Accident Details
On August 28, 2010, at approximately 0755 eastern daylight time, an Air Tractor AT-402B (registration N4172U) operated by Frost Flying Inc. was substantially damaged when it impacted terrain during an aborted takeoff from Pompano Beach Airpark (PMP) in 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 positioning flight to Borinquen, Puerto Rico, conducted under 14 CFR Part 91.
Aircraft Information
According to FAA records, the airplane had been issued a special airworthiness certificate in the restricted category for "Agriculture and Pest Control/Forrest" on May 21, 2010. It was equipped with a Pratt & Whitney Canada PT6A-15AG engine producing 680 horsepower. The aircraft had accumulated approximately 10 hours since new at the time of the accident and was being flown to Puerto Rico en route to its owner in Brazil.
Takeoff and Accident Sequence
The pilot attempted takeoff from runway 10, a 3,502-foot-long, 150-foot-wide asphalt runway, using 10 degrees of flaps. The airplane accelerated to takeoff speed and lifted off without incident but would not climb out of ground effect and settled back onto the runway. The pilot continued the takeoff attempt and rotated again as the aircraft approached the end of the runway. It climbed to about 10 to 15 feet above the ground before settling again onto a grass area beyond the runway. The pilot then aborted the takeoff, but the airplane traveled through a chain link fence and struck trees, sustaining substantial damage to both wings and the fuselage before coming to rest in a parking lot. The distance from the end of the runway to the fence was about 600 feet.
Pilot and Weather
The pilot, age 68, was a former airline pilot with 34,546 total flight hours, including 613 hours in the same make and model. He had flown 126 hours in the preceding 90 days and 45 hours in the preceding 30 days. His most recent first-class medical certificate was issued on January 22, 2010. Weather at the time included winds from 080 degrees at 6 knots and a temperature of 84°F.
Weight and Performance
The airplane was loaded with additional fuel for the delivery flight, with an accident weight of 8,384 pounds. The normal maximum takeoff weight was 7,000 pounds, but for agricultural purposes the maximum gross weight was 9,170 pounds. The Air Tractor AT-402B flight manual did not provide a takeoff distance chart for weights above 7,000 pounds. According to an Air Tractor representative, under the reported conditions, the estimated ground roll was 3,373 feet and the air distance to clear a 50-foot obstacle was an additional 3,195 feet. The manual recommended using 10-degree flaps for takeoffs with full-hopper loads and short fields.
Examination
The pilot reported observing white smoke from the engine exhaust when the airplane first lifted off and attempted to climb. The airplane rolled about 100 to 150 feet on grass before aborted. The aircraft was equipped with a smoke system, but the source of the smoke could not be determined. Initial examinations of the airframe and engine by Air Tractor and Pratt & Whitney Canada representatives under FAA supervision did not reveal any preimpact malfunctions. Additional engine testing at Pratt & Whitney Canada using a slave power section demonstrated normal gas generator operation. The propeller examined at Hartzell Propeller Inc. showed no discrepancies that would preclude normal operation, and damage was consistent with rotation, though specific power output could not be determined.