# NTSB WPR09CA041: WSK PZL Mielec M-18A, N81705, Mountain Home, ID, November 8, 2008

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: November 8, 2008, 12:00 local (19:00 UTC)
- Place: Mountain Home, ID
- Coordinates: 43.131389, -115.730552 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.1314&lon=-115.7306&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Defining event: [Standing-engine(s) operating: Ground handling event](https://openairdocs.org/ntsb-events/080)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report December 24, 2008
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 69475
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09CA041
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/69475/pdf
- Page: https://openairdocs.org/ntsb/WPR09CA041

## Probable cause

The pilot's inadequate preflight inspection, and, his failure to properly secure the aircraft as he left the cockpit with the engine operating, which resulted in the unoccupied airplane inadvertently becoming airborne and colliding with a fence and terrain.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Pilot (probable cause); cases with it: [WSK PZL Mielec M-18A, 1 case](https://openairdocs.org/ntsb-findings/02061510/cases.md?model=9810103), [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md)
- [Parking/securing](https://openairdocs.org/ntsb-findings/01011000): Aircraft › Aircraft handling/service · Incorrect use/operation (probable cause); cases with it: [WSK PZL Mielec M-18A, 1 case](https://openairdocs.org/ntsb-findings/01011000/cases.md?model=9810103), [All aircraft, 11 cases](https://openairdocs.org/ntsb-findings/01011000/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Standing-engine(s) operating: Preflight or dispatch event](https://openairdocs.org/ntsb-events/030); cases with it: [WSK PZL Mielec M-18A, 2 cases](https://openairdocs.org/ntsb-events/030/sequence.md?model=9810103), [All aircraft, 355 cases](https://openairdocs.org/ntsb-events/030/sequence.md)
- [Standing-engine(s) operating: Ground handling event](https://openairdocs.org/ntsb-events/080) (defining event); cases with it: [WSK PZL Mielec M-18A, 1 case](https://openairdocs.org/ntsb-events/080/sequence.md?model=9810103), [All aircraft, 108 cases](https://openairdocs.org/ntsb-events/080/sequence.md)

## Analysis

The pilot reported he was taxing the airplane to the active runway when he realized the airplane's tail wheel lock was engaged. With the engine still running, the pilot set the parking brake, installed the control lock and exited the airplane with the intention of manually unlocking the tail wheel. When the pilot exited the cockpit he inadvertently knocked/pushed the throttle forward, to a high power setting, and the airplane started to roll across the taxiway. The unoccupied airplane accelerated, momentarily became airborne, and collided with an airport perimeter fence and terrain. The airplane sustained substantial damage to the fuselage, empennage and both wings. No pre accident mechanical malfunctions or failures were reported.

## Factual narrative

The commercial pilot reported he was taxing the airplane to the active runway when he realized the airplane's tail wheel lock was engaged. With the engine still running, the pilot set the parking brake, installed the control lock and exited the airplane with the intention of manually unlocking the tail wheel. When the pilot exited the cockpit he inadvertently knocked/pushed the throttle forward, to a high power setting, and the airplane started to roll across the taxiway. The unoccupied airplane accelerated, momentarily became airborne, and collided with an airport perimeter fence and terrain. The airplane sustained substantial damage to the fuselage, empennage and both wings. No pre accident mechanical malfunctions or failures were reported.

## Aircraft

- Registration: [N81705](https://openairdocs.org/deregistered/N81705-2017-05-31), registration cancelled 2017-05-31, S/N 1Z020-17 (OpenAirDocs)
- Reported make and model: WSK PZL MIELEC M-18A
- Registry model: [WSK PZL Mielec M-18A](https://openairdocs.org/model/wsk-pzl-mielec-m-18a) (registry code 9810103) (OpenAirDocs)
- Category: Airplane
- Serial number: 1Z020-17
- Airframe hours: 3733
- Engines: Pezetel ASZ-621R-M18 967 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: A-1 Aviation Inc
- Registered owner: A-1 Aviation Inc
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 14, 2008
- Departed: U76, Mountain Home, ID
- Destination: U76, Mountain Home, ID
- Airport: U76, Mountain Home Municipal Airpor, runway 10, 5,000 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 63; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2; seat: center; flight hours: 18,400 total, 5,000 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 110° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: none

## 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 20081108850769A](https://openairdocs.org/incident/20081108850769A), Nov 8, 2008: Wsk M18A, Mountain Home, ID, No damage. (-23) Pilot was taxiing for takeoff on runway 10 when he realized that the tailwheel lock would not disengage. The pilot decided to stop the aircraft on the…

## Other investigations on N81705 (2)

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 SEA02LA065](https://openairdocs.org/ntsb/SEA02LA065), Apr 8, 2002: WSK PZL Mielec M-18A (N81705), Rockford, WA, substantial damage. Probable cause: The pilot's inadequate pre-flight planning/decision to continue the takeoff. Contributing to the accident was the wind gusts.
- [NTSB SEA94LA201](https://openairdocs.org/ntsb/SEA94LA201), Jul 30, 1994: WSK PZL Mielec M18S (N81705), Royal City, WA, substantial damage. Probable cause: THE PILOT'S INADEQUATE REMEDIAL ACTION. FACTORS INCLUDE HIGH DENSITY ALTITUDE AND UNFAVORABLE WINDS.

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.