History of Flight
On April 18, 2016, about 0910 central daylight time, an Air Tractor Inc AT-502 airplane, registration N301LA, impacted terrain during spray operations near Kilbourne, Louisiana. The pilot was fatally injured, and the airplane was destroyed. The aircraft was registered to and operated by Pioneer Flying Service, Inc., under 14 CFR Part 137 as an aerial application flight. Day visual meteorological conditions prevailed, and no flight plan was filed. The local flight departed a private airport about 0900.
According to operator personnel, the pilot was conducting his second load of spray operations for the day to a farm area about 1/4 mile north of the accident site. A witness near the accident noticed the airplane enter a rapid descent while in a turn until it impacted the ground. A post-crash fire ensued.
The farmer whose field was being sprayed stated the pilot was "dressing up" a field with a tight area shaped like a bull nose, with trees at the end. The farmer did not witness the accident but noted the pilot was able to spray tight areas that other pilots avoided.
Personnel Information
The pilot, age 48, held a commercial pilot certificate with an airplane single-engine land rating and a second-class medical certificate issued June 1, 2015, with the restriction that he must wear corrective lenses for near vision. His last flight review was March 15, 2016.
Aircraft Information
The single-engine low-wing conventional-geared airplane was equipped with a Pratt and Whitney PT6A-34AG turboprop engine. According to the operator, the last annual inspection was performed on February 17, 2016. The airframe total time was 9,585 hours, and the engine total time was 7,022 hours, with 445 hours since the last hot section inspection.
Meteorological Information
At 0915, a weather observation station at Morehouse Memorial Airport (BQP), Bastrop, Louisiana, about 32 miles southwest of the accident site, reported: wind 080 degrees at 4 knots, visibility 10 miles, clear skies, temperature 19°C, dew point 15°C, and altimeter setting 30.24 inches of mercury.
Wreckage and Impact Information
The airplane impacted a soft open field. Other than electrical lines, no obstacles were in the immediate area. There was no evidence of in-flight impact with wires, trees, or other obstacles. The wooded area near the sprayed field was searched for broken branches without finding any.
The wreckage was confined to the impact site. The impact crater contained engine cowling, windshield plexiglass, and the hopper top and lid. The engine penetrated about 3 feet into the soft soil. Radiating from the crater were soil impressions consistent with impact marks from the leading edges of both wings. The wings were found about 10 feet away; both were crushed aft, with the left wing more damaged. The aft fuselage and rudder showed signs of momentum toward the left side. The impact marks and wreckage were consistent with a steep, nose-down impact at low groundspeed. The fuselage was largely destroyed by impact forces and post-crash fire.
All control surfaces were identified except the vertical stabilizer. Only a short piece of the stabilizer rear spar remained attached to the lower rudder. The rudder's lower hinge point was intact with minimal damage. The end of the wire deflector cable, normally attached to the stabilizer top, was found under the cockpit wreckage. Multiple fire-damaged aluminum pieces were possibly vertical stabilizer components but none could be confirmed. A witness mark on the top fuselage skin corresponded to the vertical stabilizer's leading edge.
Wing flaps were full up. Flight control continuity was confirmed to the extent possible; several components were consumed by fire or cut during the pilot's extrication. The aileron/rudder interconnect system had been removed.
The engine was damaged by post-crash fire, with the inlet case fractured and the accessories gearbox completely separated. Rotational signatures were observed in the compressor and power turbines, consistent with the engine under power during impact. No pre-impact anomalies of the engine, airframe, or propeller were found. Data from a GPS unit could not be downloaded due to fire damage.
Medical and Pathological Information
During his last medical examination, the pilot reported heterophoria, previous treatment for a kidney stone, and long-standing hypertension. He used nisoldipine, valsartan, and hydrochlorothiazide for blood pressure; none are generally impairing.
Autopsy by the West Carroll Parish Coroner's Office listed cause of death as multiple blunt force injuries and manner as accident. The heart weighed 550 grams and was enlarged due to concentric left ventricular hypertrophy (LVH). The left ventricular wall measured 1.8 cm thick (average 1.3 cm). LVH is commonly associated with longstanding hypertension. Toxicology identified valsartan in urine and cavity blood.