# NTSB DEN84LA206: Grumman G-164A, N4638, Wyndmere, ND, July 1, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 1, 1984, 08:10 local (13:10 UTC)
- Place: Wyndmere, ND
- Coordinates: 46.260341, -97.129035 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.2603&lon=-97.1290&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16421
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN84LA206
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16421/pdf
- Page: https://openairdocs.org/ntsb/DEN84LA206

## Sequence of events

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

- On ground/water encounter with terrain/water, takeoff - roll/run
  - terrain condition - crop (contributing factor)
  - clearance - misjudged, pilot in command (cause)
- Loss of control - on ground/water, takeoff - roll/run
  - directional control - not possible, pilot in command
  - ground loop/swerve - uncontrolled, pilot in command
- Nose over, takeoff
  - terrain condition - wet (contributing factor)
  - terrain condition - soft (contributing factor)

## Analysis

SOD WAS WORN FROM THE MIDDLE OF THE STRIP & THE STRIP WAS WET. THEREFORE, THE PLT ELECTED TO USE THE LEFT SIDE OF THE SOD STRIP FOR TAKEOFF. DURING THE TAKEOFF ROLL, THE LEFT SPRAY BOOM DRAGGED INTO WHEAT THAT WAS GROWING BESIDE THE RWY & THE ACFT VEERED LEFT. STRIPS OF WHEAT ABOUT 30 FT WIDE HAD BEEN PLANTED ON EACH SIDE OF THE RWY. AFTER CROSSING THE WHEAT, THE ACFT WENT INTO A WET BEAN FIELD & NOSED OVER. THE PLT WAS UNAWARE THAT THE BOOM HAD DRAGGED IN THE WHEAT & VEERED THE ACFT UNTIL AFTER THE ACCIDENT.

## Aircraft

- Registration: [N4638](https://openairdocs.org/deregistered/N4638-2015-05-13), registration cancelled 2015-05-13, S/N 1071, built 1973 (OpenAirDocs)
- Reported make and model: GRUMMAN G-164A
- Registry model: [Grumman G-164A](https://openairdocs.org/model/grumman-g-164a) (registry code 3952704) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 1071
- Airframe hours: 4500
- Engines: P&W R-985 reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Thompson Aerial
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 15, 1984
- Airport: NA21, Thompson, runway 36, 2,600 × 60 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 24; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 486 total, 192 in this make and model, 366 as pilot in command, 249 in the last 90 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 75 °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 19840701029009A](https://openairdocs.org/incident/19840701029009A), Jul 1, 1984: Scwzer G164A, Wyndmere, ND, Substantial damage. Spray boom caught in wheat on edge of runway. Pulled aircraft off runway. Aborted and nosed over in a bean field.

## Other investigations on N4638 (2)

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 CEN12LA491](https://openairdocs.org/ntsb/CEN12LA491), Jul 20, 2012: Grumman G-164A (N4638), Fergus Falls, MN, substantial damage. Probable cause: A total loss of engine power due to a cracked No. 2 cylinder head.
- [NTSB FTW77FPG68](https://openairdocs.org/ntsb/FTW77FPG68), Jul 21, 1977: Grumman G-164 (N4638), Keo, AR, substantial damage

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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