ATL06LA072

According to the pilot, he was climbing the airplane to 500 feet above ground level and heading to a field 10 miles northeast of the private airstrip. During the climb, the airplane was almost at the intended altitude when the pilot noticed that the internal turbine temperature on the engine was rising and started to lose engine power. The pilot made a forced landing into a soft field and the airplane nosed over. There was a post-impact fire around the engine compartment. Examination of the engine found the power turbine blades fractured with some axial movement noted. Circumferential rub marks were noted on the aft side of the blade roots and disk fir tree slots. The compressor screen was removed and no dents were noted, and all first stage blades were observed intact and rotated freely. No foreign object damage was noted. The engine was split at the "C" flange and some compressor turbine blades were observed fractured at mid-span with trailing edge deformation. No discrepancies were observed in the P3 system. The fuel control unit was impact damaged. The teardown inspection indicated that the engine was operating at the time of impact. Examination did not reveal evidence of uncontainment, case rupture, pre-impact malfunction, or in-flight fire.

On April 28, 2006 at 1530 central daylight time, a Air Tractor AT-502, N1014D, registered to and operated by Morrison Aircraft Corporation, Inc., as a Title 14 CFR Part 137 aerial application flight, made a forced landing and nosed over, shortly after takeoff from a private airstrip in Monroeville, Alabama. Visual meteorological conditions prevailed and no flight plan was filed. The commercial-rated pilot reported no injuries, and the airplane was substantially damaged. A post-crash fire confined to the engine compartment ensued. The flight was originating at the time of the accident.

According to the pilot, he was climbing the airplane to 500 feet above ground level and heading to a field 10 miles northeast of the private airstrip. During climb, the airplane was almost at the intended altitude when the pilot noticed that the internal turbine temperature on the engine was rising and he started to lose engine power. He turned the airplane around and attempted to return to the airstrip that he had departed from, and then "realized he could not make it. He elected to make an emergency landing in the only possible clearing available, which was a pine tree clear cut area." He stated that the "touch down was normal but the wheels dug into the soft ground and the airplane nosed over, coming to rest inverted." The fuel around the engine then ignited into flames. The pilot egressed without injury and notified local authorities.

Examination of the airplane by an FAA Inspector found the propeller and engine gearbox separated from the rest of the engine, and fire damage was localized around the engine compartment. The engine firewall was bent to the left and there was damage to both wings and wing control surfaces. Flight control continuity was established. There was fuel in both wing tanks.

An engine examination was performed on May 22, 2006 by NTSB and Pratt and Whitney personnel. The engine was a PT6A-15AG, Serial Number 14098, and had accumulated 5,181 hours total time and 1,391 hours since its last hot section overhaul. The last recorded maintenance was a 100-hour inspection completed on March 27, 2006. Examination revealed the propeller and power section nose case had separated during impact. The propeller blades had chordwise scratches and were curled aft at varying degrees. The propeller governor linkage was attached. The power turbine blades were fractured with some axial movement noted. Circumferential rub marks were noted on the aft side of the blade roots and disk fir tree slots. The compressor screen was removed and no dents were noted, and all first stage blades were observed intact and rotated freely. No foreign object damage was noted. The engine was split at the "C" flange and some compressor turbine blades were observed fractured at mid-span with trailing edge deformation. No discrepancies were observed in the P3 system. The fuel control unit was impact damaged. According to the Pratt and Whitney representative the power turbine and compressor turbine blade damage was consistent with damage caused while the engine was rotating.