# NTSB ANC86LA012: Piper PA-20, N97MM, Shageluk, AK, December 6, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 6, 1985, 16:15 local (20:15 UTC)
- Place: Shageluk, AK
- Coordinates: 62.640068, -159.530548 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=62.6401&lon=-159.5305&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4625
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC86LA012
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4625/pdf
- Page: https://openairdocs.org/ntsb/ANC86LA012

## Sequence of events

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

- In flight collision with object, landing
  - window,flight compartment window/windshield - dirty(foggy) (contributing factor)
  - visual lookout - poor, pilot in command (cause)
  - operation with known deficiencies in equipment - intentional, pilot in command (cause)
  - light condition - dusk (contributing factor)
  - judgment - poor, pilot in command (contributing factor)
  - object - tree(s) (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE ACFT CONTACTED TREES AND DESCENDED TO THE TERRAIN WHILE ON AN APCH TO A LAKE. THE PLT REPORTED THE ACFT WINDSCREEN KEPT FROSTING UP AND HE HAD TO REPEATEDLY WIPE IT CLEAN. IN THE PROCESS OF WIPING THE WINDSCREEN HE APPROACHED THE LAKE AT A LOWER THAN INTENDED ALT AND THE ACFT CONTACTED THE 60 FT TALL TREES. THE PLT STATED HE HAD PURCHASED A WINDSCREEN HEATER BUT HAD NOT YET INSTALLED IT.

## Aircraft

- Registration: [N97MM](https://openairdocs.org/deregistered/N97MM-2005-11-14), registration cancelled 2005-11-14, S/N 20-41 (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: 20-41
- Engines: LYCOMING O-320 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Kenneth W. Chase
- Airworthiness certificate: Standard, Normal
- Departed: SHX, SHAGELUK, AK
- Destination: ANV, ANVIK, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; private; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 1,500 total, 1,000 in this make and model

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: 270° at 5 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 30 °F, dew point -0 °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 19851206061179A](https://openairdocs.org/incident/19851206061179A), Dec 6, 1985: Piper STCPA20, Shageluk, AK, Substantial damage. Struck a tree during approach to frozen lake. Windshield was frosted and pilot had sun in his eyes.

## Other investigations on N97MM (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 ANC84LA010](https://openairdocs.org/ntsb/ANC84LA010), Oct 24, 1983: Piper PA-20 (N97MM), Anchorage, AK, 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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.