SEA07LA242

During the takeoff roll on the 2,400 foot long asphalt airstrip, the 7,650-hour pilot noticed the airplane was very sluggish about 60% of the way down the runway, and not being able to stop he elected to add full power. The aircraft subsequently became airborne in ground effect; however, it settled and impacted terrain on the other side of a crowned road past the end of the runway. After impacting the ground the airplane veered to the right 180 degrees before coming to rest upright. The pilot said the accident could have been prevented if he had reduced his load and had stopped flying when it became too hot. The density altitude was calculated at 3,672 feet based on an outside air temperature of 41 degrees Celsius, a dew point of 12 degrees Celsius, and an altimeter setting of 29.65 inches of Mercury.

On August 28, 2007, approximately 2000 Pacific daylight time, an Air Tractor AT-502B, N6003G, operated by Cyr Aviation of Blythe, California, sustained substantial damage after impacting terrain following takeoff from a private airstrip near Blythe. The airline transport pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed for the aerial application flight, which was being conducted in accordance with 14 CFR Part 137, and a flight plan was not filed. The local flight was originating at the time of the accident.

In an interview with the NTSB investigator-in-charge (IIC), and according to the Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1), the 7,650-hour pilot reported that on the takeoff roll from the 2,400-foot asphalt airstrip the airplane felt "excessively sluggish" at the point where it was too late to stop. The pilot stated that he applied full power, which overtemped the engine when approximately 60% of the runway was used, and then began dumping his load when he had used about 70% to 75% of the runway. The pilot further stated that the airplane then ran off the end of the runway "barely in ground effect," with the main landing gear tires clearing a crowned road at the end of the runway. The pilot reported that the airplane settled out of ground effect before impacting terrain on the other side of the road and yawed 180 degrees to the right before coming to a stop in an upright position. There was no post-accident fire.

The pilot, a certified FAA airframe and powerplant mechanic, reported that all three propeller blades were bent, the right wing tip was damaged, the left wing was destroyed and the fuselage aft of the cockpit was broken in half. The pilot further reported that the [main] landing gear was bent and the tail wheel was separated.

The pilot reported that prior to taking off he had reduced his chemical load to be 325 gallons, and that the temperature was 110 degrees Fahrenheit. The pilot stated that he had made thousands of takeoffs under similar conditions before with no problem, and that he just didn't know what happened. Under the Recommendation (How could this accident/incident have been prevented) section of NTSB Form 6120.1, the pilot stated, "Reduce load size greatly" and "Cease flying during hot weather."

Based on the outside air temperature of 41 degrees Celsius, a dew point of 12 degrees Celsius, and an altimeter setting of 29.65 inches of Mercury, the IIC determined the density altitude was 3,672 feet. The field elevation at the private airstrip is listed as 263 feet.