# NTSB ANC97LA050: Cessna 170, N4549C, Manley Hot Sprn, AK, March 31, 1997

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 31, 1997, 15:30 local (19:30 UTC)
- Place: Manley Hot Sprn, AK
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 4, 1998
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 2984
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC97LA050
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2984/pdf
- Page: https://openairdocs.org/ntsb/ANC97LA050

## Probable cause

The pilot's selection of an unsuitable landing area.  A factor was the soft snow.

## Sequence of events

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

- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - snow covered (contributing factor)
  - terrain condition - soft (contributing factor)
  - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause)
- Main gear collapsed, landing - roll
  - landing gear,main gear - overload

## Analysis

The pilot reported that he landed his ski equipped airplane on a frozen, snow covered runway.  During the latter portion of the landing roll, the right ski broke through the soft snow, and the right main landing gear collapsed.

## Factual narrative

On March 31, 1997, about 1530 Alaska standard time, a ski equipped Cessna 170B airplane, N4549C, sustained substantial damage while landing on frozen East Twin Lake, located about 33 miles south of Manley Hot Springs, Alaska.  The airline transport certificated pilot and the one passenger aboard were not injured.  The 14 CFR Part 91 pleasure flight departed Fairbanks, Alaska, about 1200.  Visual meteorological conditions prevailed, and a VFR flight plan was in effect.

During a telephone conversation with the NTSB investigator-in-charge on April 8, the pilot related he had just landed the accident airplane on East Twin Lake to go fishing.  During the latter part of the landing roll, the right ski broke through the ice crust, the right main landing gear was pulled from the gear box, and the gear box was pulled away from fuselage.  The right main landing gear collapsed, and the right wing struck the ground.

The NTSB Form 6120.1/2 was not returned by the pilot.

## Aircraft

- Registration: [N4549C](https://openairdocs.org/aircraft/N4549C), registered now, S/N 25493, built 1953 (OpenAirDocs)
- Reported make and model: Cessna 170
- Registry model: [Cessna 170B](https://openairdocs.org/model/cessna-170b) (registry code 2072306) (OpenAirDocs)
- Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 25493
- Engines: Continental C145 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: James W. Watson
- Airworthiness certificate: Standard, Utility; Standard, Normal
- Departed: FAI, FAIRBANKS, AK
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 100 statute miles
- Lowest ceiling: none
- Temperature: 45 °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 19970331006449A](https://openairdocs.org/incident/19970331006449A), Mar 31, 1997: Cessna 170B, Manley Hot Spri, AK, Substantial damage. Landed on frozen lake. Right ski broke thru ice crust. Right gear pulled loose from gear box and folded. Wing hit.

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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