# NTSB ANC86LA093: Piper PA-20, N6910K, Tolsona Lake, AK, June 28, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 28, 1986, 15:05 local (23:05 UTC)
- Place: Tolsona Lake, AK
- Coordinates: 62.100223, -145.529617 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=62.1002&lon=-145.5296&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4688
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC86LA093
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4688/pdf
- Page: https://openairdocs.org/ntsb/ANC86LA093

## 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
  - in-flight planning/decision - inaccurate, pilot in command (cause)
  - wind information - not understood, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - airspeed - not maintained, pilot in command (contributing factor)
  - stall - inadvertent, pilot in command (cause)

## Analysis

THE PRIVATE PILOT ATTEMPTED TO TURN DOWNWIND WHEN HE ENCOUNTERED DOWNDRAFT CONDITIONS DURING A FLOATPLANE TAKEOFF. THE AIRPLANE STALLED AND CRASHED INTO THE LAKE HE DEPARTED FROM.

## Aircraft

- Registration: [N6910K](https://openairdocs.org/deregistered/N6910K-2019-02-12), registration cancelled 2019-02-12, S/N 20-5 (OpenAirDocs)
- Reported make and model: PIPER PA-20
- Registry model: [Piper PA-20](https://openairdocs.org/model/piper-pa-20) (registry code 7102002) (OpenAirDocs)
- Category: Airplane
- Serial number: 20-5
- Airframe hours: 2270
- Engines: LYCOMING O-320-AB 150 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Gary Kent Watson
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 27, 1986, 3 hours before
- Departed: AK58, TOLSONA LAKE, AK
- Destination: LONG LAKE, AK
- Airport: AK58, Tolsona Lake

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; private; airplane ratings: single-engine land, single-engine sea; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 167 total, 167 in this make and model, 123 as pilot in command, 45 in the last 90 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 150° at 10 knots, gusting 15
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 70 °F, dew point -0 °F
- Altimeter: 29.00 inHg

## 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 19860628028339A](https://openairdocs.org/incident/19860628028339A), Jun 28, 1986: Piper STCPA20, Tolsona Lake, AK, Destroyed. The aircraft stalled during a low altitude turn in downdraft conditions. The floatplane struck the lake and flipped

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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