Air Tractor AT-502B N6146G
20 August 2002 · Rigby, Idaho, United States · Minor injuries
Summary
On 20 August 2002 at about 12:52 local time, a Air Tractor AT-502B registered N6146G was involved in an accident near Rigby, Idaho, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.
The record
- Date
- at 12:52
- Classification
- Accident
- Location
- Rigby, Idaho, United States
- Nearest airport
- Rigby-Jefferson County (U56)
- Coordinates
- 43.6333, -111.9167
- Aircraft
- Air Tractor AT-502B
- Registration
- N6146G
- Category
- Airplane
- Engines
- 1
- Operator
- Not recorded
- Operating rule
- Part 137: Agricultural
- Purpose of flight
- Aerial Application
- Phase of flight
- Not recorded
- Route
- Rigby → Unknown
- Aircraft damage
- Substantial
- Weather
- VMC
- Light
- Day
- NTSB number
- SEA02LA161
People
1 person had minor injuries.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 1 | 0 | 0 | 1 | 0 |
Probable cause
The failure of one or more compressor turbine blades resulting in a shutdown of the engine during initial climb resulting in a forced landing. Contributing factors were the eroded condition of the compressor turbine guide vane nozzles and the ditch which the aircraft encountered during the landing rollout.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
The pilot of the Air Tractor AT-502B had reported observing no abnormalities during engine start and the subsequent application of power during takeoff. Climbing through 100 feet he heard a loud "bang," observed sparks and flames exiting the engine exhaust ports and transitioned to a power off forced landing. As the aircraft was rolling out it encountered a ditch and the main landing gear separated. Post-crash examination of the engine revealed extensive damage to the blades of the compressor turbine disk and erosive burning damage to the vanes of the vane ring situated immediately upstream of the compressor turbine disk. The 22 year old Pratt & Whitney PT6A-34 turboshaft engine had a total of 7,070 hours since new and had undergone an undocumented overhaul 5,820 hours previously to the accident. The last hot section inspection referenced in the engine log occurred 2,871 hours previous to the accident and the last logged inspection was a 100-hour inspection 324 hours and eight months previous to the accident.
Quoted verbatim from the NTSB record.
Other Air Tractor AT-502B accidents
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 21 Aug 2002 | Air Tractor AT-502B | Rosenburg, Texas, United States | - | Fatal | - |
| 28 Feb 2002 | Air Tractor AT-502B | Extension, Louisiana, United States | Donald Goodman | Fatal | 1 |
| 12 Jun 2001 | Air Tractor AT-502B | Marvell, Arkansas, United States | - | Minor injuries | - |
| 22 Aug 2003 | Air Tractor AT-502B | Westside, Iowa, United States | Westerlin and Harrington Flying SER | Minor injuries | - |
| 19 Jun 2001 | Air Tractor AT-502B | Newport, Arkansas, United States | Name | No injuries | - |
| 19 May 2003 | Air Tractor AT-502B | Edna, Texas, United States | - | No injuries | - |
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 11 Aug 2002 | Piper PA-22/20 | Shearer, Idaho, United States | - | No injuries | - |
| 25 Sep 2002 | Piper PA-28-180 | Yellow Pine, Idaho, United States | - | Fatal | 2 |
| 12 Mar 2002 | Piper PA-31 | Atlanta, Idaho, United States | - | Fatal | 3 |
| 16 Jun 2002 | Stinson 108-1 | Heyburn, Idaho, United States | - | No injuries | - |
| 17 Aug 2002 | Beechcraft C-35 | Nampa, Idaho, United States | - | Serious injuries | - |
| 21 Sep 2002 | Cessna R172K | Salmon, Idaho, United States | - | No injuries | - |