# NTSB LAX94LA008: Stinson 108, Mesa, AZ, October 10, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 9, 1993, 17:19 local (Oct 10, 1993, 00:19 UTC)
- Place: Mesa, AZ
- Coordinates: 33.429706, -111.709777 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.4297&lon=-111.7098&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report August 1, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 28566
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA008
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28566/pdf
- Page: https://openairdocs.org/ntsb/LAX94LA008

## Probable cause

a loose wheel half bolt, due to the inadequate maintenance inspection of the aircraft.

## Sequence of events

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

- Loss of control - on ground/water, landing - flare/touchdown
  - landing gear,wheel - jammed (cause)
  - maintenance,inspection - inadequate, other maintenance personnel (cause)
  - directional control - not possible, pilot in command
  - ground loop/swerve - inadvertent, pilot in command
- Nose over, landing - roll
  - terrain condition - soft

## Analysis

The pilot reported that just after touchdown the aircraft 'immediately darted to the left.' The pilot was unsuccessful in regaining directional control and the aircraft ground looped off the right side of the runway. As the aircraft entered the dirt area next to the runway pavement, the aircraft nosed over onto its back. An FAA airworthiness inspector examined the aircraft and reported that one of the three bolts which secures the left wheel halves together had backed out of its associated lock nut. The protruding bolt head contacted the brake caliper and subsequently locked the wheel. An examination of the maintenance records revealed that the wheel halves were last split about two years prior to the accident when a new tire was installed.

## Factual narrative

On October 9, 1993, at 1719 mountain standard time, a Stinson 108, NC409, nosed over during landing roll out at Falcon Field, Mesa, Arizona.  The aircraft was owned and operated by the pilot and was on a personal cross country flight.  Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation.  The aircraft sustained substantial damage.  The certificated private pilot and his one passenger were not injured.  The flight originated at Marana, Arizona, on the day of the mishap about 1500 hours and had made an enroute fuel stop at Chandler, Arizona.

In his written statement, the pilot reported that just after touchdown the aircraft "immediately darted to the left."  The pilot was unsuccessful in regaining directional control and the aircraft ground looped off the right side of the runway.  As the aircraft entered the dirt area next to the runway pavement, the aircraft nosed over onto its back.

An FAA airworthiness inspector examined the aircraft and reported that one of the three bolts which secures the left wheel halves together had backed out of its associated lock nut.  The protruding bolt head contacted the brake caliper and subsequently locked the wheel.  An examination of the maintenance records revealed that the wheel halves were last split about two years prior to the accident when a new tire was installed.

## Aircraft

- Registration: NC409 (not matched to a registry record)
- Reported make and model: STINSON 108
- Category: Airplane
- Serial number: 108-157
- Airframe hours: 1407
- Engines: FRANKLIN 6A4-150-B3 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Thomas R. Blair
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 23, 1993, 35 hours before
- Departed: P10, CHANDLER, AZ
- Destination: FFZ
- Airport: FFZ, Falcon Field, runway 22L, 5,100 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 53; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 384 total, 217 in this make and model, 297 as pilot in command, 16 in the last 90 days, 4 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 50 statute miles
- Lowest ceiling: none
- Altimeter: 29.00 inHg
- Observed at: FFZ

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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