# NTSB ANC94LA137: Piper PA-18-150, N3930Z, Port Alsworth, AK, September 15, 1994

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 14, 1994, 20:15 local (Sep 15, 1994, 04:15 UTC)
- Place: Port Alsworth, AK
- Coordinates: 60.199131, -154.27919 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=60.1991&lon=-154.2792&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 10, 1995
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 2568
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC94LA137
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2568/pdf
- Page: https://openairdocs.org/ntsb/ANC94LA137

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN A POSITIVE RATE OF CLIMB.

## Sequence of events

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

- In flight collision with object, takeoff - initial climb
  - proper climb rate - not obtained/maintained, pilot in command (cause)
  - object - tree(s)

## Analysis

THE PILOT REPORTED THAT AFTER LIFTOFF FROM THE REMOTE LAKE, THE AIRPLANE WAS CLIMBING AT THE BEST ANGLE OF CLIMB AIRSPEED WHEN IT ENCOUNTERED 'DEAD AIR'. THE AIRSPEED BEGAN TO DECREASE, AND THE AIRPLANE BEGAN TO LOSE ALTITUDE. IT THEN COLLIDED WITH SEVERAL TREES ABOUT 1/2 MI FROM THE POINT OF DEPARTURE. THE PILOT DESCRIBED THE WIND CONDITIONS AS LIGHT AND VARIABLE.

## Factual narrative

On September 14, 1994, at 2015 Alaska daylight time, a float equipped Piper PA-18 airplane, N3930Z, owned and operated by 4W Air of Soldotna, Alaska, a 14 CFR Part 135 on-demand commercial operator, collided with a tree during the takeoff climb from Nikabuna Lakes, approximately 35 miles southwest of Port Alsworth, Alaska.  The commercial certificated pilot-in-command and his one passenger, the sole occupants, were not injured and the airplane sustained substantial damage.  The 14 CFR Part 135 flight was conducted for the purpose of hunting for moose.  A company VFR flight plan was in effect and visual meteorological conditions with calm winds prevailed at the time of the accident.

The pilot reported that after becoming airborne, the airplane was climbing at the best angle of climb airspeed.  The airplane then encountered what the pilot described as "dead air". The airspeed began to decrease and the airplane lost altitude.  While in a shallow left bank turn, the right wing of the plane collided with a tree about 1/2 mile from the departure point.  The airplane then struck additional trees and descended to the ground.

## Aircraft

- Registration: [N3930Z](https://openairdocs.org/aircraft/N3930Z), registered now, S/N 18-7777 (OpenAirDocs)
- Reported make and model: PIPER PA-18-150
- Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 18-7777
- Airframe hours: 2284
- Engines: LYCOMING O-320-A2B 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Operator: 4w Air
- Registered owner: Woodin, Bill
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, September 9, 1993, 52 hours before
- Destination: AK
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 1,248 total, 39 in this make and model, 1,155 as pilot in command, 230 in the last 90 days, 92 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 20 statute miles
- Lowest ceiling: 3,000 ft overcast
- Temperature: 50 °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 19940914027949A](https://openairdocs.org/incident/19940914027949A), Sep 14, 1994: Piper PA18150, Port Alsworth, AK, Substantial damage. Float equipped PA18 struck trees on climbout from a lake. Reported dead air on climbing turnout. Moose hunting trip

## Other investigations on N3930Z (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 ANC68D0037](https://openairdocs.org/ntsb/ANC68D0037), May 12, 1967: Piper PA-18 (N3930Z), Paxson, 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.

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