LAX98GA110

In furtherance of the U.S. Department of Agriculture's Animal Plant Health Inspection Service (APHIS) Wildlife Services aviation program, the rear seat instructor-gunner and the front seat trainee-pilot commenced aerial hunting operations which required the trainee-pilot to maneuver at slow airspeed and low altitude while the instructor-gunner shot coyotes. The instructor was also required to be observant of the recently hired trainee's flying skill and provide any needed instruction. On previous flights, the instructor had observed the trainee experiencing difficulty maintaining altitude during turns. He also opined that the trainee was not strong enough to fully extend the wing flaps. The trainee used two seat cushions behind her back to reposition her closer to the flight controls (and the instrument panel). The instructor did not report his observations to management. During the accident flight following a coyote shoot, the trainee entered a low altitude, slow airspeed, medium bank turn to reverse course. During the turn, the instructor's attention was diverted to search the cabin floor for an ejected live shotgun shell. The instructor looked outside the airplane just as the left wing impacted the level terrain in a nose low attitude. The USDA operated the public-use airplane and directed the instructor to have it maintained by contract mechanics in accordance with FAA regulations. Contrary to the airplane manufacturer's FAA type certificate, the USDA had erroneously connected the front seat shoulder harness, with its associated inertial reel, to the back of the front seat instead of using the prescribed factory mandated location at an overhead airframe hardpoint. Additionally, the shoulder harness webbing was routed beneath seatback material. An engineering analysis revealed that due to the anchoring of the harness to the seat structure rather than the prescribed airframe hardpoint, and the nose low ground impact trajectory, the inertial crash loads to the seat increased thus exceeding its designed strength. The improper harness attachment combined with the compressive fuselage buckling resulted in the seat yielding in a forward bending direction. The trainee's head impacted the instrument panel resulting in fatal injuries. The airplane had undergone four 100-hour and an annual inspection with the harness incorrectly attached.

History of flight

On March 11, 1998, at 1009 hours Pacific standard time, a Christen A-1, N9615G, operated by the United States Department of Agriculture (USDA) as a public-use aircraft, collided with terrain approximately 8 statute miles north of Lebec, California. At the time of the accident, the front seat pilot was maneuvering the airplane at a low altitude in furtherance of the USDA's Animal Plant Health Inspection Service (APHIS) Wildlife Services program. Visual meteorological conditions prevailed, and a company flight plan was filed. The airplane was destroyed, and the commercial pilot in the front seat (a trainee in the program) was fatally injured. The rear seat crewmember, who also possessed a commercial pilot certificate, was performing aerial gunnery and instructional duties. He was seriously injured. The local area flight originated from an open field about 0930. The field was located about 5 miles from the crash site, northwest of Interstate Highway 5 and the Pump Plant Road.

The USDA management reported that the mission of the APHIS program is to curtail damage to agricultural products caused by wildlife. To effectively accomplish the program's objectives, the Wildlife Services aviation program requires its pilots to fly in close proximity to the ground while maneuvering at slow airspeeds. The accident occurred during an authorized aerial hunting flight operation over a designated work site on private property. The flight crew consisted of a trainee-pilot and an instructor-gunner.

An USDA employee-witness, who was working as a ground crewmember in the coyote hunting operation, and the instructor-gunner reported the sequence of events leading to the accident. In summary, the ground-based witness, who was approximately 1/3-mile from the accident site, reported seeing the airplane flying at its customary low altitude. About 30 seconds prior to the crash the witness informed the airplane's crew via radio that he intended to reposition himself closer to the area where the airplane was flying. The instructor-gunner acknowledged his radio transmission and did not indicate any difficulty with the airplane.

The witness further reported observing the airplane commence a gradual left, course-reversal turn, and nothing unusual was noted. After about 8 seconds the airplane commenced another left turn. The left wing lowered and a 30- to 45-degree angle of bank was established. Within a second after initiating the left turn, the airplane appeared to be flying more slowly and at a lower altitude than normal, and this alarmed the witness. As the turn progressed, the left bank angle slightly increased and the airplane impacted the ground.

The instructor-gunner made several verbal and written statements regarding the sequence of events leading to the crash. In pertinent part, he reported the following:

During the accident flight his primary function was to kill coyotes. Secondarily, he was supposed to be observant of the manner in which the front seat trainee-pilot was handling the airplane's controls and provide any needed guidance.

The instructor verbally reported that during an earlier low-level turn, the trainee-pilot had allowed the airplane's nose to abruptly lower (as the angle of attack decreased) and the airplane dove toward the ground. The instructor stated that he had informed the trainee that her handling of the airplane was improper, and he provided guidance to resolve the problem.

The instructor further reported that a few minutes prior to the crash he shot a coyote. After the shoot, the pilot began reversing course to overfly the general area.

The pilot climbed approximately 100 feet above ground level (agl), and then, while looking for additional animals, descended to between 50 and 60 feet agl. Thereafter, the pilot descended to about 20 to 25 feet agl. The instructor ejected a live shell from the shotgun. The shell landed on the airplane's floor rather than in the shell pouch on the rear of the pilot's seat. (The USDA reported that its policy requires that before a firearm is returned inside the airplane, the firearm's breach must be cleared of any live ammunition. This process requires the gunner to briefly redirect his attention from outside to inside the airplane.)

The instructor indicated that he redirected his attention from outside the airplane toward the airplane's floor to look for the shell. During this time, the instructor reported that he felt the airplane turn left, the engine power remained around 2,000 or 2,200 rpm, and the stall warning horn activated. The bank angle was more than 30 or 40 degrees, perhaps as much as 65 degrees. The instructor looked up from the floor as the airplane's nose lowered. He attempted to grab his control stick; however, the airplane crashed.

The instructor also reported that the pilot "never let on that anything was wrong or she was having a problem of any kind. The aircraft was running good and we had no problems with the controls to my knowledge."

Personnel information

Front Seat Trainee-Pilot.

The trainee-pilot weighed 104 pounds and was 61 inches tall. She used two personal seat cushions while flying. The cushions were placed behind the pilot's back to move her forward in the seat. The estimated thickness of her cushions was 4 inches. USDA management reported that because the airplane was manufactured with a fixed (nonmovable) seat, some of its pilots utilize supplementary cushions to move them forward enough to reach the rudder pedals.

A review of the pilot's personal flight record logbooks revealed that her total logged flight time was about 4,082 hours. She possessed a certified flight instructor (gold seal) certificate and had given about 1,597 hours of dual flight instruction.

The pilot's first experience flying a Christen A-1 occurred on January 20, 1998. The flight was performed with the instructor-gunner in the accident airplane. The purpose of the flight was to receive initial orientation and familiarization in flight operations associated with aerial hunting. Between January and March, 1998, the pilot logged a total of 66.9 hours in the airplane during training flights on 19 days.

USDA management reported that along with data submitted by the pilot in her employment application, she indicated having 500 hours of low-level type flying experience. The pilot reported that this experience was gained during contract flying for the U.S. Forest Service and search and rescue missions for the Civil Air Patrol.

During the Safety Board's logbook review, no evidence was found of the pilot having any previous low-level flight and maneuvering experience similar to that provided by the USDA in aerial hunting operations.

Rear-Seat Instructor-Gunner.

The instructor-gunner weighs 144 pounds, and he is 71 inches tall. He does not use extra seat cushions while flying.

The instructor-gunner reported that his total flight time was about 6,837 hours, of which about 700 hours were flown in the accident model of airplane. He had flown about 128 hours during the preceding 90-day period.

Flight Training.

According to the instructor-gunner, when he began teaching the pilot, he placed airplane-handling restrictions on her, which were the same as for any pilot he trains. The restrictions were: (1) No turns or passes at less than 60 miles per hour; and (2) No turns using over a 45-degree angle of bank.

The instructor reported that management asked him to provide the new hire with initial indoctrination including flight training appropriate to the USDA's aerial hunting program, and on January 20, 1998, the training commenced. The instructor reported to the Safety Board that the new hire ". . . did a very good job of handling the airplane." But, "she was not strong enough to pull full flaps . . .".

Thereafter, the trainee acquired about 43.3 hours of flight training with