# NTSB MIA94LA171: Pitts S2B, N61PS, Fort Lauderdale, FL, July 4, 1994

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 4, 1994, 14:00 local (18:00 UTC)
- Place: Fort Lauderdale, FL
- Location: 26.1223° N, 80.1434° W: Placed by OpenAirDocs: center of Fort Lauderdale, FL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=26.1223&lon=-80.1434&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report April 27, 1995
- Report: Approved by Office Director
- NTSB case key (mKey): 37570
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA94LA171
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/37570/pdf
- Page: https://openairdocs.org/ntsb/MIA94LA171

## Probable cause

THE POOR WELDING QUALITY OF THE MANUFACTURER, RESULTING IN THE FATIGUE FAILURE OF THE AILERON ATTACHMENT BRACKET.

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering
  - flight control,aileron attachment - fatigue (cause)
  - aircraft/equipment inadequate, manufacturer (cause)

## Analysis

THE PILOT WAS PERFORMING ACROBATIC MANEUVERS WHEN HE HEARD A 'POP' AND NOTED THAT HIS RIGHT UPPER AILERON WAS LOOSE. HE SLOWED DOWN, AND WAS ABLE TO RETURN AND LAND WITHOUT FURTHER INCIDENT. POSTFLIGHT INSPECTION REVEALED A FAILURE OF THE UPPER RIGHT INBOARD AILERON WELDED BRACKET. FURTHER METALLURGICAL EXAMINATION AT THE SAFETY BOARD LABORATORY REVEALED 3 DISTINCT FATIGUE ORIGINS BETWEEN THE TOE OF THE WELD AND THE WELDED ZONES. THE WELD ITSELF EXHIBITED SHARP AND HIGH WELD CROWNS.

## Factual narrative

On July 4, 1994, about 1400 eastern daylight time, N61PS, a Pitts S2B, registered to the pilot David Swartz, experienced an in-flight control system failure while maneuvering on a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The airplane was substantially damaged and the pilot was not injured. The flight originated about 1330 the same day.

The pilot stated that while performing aerobatics he heard a "pop". He then noticed partial loss of control of aileron travel. He returned to the airport and landed without further incident. Postflight inspection of the airplane revealed a failure of the upper, right, inboard aileron welded bracket. This same airplane experienced longeron failures at the welds on May 26, 1994, reference, NTSB accident case number MIA94LA154.

The failed aileron bracket was submitted to the NTSB laboratory for examination. The examination revealed three distinct fatigue origins between the toe of the weld and the welded zones. The weld itself exhibited sharp and high weld crowns.

## Aircraft

- Registration: [N61PS](https://openairdocs.org/aircraft/N61PS), registered now, S/N 5230, built 1991 (OpenAirDocs)
- Reported make and model: PITTS S2B
- Registry model: [Aviat PITTS S-2B](https://openairdocs.org/model/aviat-pitts-s-2b) (registry code 2210308) (OpenAirDocs)
- Registry engine: [Lycoming AEIO-540 series](https://openairdocs.org/engine/lycoming-aeio-540-series) (registry code 41568, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 5230
- Airframe hours: 740
- Engines: LYCOMING AEIO-540 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Swartz, David J.
- Airworthiness certificate: Standard, Aerobatic
- Last inspection: Annual, December 15, 1993, 160 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 46; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: rear; flight hours: 879 total, 374 in this make and model, 741 as pilot in command, 40 in the last 90 days, 23 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 100° at 15 knots
- Visibility: 15 statute miles
- Lowest ceiling: 20,000 ft broken
- Altimeter: 30.00 inHg
- Observed at: FXE, 15 nm away

## Other investigations on N61PS (2)

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.

- [NTSB MIA04CA055](https://openairdocs.org/ntsb/MIA04CA055), Mar 3, 2004: Aviat Pitts S2B (N61PS), Parkland, FL, substantial damage. Probable cause: The pilot's inadequate preflight planning which resulted in an off-airport precautionary landing to preclude fuel exhaustion, which resulted in damage to the airplane during the landing.
- [NTSB MIA94LA154](https://openairdocs.org/ntsb/MIA94LA154), May 26, 1994: Pitts S2B (N61PS), Keystone Height, FL, substantial damage. Probable cause: THE PILOT-IN-COMMAND'S EXCEEDING OF THE DESIGN LIMITATIONS OF THE AIRPLANE.

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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