NTSB Factual Report

HISTORY OF FLIGHT

On September 12, 1995, at 0825 hours Pacific daylight time, a Cessna U206G, N6355U, collided with flat terrain while on an aerial application flight near Dos Palos, California. The aircraft was owned by Inland Crop Dusters, Inc., and was operated as a public-use aircraft under an exclusive use contract with the U. S. Department of Agriculture (USDA) when the accident occurred. The aircraft was destroyed and the commercial pilot and the pilot-rated passenger sustained fatal injuries. The flight originated in Shafter, California, at 0608 on the day of the accident. Visual meteorological conditions prevailed at the time and no flight plan was filed.

The contract between the aircraft owner and the USDA required the owner to supply aircraft and crews for an insect eradication program. The flight involved the aerial dispensing of sterile Bullworm moths over specified agricultural fields. The pilot was familiarizing the pilot-rated passenger, who was being considered for employment on the contract, with the aerial tasks to be performed.

The sole witness to the crash was located about 1.5 miles from the accident site. He reported first observing the aircraft spinning to the right in a nose-down attitude from an altitude he estimated between 500 to 600 feet agl. He stated that after the aircraft completed two rotations to the right it stopped spinning, but continued in the nose-down attitude to ground impact.

The aircraft owner reported that standing operating procedures directed the pilots to disperse the moths while at 500 feet agl and 110 mph. When flying between dispersing locations, the pilots are instructed to use a manifold pressure of 23 inches and propeller rpm of 2,300, which results in an airspeed of 120 mph. The owner said he personally verified that the pilot adhered to these procedures during previous flights when he flew with the pilot. According to the USDA representative, the accident occurred while the aircraft was en route between dispersing locations. FAA facility records disclosed no record of any communication or other services provided to the aircraft on the day of the accident. Search of the recorded radar data for the location, time, and date of the accident revealed no targets which could be associated with the aircraft.

PERSONNEL

Review of FAA Airman Record files, company records, and personal logs/documents revealed that both the pilot and pilot-rated passenger held commercial pilot and second-class medical certificates. Both pilots had recent experience in the Cessna U206 series aircraft.

In an interview, the aircraft owner said he had known the pilot for several years and during that time they had flown together on several occasions. The owner reported that the pilot was a professional who always adhered to safe operating practices.

The owner reported that he met the pilot-rated passenger prior to the day of the accident and was continuing to evaluate the possibility of hiring him as a pilot. He said that both the pilot and the prospective pilot had previously flown together on three or four dispensing operations. The pilot had not made any negative report to the owner about the passengers attitude or technical performance. The owner stated that his impression of the prospective pilot was positive and that his demeanor seemed compatible to that of the pilot.

AIRCRAFT INFORMATION

The aircraft was operated under a restricted category airworthiness certificate, which was issued due to the installation of the live moth dispensing device. The device was installed in place of the rear aircraft seats on the floor behind the pilot and co-pilot seats.

The aircraft owner reported that refuelers topped off both fuel tanks prior to departure. Based on the reported onboard fuel quantity and the estimated duration of the flight to the accident site, investigators estimated that sufficient fuel was available to complete the flight.

Aircraft gross weight and center of gravity was computed using the standard manufacturer's weight and balance form for the aircraft. It was established that the aircraft was within the prescribed limits.

WRECKAGE AND IMPACT INFORMATION

The aircraft impacted on an unobstructed, flat row agricultural field, at an elevation of 120 feet msl. The field was wet and soft. The fuel tanks were crushed and ruptured and the odor of fuel was persistent when Safety Board investigators arrived. The Fresno County Fire Department reported that there was no residual fuel in either tank when they arrived at 1000 hours. Both fuel tanks exhibited hydraulic deformation.

The nose of the aircraft was found buried in the ground at the initial impact point, and the longitudinal axis of the engine was observed in a near vertical nose-down attitude. The wreckage distribution was concentrated at the initial impact point with the longitudinal axis of the aircraft oriented on a magnetic bearing of 360 degrees. The wreckage was disturbed by emergency rescue personnel during extrication of the occupants.

All aircraft components were accounted for at the accident site. Control continuity was established and no evidence of control surface binding or chafing was observed. The elevator trim tab actuator was extended 1.85 inches, which the manufacturer's technical representative stated corresponds to a 15-degree tab up setting.

The cabin area was collapsed with the following control positions noted: mixture, propeller, and throttle controls full forward; cowl flaps open; alternate air in the automatic position; cabin heater off; and fuel selector valve positioned to the left main tank. The aircraft was equipped with functioning dual controls. Both seat belts and shoulder harnesses were installed and were cut by responding fire department units during occupant extrication efforts. The seat supports for both front seats were collapsed.

The propeller hub with two blades attached were found buried in the ground at the point of impact. The third blade was found a short distance away.

MEDICAL AND PATHOLOGICAL INFORMATION

The responding deputy coroner reported that when he arrived he found the pilot on the ground outside the right side of the aircraft, while the pilot-rated passenger was located on the left side. Autopsies were conducted by the Fresno County Coroner with samples retained for toxicological testing. Negative results for alcohol and all screened drug substances were reported for both occupants.

The coroner reported that the pilot sustained a fracture dislocation of the right thumb. The pilot-rated passenger sustained a fracture dislocation of the right thumb metacarpal-carpal joint and the right wrist joint.

TESTS AND RESEARCH

The engine was removed and shipped in a sealed container to Teledyne Continental Motors in Mobile, Alabama, for detailed examination under the supervision of an FAA inspector. The manufacturer's analytical inspection report is appended to this report and the photographs referred to therein are on file with the manufacturer. No discrepancies were identified during the examination.

ADDITIONAL INFORMATION

The aircraft wreckage was released to a representative of the USDA on December 4, 1995.

NTSB Probable Cause

the pilot-in-command's failure to assure that adequate airspeed was maintained.