# NTSB FTW83LA444: Clarks Pitt Special S1S, N2050, Manvel, TX, September 10, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 10, 1983, 16:00 local (21:00 UTC)
- Place: Manvel, TX
- Coordinates: 29.480211, -95.349868 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.4802&lon=-95.3499&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21064
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW83LA444
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21064/pdf
- Page: https://openairdocs.org/ntsb/FTW83LA444

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering
  - wing,wing rib - failure,partial (cause)
  - aerobatics - performed, pilot in command (cause)

## Analysis

THE ACFT BUFFETTED ABNORMALLY DURING AN AEROBATIC MANEUVER SO THE PLT RELAXED THE 'G' LOADING ON THE AIRFRAME. THE PLT NOTED A CONCAVE DEFORMITY IN THE BOTTOM OF THE LEFT UPPER WING. LEVEL FLT WAS ACHIEVED TO TEST THE FLT CHARACTERISTICS OF THE ACFT. FLT CONTROL SEEMED 'NEARLY NORMAL' SO A NORMAL LANDING WAS MADE. POST LANDING INVESTIGATION REVEALED SIX BROKEN RIBS IN THE LEFT UPPER WING.

## Aircraft

- Registration: N2050 (not matched to a registry record)
- Reported make and model: CLARKS PITT SPECIAL S1S
- Category: Airplane, amateur-built
- Serial number: 1001
- Airframe hours: 732
- Engines: LYCOMING IO-360 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: D.J. Rihn
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, June 1, 1983, 70 hours before
- Airport: 3TA1, Wolfe

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 54; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 7,200 total, 600 in this make and model, 7,000 as pilot in command, 115 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 81 °F

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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