# NTSB ATL83LA181: Pitts S1-SP, N44GP, Wetumpka, AL, May 8, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 8, 1983, 13:30 local (18:30 UTC)
- Place: Wetumpka, AL
- Coordinates: 32.539752, -86.199821 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.5398&lon=-86.1998&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6062
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL83LA181
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6062/pdf
- Page: https://openairdocs.org/ntsb/ATL83LA181

## 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 - disintegrated (contributing factor)
  - aerobatics - performed, pilot in command (cause)
  - acft/equip,inadequate airframe, production/design personnel (cause)
  - wing,skin - separation (contributing factor)
  - design stress limits of aircraft - exceeded, pilot in command (cause)
  - design stress limits of aircraft - inaccurate, production/design personnel (cause)

## Analysis

THE ACFT EXPERIENCED AN INFLT STRUCTURAL FAILURE OF ITS UPPER WING DURING AEROBATICS IN AN AIR SHOW. THE ACFT WAS LANDEDSAFELY AND THE PILOT WAS NOT INJURED. THE UPPER WING LEADING EDGE RIBS REPORTEDLY COLLAPSED AS THE PILOT BEGAN TO PULL UP AT THE BEGINNING OF AN EIGHT-SIDED LOOP AT ABOUT 200 KTS. AN FAA OBSERVER REPORTED THAT ABOUT 60% OF THE UPPER WING FABRIC THEN PEELED REARWARD AND SEPARATED. THE PILOT 'ABORTED THE SHOW' AND LANDED WITHOUT FURTHER INCIDENT. EXAMINATION BY AN FAA INSPECTOR AND THE OWNER REVEALED THAT THE LEADING EDGE OF THE UPPER WING HAD COLLAPSED REARWARD TOTHE FRONT SPAR WITH ALL NOSE RIBS BROKEN. THIS ACFT IS ONE OF TWO WITH 'KERMIT WEEKS' WINGS. THE FAILURE DESCRIBED HAS ALSO HAPPENED WITH THE OTHER ACFT. BOTH ACFT UPPER WINGS HAD BEEN CONSTRUCTED OF LIGHTER WEIGHT MATERIALS WITH EMPHASIS ON IMPROVED PERFORMANCE. SUBSEQUENT TO THIS ACCIDENT THE WING WAS REBUILT WITH STRONGER MATERIALS TO WITHSTAND HIGHER LOADS.

## Aircraft

- Registration: N44GP (not matched to a registry record)
- Reported make and model: PITTS S1-SP
- Category: Airplane, amateur-built
- Serial number: 001
- Airframe hours: 385
- Engines: LYCOMING IO-360 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 91
- Registered owner: Clarence G. Parramore
- Last inspection: Annual, April 1, 1983
- Departed: 08A
- Airport: 08A, Wetumpka Muni., runway 27, 3,000 × 80 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; commercial, flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: front; flight hours: 14,812 total, 1,090 in this make and model, 14,512 as pilot in command, 53 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 81 °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 19830508018299A](https://openairdocs.org/incident/19830508018299A), May 8, 1983: Amtrpt PITTSSPECS1, Wetumpka, AL, Substantial damage. Upper wing collapsed rearward to wing front spar during airshow routine. Pilot made safe landing afterward.

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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