# NTSB MIA92LA096: Ankerman, Donald L. SX300, N11AG, Okeechobee, FL, March 11, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Limited investigation · Final report
- Date: March 11, 1992, 14:44 local (19:44 UTC)
- Place: Okeechobee, FL
- Coordinates: 27.239345, -80.820953 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=27.2393&lon=-80.8210&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report August 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 33075
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA92LA096
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/33075/pdf
- Page: https://openairdocs.org/ntsb/MIA92LA096

## Probable cause

FAILURE OF THE PILOT-IN-COMMAND TO MAINTAIN AIRSPEED (VS) RESULTING IN INADVERTENT STALL/MUSH.

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - airspeed(vs) - not maintained, pilot in command (cause)
  - stall/mush - inadvertent, pilot in command
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - water

## Analysis

A WITNESS STATED THAT HE OBSERVED THE AIRPLANE ROLL INTO A 90 DEGREE BANK ANGLE TO THE RT THEN OBSERVED IT DESCENDING NOSE & LT WING LOW UNTIL IMPACT WITH THE WATER.  HE FURTHER STATED THAT THE ENGINE WAS RUNNING NORMALLY UNTIL IMPACT. ALL COMPONENTS OF THE AIRPLANE WERE RECOVERED WITH THE EXCEPTION OF THE INBOARD SECTION OF THE LEADING EDGE OF THE LT WING. NO WITNESS REPORTED SEEING ANY OBJECT FALLING OFF THE AIRPLANE BEFORE IMPACT.  EXAMINATION OF THE AIRPLANE REVEALED NO EVIDENCE OF FLIGHT CONTROL FAILURE OR MALFUNCTION.

## Aircraft

- Registration: [N11AG](https://openairdocs.org/deregistered/N11AG-2013-10-29), registration cancelled 2013-10-29, S/N FAI11, built 1991 (OpenAirDocs)
- Reported make and model: ANKERMAN, DONALD L. SX300
- Registry model: [Ankerman Donald L SWEARINGEN SX300](https://openairdocs.org/model/ankerman-donald-l-swearingen-sx300) (registry code 8800010) (OpenAirDocs)
- Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: FAI-11
- Airframe hours: 44
- Engines: LYCOMING IO-540-L1C5 300 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Flying Ankers, Inc.
- Registered owner: Flying Ankers, Inc.
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Unknown, January 2, 2000
- Departed: LNA, WEST PALM BEACH, FL
- Airport: OBE, Okeechobee County

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 55; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 1,779 total, 44 in this make and model, 1,653 as pilot in command, 10 in the last 90 days, 2 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: 18,000 ft broken
- Temperature: 75 °F, dew point 72 °F
- Altimeter: 29.00 inHg
- Observed at: PBI, 51 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 19920311005829A](https://openairdocs.org/incident/19920311005829A), Mar 11, 1992: Amtres SX300, Okeechobee, FL, Destroyed, 2 fatal. Observed to stall in steep 360 for traffic spacing. Spun into a canal. Part of wing and stabilizer missing.

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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