# NTSB CHI89DEM07: Bradley S-1D, N787PA, Mt Pleasant, MI, August 27, 1989

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: August 27, 1989, 18:45 local (22:45 UTC)
- Place: Mt Pleasant, MI
- Coordinates: 43.589363, -84.769371 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.5894&lon=-84.7694&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report June 30, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 14199
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI89DEM07
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14199/pdf
- Page: https://openairdocs.org/ntsb/CHI89DEM07

## Probable cause

THE TAIL WHEEL SPRING BECOMING DISCONNECTED RESULTING IN THE PILOT'S INABILITY TO MAINTAIN DIRECTIONAL CONTROL OF THE AIRPLANE.

## 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
  - landing gear,tailwheel assembly - disconnected (cause)
  - landing gear,tailwheel - vibration
  - directional control - not possible, pilot in command (cause)
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - ditch

## Analysis

A SEVERE TAIL WHEEL SHIMMY WAS EXPERIENCED DURING THE LANDING ROLL. DIRECTIONAL CONTROL WAS LOST AND THE AIRPLANE TRAVELED OFF THE SIDE OF THE RUNWAY WHERE IT CONTACTED A DITCH. DURING THE INVESTIGATION, THE LEFT SIDE TAIL WHEEL SPRING WAS FOUND ON THE RUNWAY. THE RIGHT SIDE SPRING REMAINED ATTACHED TO THE RUDDER, BUT WAS DISCONNECTED AT THE TAIL WHEEL STEERING HORN.

## Aircraft

- Registration: [N787PA](https://openairdocs.org/deregistered/N787PA-1995-03-02), registration cancelled 1995-03-02, S/N 724H (OpenAirDocs)
- Reported make and model: BRADLEY S-1D
- Registry model: [Bradley J Max PITTS SPECIAL S 1D](https://openairdocs.org/model/bradley-j-max-pitts-special-s-1d) (registry code 7221234) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 724H
- Airframe hours: 116
- Engines: LYCOMING IO-320-E2A 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Thimothy W Slavens
- Registered owner: J. Max Bradley
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, October 28, 1988, 33 hours before
- Departed: MOP
- Airport: MOP, Mt Pleasant Muni, runway 27, 5,000 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 27; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: center; flight hours: 419 total, 40 in this make and model, 390 as pilot in command, 35 in the last 90 days, 14 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 7 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 77 °F, dew point 66 °F
- Altimeter: 30.00 inHg
- Observed at: GRR, 58 nm away

## 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 19890827031929A](https://openairdocs.org/incident/19890827031929A), Aug 27, 1989: Amtrpt PITTSSPECIAL, Mount Pleasant, MI, Substantial damage. Tail wheel spring broke on landing. Caused a bad shimmy. Lost control veered off runway and struck a ditch bank.

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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