Ayres S2R-T34 accident near Thornton, Mississippi, September 26, 1990
On September 26, 1990 at about 2:14 pm local time, a Ayres S2R-T34, registered N4017B, was destroyed in an accident near Thornton, Mississippi. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE IMPROPER DRILLING OF A HOLE IN THE SPAR CAP BY A MECHANIC RESULTING IN THE INITIATION OF FATIGUE CRACKING IN THE SPAR CAP AND SUBSEQUENT FAILURE OF THE SPAR CAP AND INFLIGHT SEPARATION OF THE WING.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 26, 1990 · about 2:14 pm local time
- Place
- Thornton, Mississippi
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Ayres S2R-T34
- Registration
- N4017B · registry record · serial T34-002
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
AIRPLANE EXPERIENCED SEPARATION OF RIGHT WING WHILE PULLING UP FROM AGRICULTURAL SPRAYING RUN. WING SEPARATED DUE TO FATIGUE FAILURE OF THE BOTTOM SPAR CAP WHICH WAS THE RESULT OF A HOLE BEING DRILLED INTO THE CAP. THE HOLE APPEARS TO HAVE BEEN DRILLED INTO THE CAP DURING INSTALLATION OF A WING MOUNTED AIR CONDITIONING COMPRESSOR, SIX YEARS AND 4,130 FLIGHT HOURS BEFORE THE FAILURE. THE AIR CONDITIONING UNIT WAS REMOVED 10 MONTHS LATER AND A PATCH WAS PLACED OVER THE AREA THE HOLE HAD BEEN DRILLED IN SPAR CAP. THE HOLE WOULD NOT HAVE BEEN VISIBLE DURING INSPECTION UNLESS MECHANIC REMOVED PATCH.
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
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 27,500 hours in all; 3,200 in this make and model; 500 in the last 90 days; 125 in the last 30 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 5,592 hours
- Last inspection: annual inspection, May 7, 1990; 491 hours since
- Maximum gross weight: 8,200 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W PT6A-34AG (turboprop); 0 hours total
The flight
- Departed from: 87I Yazoo City MS at 2:05 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 190° at 5 knots
- Visibility: 7 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 54°F (12°C)
- Altimeter: 30.00 inHg
- Observation at 1:52 pm from GWO, 25 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.