# NTSB DCA82IA021: Gates Learjet 24B, N721J, Ft. Myer, FL, May 12, 1982

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: May 12, 1982, 18:54 local (22:54 UTC)
- Place: Ft. Myer, FL
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report May 12, 1983
- Report: Approved by Office Director
- NTSB office: Major Investigations Division
- NTSB case key (mKey): 71954
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA82IA021
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/71954/pdf
- Page: https://openairdocs.org/ntsb/DCA82IA021

## Sequence of events

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

- Airframe/component/system failure/malfunction, climb - to cruise
  - autopilot/flight director - failure,partial (contributing factor)
  - autopilot - not understood, pilot in command (cause)
- Loss of control - in flight, climb - to cruise

## Analysis

WHILE CLIMBING TO A CRUISE ALTITUDE OF 41000 FEET, THE PILOT ENGAGED THE AUTOPILOT AT APPROXIMATELY 29500 FEET. THE AIRCRAFT STARTED TO PITCH NOSE DOWN SEVERAL SECONDS LATER. THE PITCH TRIM SWITCH WAS TURNED OFF AND THE CIRCUIT BREAKERS PULLED. THE PILOTS WERE AIDED BY A PASSENGER AND USED ALL THEIR STRENGTH TO PULL BACK ON THE CONTROL WHEEL TO KEEP THE AIRCRAFT FROM CONTINUING TO PITCH NOSEDOWN. THE AIRCRAFT LANDED SAFELY. EXAMINATION OF AUTO- PILOT REVEALED THAT AN OVERVOLTAGE CONDITION EXISTED THAT WAS DRIVING THE STAB TRIM ACTUATOR TO THE AIRPLANE NOSE DOWN POSITION. IN ADDITION, THIS CAUSED THE AUTOPILOT EFFORT INDICATOR TO SHOW A MAXIMUM NOSE DOWN DEFLECTION. ACCORDING TO THE COPILOT'S STATEMENT, THE EFFORT INDICATOR WAS AT MAXIMUM DEFLECTION DURING THE PRE-TAKEOFF CHECK.

## Aircraft

- Registration: N721J (not matched to a registry record)
- Reported make and model: GATES LEARJET 24B
- Category: Airplane
- Serial number: 24B-200
- Airframe hours: 5056
- Engines: GEN.ELECTRIC GE610-4 2850 lbs thrust turbo jet
- Damage: No damage
- Flight: Business, Part 91
- Operator: Delaware Victor Air Service
- Registered owner: Delaware Victor Air Service
- Departed: AI, PBI
- Destination: AI, IAH
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: helicopter, airplane; medical: class 1, valid medical--no waivers/lim.; flight hours: 7,800 total, 1,200 in this make and model, 74 as pilot in command, 25 in the last 90 days, 7 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 5° at 1 knots
- Visibility: 10 statute miles
- Temperature: 46 °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).

- [Incident 19820512022999I](https://openairdocs.org/incident/19820512022999I), May 12, 1982: Lear 24B, Ft Myers, FL. Runaway trim on climb. Both pilots and passenger pulled nose up from dive. Disabled auto pilot. Snychronizer defect

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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