15 statute miles
- Lowest ceiling: 2,500 ft broken
- Temperature: 45 °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 19890417008239A](https://openairdocs.org/incident/19890417008239A), Apr 17, 1989: Airtrc AT301, Grangeville, ID, Substantial damage. Engine super charger failed on climbout for ag flight. Dumped load. Landed in soft field and nosed over.

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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