# NTSB FTW92LA134: Air Tractor AT-501, N1006T, Mooreland, OK, May 14, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 14, 1992, 14:00 local (19:00 UTC)
- Place: Mooreland, OK
- Coordinates: 36.430469, -99.199371 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.4305&lon=-99.1994&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report July 26, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18496
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW92LA134
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18496/pdf
- Page: https://openairdocs.org/ntsb/FTW92LA134

## Probable cause

THE FAILURE OF THE NUMBER 3 CYLINDER FOR UNDETERMINED REASONS.  A FACTOR WAS THE LACK OF SUITABLE TERRAIN FOR THE ENSUING FORCED LANDING.

## 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, maneuvering - aerial application
  - engine assembly,cylinder - failure,total (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - object - tree(s)
  - terrain condition - none suitable (contributing factor)
- Nose down, landing - roll
  - terrain condition - rough/uneven

## Analysis

THE PILOT STATED THAT THE ENGINE BACKFIRED SEVERAL TIMES AND LOST POWER AS HE WAS COMPLETING A TURN TO REVERSE DIRECTION AND LINING UP FOR A SWATH RUN.  HE DUMPED THE CHEMICAL LOAD AND APPLIED FULL THROTTLE, MIXTURE, AND PROPELLER, BUT THE ACTIONS DID NOT ALLEVIATE THE POWER LOSS.  HE ELECTED TO LAND ON A NEARBY RIDGE LINE.  DURING THE LANDING ROLL, THE AIRPLANE COLLIDED WITH SEVERAL TREES AND ROUGH TERRAIN AND NOSED DOWN.  EXAMINATION OF THE ENGINE REVEALED THAT THE NUMBER 2 CYLINDER HAD FAILED FOR UNDETERMINED REASONS.  THE OPERATOR REPORTED THIS WAS THE FOURTH CYLINDER FAILURE THAT HE HAD EXPERIENCED ON THIS ENGINE SINCE A MAJOR OVERHAUL 710 HOURS PRIOR TO THE ACCIDENT.

## Aircraft

- Registration: [N1006T](https://openairdocs.org/deregistered/N1006T-2002-07-25), registration cancelled 2002-07-25, S/N 501-0030, built 1988 (OpenAirDocs)
- Reported make and model: AIR TRACTOR AT-501
- Registry model: [Air Tractor AT-501](https://openairdocs.org/model/air-tractor-at-501) (registry code 0390302) (OpenAirDocs)
- Registry engine: [Walter NZ](https://openairdocs.org/engine/walter-nz) (registry code 64001, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 501-0030
- Engines: P&W R-1340-S3 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Eubank, Terry W., doing business as Western Aero Ag
- Registered owner: Eubank, Terry W.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, February 1, 1992, 60 hours before
- Departed: WWR, WOODWARD, OK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 7,935 total, 58 in this make and model, 7,935 as pilot in command, 46 in the last 90 days, 15 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 3 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 84 °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 19920514014939A](https://openairdocs.org/incident/19920514014939A), May 14, 1992: Airtrc AT502, Mooreland, OK, Substantial damage. Cylinder failed. Engine backfired,lost power. Elected to land on a ridge. Struck trees and nosed down.

## Other investigations on N1006T (1)

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.

- [NTSB IAD98WA029](https://openairdocs.org/ntsb/IAD98WA029), Jan 24, 1998: Air Tractor AT-501W (N1006T), Santa Maria, Portugal, destroyed, 1 fatal

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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