# NTSB MKC87DPG03: Air Tractor AT-301, N3159X, Tillar, AR, August 27, 1987

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Final report
- Date: August 27, 1987, 09:07 local (14:07 UTC)
- Place: Tillar, AR
- Coordinates: 33.709899, -91.450515 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.7099&lon=-91.4505&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report February 24, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 34266
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC87DPG03
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34266/pdf
- Page: https://openairdocs.org/ntsb/MKC87DPG03

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, approach
  - propeller system/accessories,dome - disconnected (cause)
  - maintenance,inspection - inadequate (cause)
- Loss of control - in flight, approach
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PILOT STATED THAT THE PROP RPM BECAME ERRATIC. ON APPROACH, THE PROP RAN COMPLETELY OUT OF CONTROL, CAUSING THE AIRCRAFT TO NOSE DOWN INTO A PLOWED FIELD JUST SHORT OF THE LANDING AREA. THE A/C HIT ON THE MAIN LANDING GEAR, BROKE THEM OFF, THEN IT NOSED OVER. INSPECTION OF THE PROPELLER FOUND THAT ALL OF THE DOWEL PINS THAT FIX THE DOME STATIONARY TO THE HUB ASSEMBLY HAD FAILED. THIS FAILURE WAS THE RESULT OF THE BARREL SHIMS BEING PARTIALLY INSTALLED ALONG THE EDGE OF THE DOME INSTEAD OF FLAT AGAINST THE DOME SHELF IN THE HUB. THE RESULT WAS THE BLADES BECOMING DISENGAGED FROM THE GEARING.

## Aircraft

- Registration: [N3159X](https://openairdocs.org/deregistered/N3159X-2018-11-02), registration cancelled 2018-11-02, S/N 301-0475, built 1983 (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: 301-0475
- Airframe hours: 2807
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Robert R. Jacobs., doing business as Jacobs Flying Service
- Registered owner: Delta Sprayers, Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 6, 1987, 607 hours before
- Departed: AR04, TILLAR, AR
- Airport: AR04

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 6,500 total, 2,600 in this make and model, 6,248 as pilot in command, 60 in the last 90 days, 30 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 22° at 5 knots
- Visibility: 7 statute miles
- Lowest ceiling: 10,000 ft broken
- Temperature: 82 °F, dew point 73 °F
- Altimeter: 30.00 inHg
- Observed at: PBF, 40 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 19870827049139A](https://openairdocs.org/incident/19870827049139A), Aug 27, 1987: Airtrc AT301, Tillar, AR, Substantial damage. Propeller went to flat pitch on approach to landing. Nosed over short of runway. Propeller hub dowl pins not secured

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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