Air Tractor INC AT-502B accident near Decatur, Illinois, July 11, 2022
On July 11, 2022 at about 11:30 am local time, a 2004 Air Tractor INC AT-502B, registered N5850R, was substantially damaged in an accident during takeoff near Decatur, Illinois (Decatur Airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 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
Fracture of the compressor turbine (CT) blades due to creep.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 11, 2022 · about 11:30 am local time
- Place
- Decatur, Illinois · Decatur Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor INC AT-502B, built 2004 · all AT-502Bs on the register
- Registration
- N5850R · no longer on the register · serial 502B-0685
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
During departure climbout for spray operations, the pilot heard a “pop” and observed white smoke trailing the airplane. The pilot made a forced landing, during which the airplane struck an airport perimeter fence that resulted in substantial damaged to both wings. Examination revealed that all compressor turbine (CT) rotor blades were fractured at varying spanwise locations. The power turbine (PT) rotor blades downstream of the CT blades exhibited impact damage and were fractured at varying spanwise locations. Metallurgical analysis of the CT blades revealed micro-voids were present along the material grain boundaries and rafting of the gamma prime which were indicative of creep. Metallurgical analysis of the CT blades revealed solutioning of the gamma prime which is consistent with exposure to temperature in excess of the engine operating limits. It was not determined if the exposure to elevated temperatures occurred before or during the event.
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
- Loss of engine power (total) during takeoff defining event
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Turbine section › Failure
Pilot
- Certificate: commercial pilot, private
- Ratings: single-engine land
- Flight time: 760 hours in all; 112 in this make and model; 37 in the last 90 days; 30 in the last 30 days; 684 as pilot in command
- Last flight review: January 14, 2021
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 5,975 hours
- Last inspection: annual inspection, November 16, 2021; 51 hours since
- Maximum gross weight: 8,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney Canada PT6A-34AG (turboprop); 5,975 hours total
- Operator: Adams Aerial Solutions LLC
The flight
- Departed from: DEC Decatur IL at 11:30 am
- Destination: DEC Decatur IL
- Flight plan: none
- Runway 6, 8,496 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 210° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 70°F (21°C), dew point 61°F (16°C)
- Altimeter: 29.90 inHg
- Observation at 6:54 am from KDEC, 1 miles away
Weather report (METAR): KDEC 111154Z 21008KT 10SM CLR 21/16 A2990 RMK AO2 SLP119 T02060156 10206 20183 58011
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
6 documents, released by the NTSB on February 21, 2024. 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.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 2 | Photos of Airplane at Accident Site | PDF, 2 pages | View Download |
| 3 | Powerplants Group Chair's Factual Report | PDF, 23 pages | View Download |
| 4 | Powerplants Attachment 1- Pwc Service Investigation Accident/incident Report No. 23ECN00007, Engine Accessories Investigation | PDF, 9 pages | View Download |
| 5 | Powerplants Attachment 2- Pwc Service Investigation Accident/incident Report No. 22-118, Materials Laboratory Analysis | PDF, 7 pages | View Download |
| 6 | Release of Aircraft Wreckage, NTSB Form 6120.15 | PDF, 1 page | View Download |
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.