# NTSB MIA93LA104: Air Tractor AT-401, N7316L, Fort Pierce, FL, April 17, 1993

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: April 17, 1993, 06:53 local (10:53 UTC)
- Place: Fort Pierce, FL
- Location: 27.4256° N, 80.3404° W: Placed by OpenAirDocs: center of Fort Pierce, FL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=27.4256&lon=-80.3404&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report February 10, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 33256
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA93LA104
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/33256/pdf
- Page: https://openairdocs.org/ntsb/MIA93LA104

## Probable cause

FAILURE OF THE NO. 2 CYLINDER IN FATIGUE FOR UNDETERMINED REASONS, OVER UNSUITABLE TERRAIN.  THE LACK OF SUITALE TERRAIN FOR THE FORCED LANDING WAS A FACTOR.

## 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,cylinder - failure,total (cause)
  - engine assembly,cylinder - fatigue (contributing factor)
- Forced landing, descent - emergency
- In flight collision with object, landing - flare/touchdown
  - terrain condition - none suitable (contributing factor)

## Analysis

THE AGRICULTURAL FLIGHT HAD DEPARTED THE AIRSTRIP AND WAS EN ROUTE TO SPRAY A FIELD WHEN THE ENGINE BEGAN TO RUN ROUGH, SMOKE, AND LOSE POWER. THE PILOT ATTEMPTED TO RETURN TO THE AIRSTRIP BUT THE ENGINE DID NOT PRODUCE ADEQUATE POWER. HE INITIATED A FORCED LANDING TO A DRAINAGE DITCH. DURING THE LANDING THE AIRPLANE HIT A SPRINKLER SYSTEM AND BURST INTO FLAMES. THE NO. 2 CYLINDER WAS FOUND TO BE CRACKED ACROSS THE DOME FROM SPARKPLUG HOLE TO SPARKPLUG HOLE. NO RECORDS WERE FOUND TO DETERMINE THE SERVICE HISTORY OF THE CYLINDER.

## Aircraft

- Registration: [N7316L](https://openairdocs.org/deregistered/N7316L-2013-06-11), registration cancelled 2013-06-11, S/N 401-0675, built 1987 (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 0675
- Airframe hours: 2923
- Engines: P&W 1340-AN1 600 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Aerial application, Part 137
- Operator: Southeastern Aircraft
- Registered owner: Southeastern Aircraft
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 1, 1993, 91 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 61; commercial; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 26,000 total, 143 in the last 90 days, 58 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F
- Altimeter: 29.00 inHg
- Observed at: FPR, 21 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 19930417014409A](https://openairdocs.org/incident/19930417014409A), Apr 17, 1993: Airtrc AT401, Fort Pierce, FL, Destroyed. Lost power en route to spray field. Struck sprinkler system and burned. NR2 cylinder cracked between igniter holes.

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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