# NTSB MKC89LA105: Weatherly 620TP, N4607C, Montrose, AR, May 8, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 8, 1989, 09:00 local (14:00 UTC)
- Place: Montrose, AR
- Coordinates: 33.320903, -91.559783 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.3209&lon=-91.5598&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 29, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 34787
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC89LA105
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34787/pdf
- Page: https://openairdocs.org/ntsb/MKC89LA105

## Probable cause

FAILURE OF THE PILOT IN COMMAND TO MAINTAIN CONTROL OF THE AIRCRAFT DURING LANDING ADVERSELY AFFECTED BY THE EXISTANCE OF A TAILWIND OF AVERAGE PROPORTIONS.

## Sequence of events

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

- Loss of control - on ground/water, landing - roll
  - weather condition - tailwind (contributing factor)
  - proper touchdown point - not attained, pilot in command (contributing factor)
  - wrong runway - selected, pilot in command (cause)
  - aircraft control - not maintained, pilot in command (cause)
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - ditch (contributing factor)

## Analysis

THE PILOT SAID THAT WHILE ATTEMPTING TO LAND DOWN WIND, DURING AN AERIAL APPLICATION OPERATION, HE LOST DIRECTIONAL CONTROL. HE OVERRAN THE AIRSTRIP AND COLLIDED WITH A DITCH CAUSING SUBSTANTIAL DAMAGE TO THE ACFT. POST ACCIDENT INVESTIGATION FAILED TO REVEAL ANY MALFUNCTION OR BRAKE FAILURE THAT MIGHT HAVE CONTRIBUTED TO THE ACCIDENT. THE PLT DID NOT FILE AN ACC REPORT.

## Aircraft

- Registration: [N4607C](https://openairdocs.org/deregistered/N4607C-1996-02-22), registration cancelled 1996-02-22, S/N 1508TP (OpenAirDocs)
- Reported make and model: WEATHERLY 620TP
- Registry model: [Weatherly 620TP](https://openairdocs.org/model/weatherly-620tp) (registry code 9630604) (OpenAirDocs)
- Category: Airplane
- Serial number: 1508TP
- Engines: P&W PT6A-11AG 500 horsepower turbo prop
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Montrose Air Service, Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Departed: MONTROSE, AR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; commercial; airplane ratings: single-engine land, multi-engine land; medical: class 2, valid medical--w/ waivers/lim; flight hours: 9,800 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 130° at 9 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point -0 °F
- Altimeter: 30.00 inHg
- Observed at: GLH, 25 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 19890508011609A](https://openairdocs.org/incident/19890508011609A), May 8, 1989: Wthrly 620TP, Montrose, AR, Substantial damage. Overran the runway into a ditch on landing. Was landing downwind.

## Other investigations on N4607C (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 FTW94LA297](https://openairdocs.org/ntsb/FTW94LA297), Sep 13, 1994: Weatherly 620TP (N4607C), Montrose, AR, substantial damage. Probable cause: THE PILOT'S FAILURE TO MAINTAIN AIRSPEED AND THE RESULTANT AERODYNAMIC STALL.

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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