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Accidents · NTSB ERA25LA079 · Final report

Air Tractor AT504 accident near Big Cypress, Florida, December 18, 2024

On December 18, 2024 at about 9:27 pm local time, a 2024 Air Tractor AT504, registered N8516V, was substantially damaged in an accident during enroute (descent) near Big Cypress, Florida. It was a ferry flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

The pilot’s decision to depart with cargo outside of the designated baggage compartment, which resulted in the cargo interfering with the rudder control system.

Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.

What the record shows

Date
December 18, 2024 · about 9:27 pm local time
Place
Big Cypress, Florida · map
Type
Accident
Injuries
No one was hurt; 1 person was on board or involved.
Weather
visual conditions (good weather)
Aircraft
Air Tractor AT504, built 2024
Registration
N8516V · no longer on the register · serial 504-4055
Damage
Substantial damage
Flight
Ferry flight · general aviation rules (Part 91)

The NTSB's narrative final · quoted from the NTSB record

During the first leg of a ferry flight the pilot reported that, while descending through 9,000 ft above ground level (agl), the airplane yawed left violently. Even with application of pressure to the right rudder pedal, the airplane continued in a left descending turn until impacting swampy terrain. The airplane sustained substantial damage to the left wing and engine mounts. Postaccident examination of the airplane revealed that a large amount of baggage and cargo had been zip-tied to the tubular metal fuselage structure aft of the baggage compartment and under the cockpit area. Multiple zip ties were found cut and others were found loose. The loose and cut zip ties were found in the vicinity and around a large piece of spray equipment that had been wrapped in plastic, as well as a box both, both of which could be moved by hand when pressure was applied. These items were in the vicinity of both the right rudder direct drive cable and the right rudder/aileron interconnect cable. The examination otherwise found no evidence of any preaccident mechanical malfunctions or failures of the airplane that would have precluded normal operation. Based on this information it is likely that the cargo shifted during the flight and interfered with the rudder control system, resulting in the rudder hard over. The weight and balance filled out by the pilot prior to the flight showed that he had accounted for cargo and baggage outside the airplane’s designated baggage compartment. While this showed that the airplane was likely being operated within its center of gravity envelope it, the pilot’s decision to operate the flight with cargo outside the designated area did not account for the potential that the cargo would shift in such a way that it could interfere with the flight controls.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record from the NTSB's investigation tables, in plain English

What happened, in order

  1. Off-field or emergency landing during enroute (descent)
  2. Aircraft loading event during prior to flight
  3. Flight control sys malf/fail during enroute (descent) defining event

The NTSB's findings

  • Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
  • Aircraft › Aircraft handling/service › Loading › (general) › Incorrect use/operation

Pilot

  • Certificate: commercial pilot
  • Ratings: single-engine land
  • Flight time: 5,844 hours in all; 6 in this make and model; 104 in the last 90 days; 65 in the last 30 days; 5,844 as pilot in command
  • Last flight review: July 12, 2023
  • Medical certificate: Class 2 (with waivers/limitations)
  • Seat: left
  • Injury: no injuries

The aircraft

  • Airframe total time: 11.9 hours
  • Maximum gross weight: 8,000 lb
  • Seats: 2
  • Landing gear: fixed
  • Engine: Pratt & Whitney Canada PT6A-34AG (turboprop); 12 hours total

The flight

  • Departed from: 50F Cresson TX at 2:30 pm
  • Destination: FXE Ft. Lauderdale FL
  • Flight plan: none

Weather at the time

  • Light: daylight
  • Visibility: 10 statute miles
  • Temperature: 32°F (0°C), dew point 32°F (0°C)
  • Altimeter: 30.02 inHg
  • Observation at 2:45 pm from IMM, 24 miles away

Weather report (METAR): METAR KIMM 182125Z AUTO 00000KT 10SM A3002 RMK AO2

Injuries

FatalSeriousMinorNone
Flight crew1

Photographs from the investigation 4 pictures from the NTSB's docket, as the NTSB released them

The NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.

Documents from the investigation the NTSB's docket: the evidence folder behind the report

11 documents, released by the NTSB on August 20, 2025. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.

The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.

Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.