N4172UAir Tractor AT-402B · 2010

On August 28, 2010, about 0755 eastern daylight time, an Air Tractor AT-402B, N4172U, operated by Frost Flying Inc., was substantially damaged when it impacted terrain during an aborted takeoff from Pompano Beach Airpark (PMP), Pompano Beach, Florida. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed and an instrument flight rules flight plan had been filed for the flight destined for Borinquen, Puerto Rico. The positioning flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91.

According to Federal Aviation Administration (FAA) records, the airplane was issued a special airworthiness certificate in the restricted category for the purposes of "Agriculture and Pest Control/Forrest" on May 21, 2010. It was equipped with a Pratt & Whitney Canada PT6A-15AG, 680-horsepower engine.

At the time of the accident, the airplane, which had accumulated about 10 hours since new, was being flown to Puerto Rico en route for delivery to its owner in Brazil.

The pilot reported that he was attempting to takeoff from runway 10, a 3,502-foot-long, 150-foot-wide, asphalt runway, utilizing 10 degrees of flaps. The airplane accelerated to takeoff speed and lifted-off without incident; however, it would not climb out of ground effect and settled back on to the runway. The pilot continued the takeoff attempt and rotated again as the airplane approached the end of the runway. The airplane climbed to about 10 to 15 feet above the ground, before settling again, onto a grass area beyond the runway.

The pilot subsequently aborted the takeoff; however, the airplane traveled through a chain link fence and struck trees. It sustained substantial damage to both wings and the fuselage, before coming to rest in a parking lot. The distance between the end of the runway and the fence was about 600 feet.

According to an FAA inspector, the pilot reported that he observed white smoke coming from the engine exhaust when the airplane first lifted off and attempted to climb. In addition, the airplane rolled about 100 to 150 feet on the grass before the pilot elected to abort the takeoff. The inspector noted that the airplane was equipped with a smoke system; which would have been consistent with the smoke reported by the pilot; however, it could not be determined if the source of the smoke was from the smoke system.

Initial examination of the airframe and engine by representatives from Air Tractor, and Pratt Whitney Canada, under the supervision of a Federal Aviation Administration (FAA) inspector, did not reveal any preimpact malfunctions.

Additional examination of the engine conducted at Pratt & Whitney Canada, Bridgeport, West Virginia, under the supervision of an NTSB Investigator did not reveal any preimpact malfunctions. The power section was damaged consistent with impact forces sustained in the accident. The gas generator section was not damaged and subsequently mated with a "slave" power section for an operational test. The results of the tests demonstrated that the gas generator was capable of normal operation.

Additional examination of the propeller conducted at Hartzell Propeller Inc., Piqua, Ohio, under the supervision of an FAA inspector, did not reveal any discrepancies that would have precluded normal operation. Damage to the propeller was consistent with rotation; however, the specific power output could not be determined.

The pilot, age 68 was a former airline pilot. He reported 34,546 hours of total flight experience, which included 613 hours in the same make and model as the accident airplane. The pilot had accumulated approximately 126 and 45 hours in the same make and model as the accident airplane, during the 90 and 30 days preceding the accident; respectively. His most recent application for an FAA first-class medical certificate was issued on January 22, 2010.

Weather reported at the airport about the time of the accident included, winds from 080 degrees at 6 knots, and a temperature of 84 degrees Fahrenheit.

The airplane was loaded with additional fuel for the delivery flight. According to the pilot, the airplane's weight at the time of the accident was 8,384 pounds. According to the Air Tractor AT-402B type certificate, the normal maximum takeoff weight was 7,000 pounds; however, for agricultural purposes the airplane's maximum gross weight was 9,170 pounds.

The Air Tractor AT-402B airplane flight manual (AFM) did not provide a takeoff distance chart for a gross weight above 7,000 pounds. According to an Air Tractor representative, at the conditions reported at the time of the accident, the airplane's ground roll was estimated to be 3,373 feet, and the air distance to clear a 50-foot obstacle was an additional 3,195 feet. The AFM recommend a flap setting of 10-degrees for takeoffs with full-hopper loads and short fields.