20140521007489A

Times, headings, measurements & altitudes are approximate. Aircraft N702CB, ayres S-2R, registered to & operated by clear skies aviation; took off from the sher-wood airport (kpwd), plentywood, Montana, may 21, 2014 @ 1315 MDT & went south 15 miles towards Medicine Lake, Montana to finish spraying a field that had been started earlier. Visual meteorological conditions existed at the time. No flight plan had been filed. Accident site is 2,000? Asl. The aircraft impact was high angle & medium energy. The aircraft was substantially damaged, the insurance company declared the aircraft totaled. The aircraft impacted the ground with substantial damage to the tail/empennage, left wing, left gear, engine & propeller, in order of severity.

During the post-accident interview, pilot stated he had just completed his last pass going south, at this time he had used all his spray, roundup? & was pulling up to turn back toward the airport to the north. He was at 140 mph when he started to enter into a shallow climbing turn. He stated the next events were not clear to him. The aircraft started to descend & the pilot could not stop descent with elevator input. After the aircraft contacted the ground, he released the control stick & braced for impact, pulling his feet off the rudder pedals & gripping the seat pan bottom with his hands. He estimated time of impact to be 1 - 2 seconds later based on the distance traveled from the point of impact. The engine was still ?making noise? After the crash, & he pulled the emergency fuel shut off at that time, although he was not sure if it was running or just spooling down. He exited the aircraft through the left door. The pilot had a bruise on his inner thigh from the control stick hitting him. He thought he had 40 gallons of fuel in the aircraft at this time.

All prop blades were bent, 1 forward at a 20 degree angle about 70% of the blade, the other 3 backwards. Leading edge rock impact bending gives evidence to blades contacting the ground at a very flat pitch. Marks on the inside of the propeller hub from pitch links indicate the prop blade angle was driven past the reverse position. The inside of the spinner had marks from all 4 counterweights over-travelling as well. All 4 pitch links were intact & not bent or damaged. There is dirt impacted & stuck to the forward facing (grey) sides of the blades. There are scrub marks in the direction of rotation on the ends of the prop blades.

Flight & engine control continuity verified, & flaps were in the up position.

Both airframe fuel filters were clean, with a small amount of particulate in the drainable filter bowl. There was evidence of rust, level 1, in the drainable filter bowl, but it appeared to be old, not fresh. There was no evidence of water in either fuel filter housing. No evidence of any sludge or other biological contaminants were noted.

The left wing outer 25% was broken off, & was further partially severed & bent up about half way out, with the left aileron attached to the rear spar torn off as an assembly. The right wing was mostly undamaged, but the aileron was damaged from contact with the spray boom hanger when it was in the down position & the spray boom hanger was bent up.

Cockpit area did not sustain any crushing or folding. Control stick switches were damaged from contact with the aft end of the hopper on the sight glass when it traveled past the stops. The site glass had cracked in a spiderweb from this impact, but the glass was still intact. The seat, seat belts & shoulder harnesses were all intact.

When the aircraft was recovered, there was 2 qts of fluid left in the hopper, 10 ? 12 gallons of fuel in the rt undamaged fuel tank, & 2 ? 3 gal from the lt ruptured tank. All instrument gage faces were intact.

The aft fuselage deformed from impact starting just aft of the cockpit, bending up & to the right first, with the empennage then bending back to the left aft of this at the stab attach.