# NTSB DEN89LA179: Piper PA-18-135, N9967Q, Boulder, CO, July 25, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 25, 1989, 13:00 local (19:00 UTC)
- Place: Boulder, CO
- Coordinates: 40.020004, -105.250602 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.0200&lon=-105.2506&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report June 28, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 17753
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN89LA179
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17753/pdf
- Page: https://openairdocs.org/ntsb/DEN89LA179

## Probable cause

FAILURE OF THE PILOT TO MAINTAIN DIRECTIONAL CONTROL, WHICH RESULTED IN AN INADVERTENT GROUND SWERVE AND SUBSEQUENT DAMAGE TO THE WING.

## Sequence of events

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

- Loss of control - on ground/water, landing - roll
  - directional control - not maintained, pilot in command (cause)
  - ground loop/swerve - inadvertent, pilot in command (cause)
- Dragged wing,rotor,pod,float or tail/skid, landing

## Analysis

THE PLT RPRTD HE MADE A WHEEL LANDING ON RWY 8 WITH WINDS THAT HE ESTIMATED WERE LIGHT & VARIABLE.  HE SAID THAT DURING THE LANDING ROLL, THE PLANE SWERVED TO THE RIGHT.  HE ATTEMPTED TO CORRECT THE SWERVE, BUT TO NO AVAIL. THE LEFT WING STRUCK THE GROUND BETWEEN THE RWY & TWY.  DURING THE OCCURRENCE, THE LEFT WING SPAR WAS BENT & THE MAIN LANDING GEAR WAS DAMAGED, BUT THE PLT WAS ABLE TO TAXI THE PLANE TO THE HANGAR.

## Aircraft

- Registration: [N9967Q](https://openairdocs.org/aircraft/N9967Q), registered now, S/N 18-4012, built 1954 (OpenAirDocs)
- Reported make and model: PIPER PA-18-135
- Registry model: [Piper PA-18-135](https://openairdocs.org/model/piper-pa-18-135) (registry code 7101820) (OpenAirDocs)
- Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 18-4012
- Engines: LYCOMING O-290-D2 135 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Dakota Ridge Aviation, Inc.
- Registered owner: Unknown
- Departed: 3V5, FORT COLLINS, CO
- Destination: 1V5
- Airport: IV5, Boulder, runway 8, 4,100 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; flight hours: 420 total, 40 in this make and model, 340 as pilot in command, 130 in the last 90 days, 60 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 81 °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 19890725028719A](https://openairdocs.org/incident/19890725028719A), Jul 25, 1989: Piper PA18135, Boulder, CO, Substantial damage. Lost control and ground looped the tail wheel aircraft during landing roll.

## Other investigations on N9967Q (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 SEA02LA094](https://openairdocs.org/ntsb/SEA02LA094), Jun 2, 2002: Piper PA-18-135 (N9967Q), Payette, ID, substantial damage. Probable cause: The pilot's failure to adequately compensate for the wind conditions during landing resulting in a ground loop/swerve. Wind gusts were a contributing factor.
- [NTSB FTW97LA017](https://openairdocs.org/ntsb/FTW97LA017), Oct 12, 1996: Piper PA-18-135 (N9967Q), Boulder, CO, substantial damage. Probable cause: the pilot's failure to maintain directional control and his improper use of rudder. A factor was the pilot's lack of total experience in the make and model of airplane.

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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