# NTSB MIA89LA112: Waco UPF-7, N39752, Marathon, FL, March 21, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 21, 1989, 14:30 local (19:30 UTC)
- Place: Marathon, FL
- Location: 24.7263° N, 81.0514° W: Placed by OpenAirDocs at THE FLORIDA KEYS MARATHON INTL (MTH), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=24.7263&lon=-81.0514&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report April 24, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 32412
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA89LA112
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/32412/pdf
- Page: https://openairdocs.org/ntsb/MIA89LA112

## Probable cause

THE PILOT FAILED TO MAINTAIN DIRECTIONAL CONTROL OF THE AIRCRAFT AND INADVERTENTLY ALLOWED IT TO GROUND LOOP. CROSSWIND WAS A CONTRIBUTING FACTOR.

## 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
  - weather condition - crosswind (contributing factor)
  - directional control - not maintained, pilot in command (cause)
  - ground loop/swerve - inadvertent, pilot in command (cause)
- Main gear collapsed, landing - roll
  - landing gear,main gear - overload

## Analysis

WHILE LANDING ON RWY 7, THE PLT LOST DIRECTIONAL CONTROL OF THE ACFT. SUBSEQUENTLY, IT GROUND LOOPED TO THE RIGHT & THE LEFT MAIN GEAR COLLAPSED. ABOUT 40 MI WSW AT KEY WEST, FL, THE WIND WAS FROM 140 DEG AT 13 KTS.

## Aircraft

- Registration: [N39752](https://openairdocs.org/aircraft/N39752), registered now, S/N 5885, built 1942 (OpenAirDocs)
- Reported make and model: WACO UPF-7
- Registry model: [Waco UPF-7](https://openairdocs.org/model/waco-upf-7) (registry code 9601302) (OpenAirDocs)
- Registry engine: [Jacobs R-755A2M](https://openairdocs.org/engine/jacobs-r-755a2m) (registry code 35020, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 5885
- Engines: CONTINENTAL W-670-K 225 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Conch Classic Air Tours
- Registered owner: Pegasus Air, Inc
- Airworthiness certificate: Standard, Normal
- Airport: MTH, Marathon, runway 7, 5,000 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 2,500 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 140° at 13 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 82 °F, dew point 68 °F
- Altimeter: 30.00 inHg
- Observed at: EYW, 40 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 19890321033189A](https://openairdocs.org/incident/19890321033189A), Mar 21, 1989: Waco UPF7, Marathon, FL, Substantial damage. Ground looped on landing roll collapsed left main gear.

## Other investigations on N39752 (1)

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 NYC89LA180](https://openairdocs.org/ntsb/NYC89LA180), Aug 2, 1989: Waco UPF-7 (N39752), Plymouth, NH, substantial damage. Probable cause: LOSS OF DIRECTIONAL CONTROL DURING AN ABORTED TAKEOFF. THE DITCH WAS A RELATED FACTOR.

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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