# NTSB DEN86LA247: Grumman AA-1A, N6401L, Chinook, MT, September 4, 1986

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: September 4, 1986, 15:30 local (21:30 UTC)
- Place: Chinook, MT
- Coordinates: 48.46912, -109.209091 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.4691&lon=-109.2091&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 17046
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN86LA247
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17046/pdf
- Page: https://openairdocs.org/ntsb/DEN86LA247

## Sequence of events

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

- Loss of control - in flight, takeoff - initial climb
  - lift-off - premature, pilot in command
  - total, pilot in command (contributing factor)
  - stall/mush - inadvertent, pilot in command (cause)
- In flight collision with object, takeoff - initial climb
  - object - fence
  - proper climb rate - not attained, pilot in command (contributing factor)

## Analysis

THE ACFT TOOK OFF ON A 3900-FOOT DRY ASPHALT RWY. AN UNCOMMANDED LEFT YAW DEVELOPED WHICH THE PLT WAS UNABLE TO COUNTER. THE ACFT STRUCK A FENCE OFF THE LEFT SIDE OF THE RWY AND NOSED OVER.

## Aircraft

- Registration: [N6401L](https://openairdocs.org/deregistered/N6401L-2013-04-29), registration cancelled 2013-04-29, S/N AA1A-0401, built 1972 (OpenAirDocs)
- Reported make and model: GRUMMAN AA-1A
- Registry model: [American AA-1A](https://openairdocs.org/model/american-aa-1a) (registry code 0630710) (OpenAirDocs)
- Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: AA1A-0401
- Airframe hours: 1054
- Engines: LYCOMING O-235-C2C 108 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Alan D. Hamilton
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, January 9, 1986
- Departed: S71, CHINOOK, MT
- Destination: HVR, HAVRE, MT
- Airport: S71, Chinook Muni, runway 26, 3,900 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 70 total, 7 in this make and model, 48 as pilot in command, 7 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 9 knots, gusting 12
- Visibility: 65 statute miles
- Lowest ceiling: 200 ft broken
- Temperature: 72 °F, dew point 37 °F
- Altimeter: 30.00 inHg
- Observed at: HVR, 24 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 19860904046069A](https://openairdocs.org/incident/19860904046069A), Sep 4, 1986: Gulstm AA1A, Chinook, MT, Substantial damage. The aircraft drifted into a fence after takeoff. Suspect passenger inadvertantly restricted control movements.

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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