# NTSB FTW91LA094: Pitts S1C, N48JP, Houston, TX, June 9, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 9, 1991, 12:00 local (17:00 UTC)
- Place: Houston, TX
- Coordinates: 29.830368, -95.660881 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.8304&lon=-95.6609&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 23341
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW91LA094
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23341/pdf
- Page: https://openairdocs.org/ntsb/FTW91LA094

## Probable cause

THE FAILURE OF THE PROPELLER DUE TO IMPROPER INSTALLATION.

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering
  - propeller system/accessories,blade - vibration
  - propeller system/accessories,blade - composite material
  - propeller system/accessories,blade - delamination (cause)
  - propeller system/accessories,blade - failure,total (cause)
  - maintenance,installation - improper, other maintenance personnel (cause)
  - propeller system/accessories,prop blade retention - improper (cause)
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - terrain condition - ditch
  - object - fence
- Nose over, landing - roll

## Analysis

FOLLOWING A SERIES OF AEROBATIC MANEUVERS TO TEST THE EFFECTIVENESS OF NEW TYPE OF COMPOSITE PROPELLER THE AIRPLANE EXPERIENCED A CATASTROPHIC FAILURE OF THE PROPELLER.  THE PROPELLER WAS ISSUED WITH A KIT THAT INCLUDED THE MOUNTING BOLTS. THE BOLTS PROVIDED WERE TOO LONG AND BOTTOMED OUT RESULTING IN NO TORQUE BEING APPLIED TO THE PROPELLER. THE PROPELLER WOBBLED, AND THE PROPELLER LAMINATIONS SEPARATED.

## Aircraft

- Registration: [N48JP](https://openairdocs.org/deregistered/N48JP-2013-06-27), registration cancelled 2013-06-27, S/N 072, built 1976 (OpenAirDocs)
- Reported make and model: PITTS S1C
- Registry model: [Plante PITTS SPECIAL S-1C](https://openairdocs.org/model/plante-pitts-special-s-1c) (registry code 7221130) (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: 072
- Engines: LYCOMING O-360-A3A 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Joseph A. Pacht

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial, flight instructor; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 1,065 total, 325 in this make and model, 982 as pilot in command, 30 in the last 90 days, 11 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 70° at 12 knots
- Visibility: 12 statute miles
- Lowest ceiling: 13,000 ft broken
- Temperature: 79 °F, dew point 72 °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 19910609020479A](https://openairdocs.org/incident/19910609020479A), Jun 9, 1991: Amtrpt PITTSSPECS1C, Houston, TX, Substantial damage. On test flight of new kevlar prop lost prop and spinner. Hit fence and flipped over on forced landing.

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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