# NTSB MKC90LA081: Air Tractor AT-401, N1015A, Hornersville, MO, April 5, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 5, 1990, 13:00 local (18:00 UTC)
- Place: Hornersville, MO
- Coordinates: 36.039653, -90.110786 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.0397&lon=-90.1108&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 5, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 34957
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC90LA081
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34957/pdf
- Page: https://openairdocs.org/ntsb/MKC90LA081

## Probable cause

FAILURE OF AN ENGINE CYLINDER.

## 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, takeoff - initial climb
  - engine assembly,cylinder - failure,total (cause)
- Forced landing, descent - emergency
- Nose over, landing
  - terrain condition - none suitable (contributing factor)
  - terrain condition - soft (contributing factor)
  - terrain condition - wet (contributing factor)

## Analysis

THE PILOT SAID THAT SHORTLY AFTER TAKEOFF, DURING AN AERIAL APPLICATION OPERATION, THE ENGINE FAILED. AN EMERGENCY LANDING WAS MADE IN A SOFT, MUDDY FARM FIELD, RESULTING IN A NOSE OVER AND SUBSTANTIAL DAMAGE TO THE ACFT. A POST-ACCIDENT INVESTIGATION REVEALED THE #9 CYLINDER ON THE POWERPLANT HAD FAILED.

## Aircraft

- Registration: [N1015A](https://openairdocs.org/aircraft/N1015A), registered now, S/N 401-0735 (OpenAirDocs)
- Reported make and model: AIR TRACTOR AT-401
- Registry model: [Air Tractor AT-401](https://openairdocs.org/model/air-tractor-at-401) (registry code 0390204) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 401-0735
- Airframe hours: 57
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Simonton & Winborn
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, September 27, 1989, 57 hours before
- Departed: 37M, HORNERSVILLE, MO
- Airport: 37M, Hornersville, runway 18, 2,640 × 50 ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 3,750 total, 150 in this make and model, 3,650 as pilot in command, 130 in the last 90 days, 110 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 5 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point -0 °F
- Altimeter: 29.00 inHg

## 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 19900405007739A](https://openairdocs.org/incident/19900405007739A), Apr 5, 1990: Airtrc AT401, Hornersville, MO, Substantial damage. Engine quit on gross weight takeoff. Landed in muddy field and nosed over. NR9 cylinder had failed.

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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