# NTSB WPR13CA412: Piper PA 11, N4988M, Bozeman, MT, September 16, 2013

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Data collection · Final report
- Date: September 16, 2013, 14:20 local (20:20 UTC)
- Place: Bozeman, MT
- Coordinates: 45.779167, -111.155555 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.7792&lon=-111.1556&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Defining event: [Taxi: Roll over](https://openairdocs.org/ntsb-events/097)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report November 19, 2013
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- NTSB case key (mKey): 88059
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR13CA412
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88059/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88059
- Page: https://openairdocs.org/ntsb/WPR13CA412

## Probable cause

The pilot's failure to maintain aircraft control and inadequate compensation for the high gusty wind conditions during taxi.

## Findings

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

- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-11, 11 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101102), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-11, 1 case](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=7101102), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md)
- [Wind: high wind](https://openairdocs.org/ntsb-findings/03034055): Environmental issues › Conditions/weather/phenomena · Not specified; cases with it: [Piper PA-11, 1 case](https://openairdocs.org/ntsb-findings/03034055/cases.md?model=7101102), [All aircraft, 112 cases](https://openairdocs.org/ntsb-findings/03034055/cases.md)

## Sequence of events

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

- [Taxi: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Piper PA-11, 2 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=7101102), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md)
- [Taxi: Roll over](https://openairdocs.org/ntsb-events/097) (defining event); cases with it: [Piper PA-11, 1 case](https://openairdocs.org/ntsb-events/097/sequence.md?model=7101102), [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md)

## Analysis

The pilot reported that after aborting the takeoff due to an approaching thunderstorm and high wind, while taxiing back to the parking area, a strong wind lifted the airplane. The airplane subsequently nosed over which resulted in substantial damage to the wings, fuselage, vertical stabilizer, and rudder. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.

## Factual narrative

The pilot reported that after aborting the takeoff due to an approaching thunderstorm and high winds, while taxiing back to the parking area, a strong wind lifted the airplane. The airplane subsequently nosed over which resulted in substantial damage to the wings, fuselage, vertical stabilizer, and rudder. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.

## Aircraft

- Registration: [N4988M](https://openairdocs.org/aircraft/N4988M), registered now, S/N 11-476, built 1948 (OpenAirDocs)
- Reported make and model: PIPER PA 11 (NO SERIES)
- Registry model: [Piper PA-11](https://openairdocs.org/model/piper-pa-11) (registry code 7101102) (OpenAirDocs)
- Registry engine: [Continental C90 series](https://openairdocs.org/engine/continental-c90-series) (registry code 17009, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 11-476
- Year built: 1948
- Engines: CONT MOTOR C90 SERIES 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Departed: KBZN, Bozeman, MT
- Destination: KBZN, Bozeman, MT
- Airport: KBZN, Bozeman Yellowstone Internatio

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; injuries: minor; flight instructor, commercial, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; seat: right; flight hours: 28,000 total
- Student pilot; age 73; injuries: none; student; seat: left

## Weather

- Conditions: Visual (VMC), Day
- Wind: 230° at 27 knots, gusting 42
- Visibility: 6 statute miles
- Lowest ceiling: 9,500 ft broken
- Temperature: 73 °F, dew point 46 °F
- Altimeter: 29.93 inHg
- Observed at: KBZN

## 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 20130916018899A](https://openairdocs.org/incident/20130916018899A), Sep 16, 2013: Piper PA-11, Bozeman, MT, Substantial damage. On September 16, 2013 at 1430 MST. A Piper PA-11, N4988M. After cancelling a request to take off, was returning to hanger was hit by a heavy gust of wind which…

## Docket (2 files)

The files NTSB released with the investigation on November 8, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88059. 774 KB in all.

- NTSB-Witness Statement (item 1, .PDF, 326 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40403654&FileExtension=.PDF&FileName=NTSB-Witness%20Statement-Redacted.PDF
- Accident Scene Photo (item 2, .PDF, 448 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40402467&FileExtension=.PDF&FileName=Accident%20Scene%20Photo-Master.PDF

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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