20240614006952A

The company owning and operating the two mishap aircraft was hired to spray two adjacent fields. The two square fields form a rectangle aligned north-south and east-west. The east-west axis is the long side of the rectangle. Both fields have a pivot irrigation system resulting in two circular cultivated areas in the center with small wedge-shaped areas at each corner of the square field. There are two double corners in the middle of the rectangle where the two fields touch. The corners are often not planted requiring weed control with chemicals differing from those used on the cultivated portion.

The morning of the mishap, the chief supervisor assigned each mishap pilot their task for that morning's flights. The chief supervisor thought he was assigning the two pilots fields in different locations. In reality, the pilots were mistakenly assigned the same two adjacent fields. This mistake is an operational factor attributed to other than the pilots as this, unintentionally and unknowingly to all involved, put both aircraft in the same piece of sky at the same time. The pilots did not recognize the situation until mishap pilot b (mp-b) contacted mishap pilot a (mp-a) inbound to the assigned field.

Mp-a was tasked to spray the corners of his assigned two fields. Mp-b was assigned to spray the cultivated circles of his two fields. The aircraft were loaded with different chemicals, each appropriate for their assigned tasks.

When mp-a departed the company’s runway, he thought he was to be the only aircraft working his assigned fields. After an uneventful flight to the fields, mp-a began to spray the two eastern corners using a north-south flow. As mp-a was finishing the chemical application on the two eastern corners, mp-b contacted mp-a and informed mp-a he was inbound and they would both be working the same fields.

Mp-a’s aircraft radio push-to-talk switch was inoperative. All communication between the two pilots was conducted via the bluetooth connections of their smart phones to their headsets. Mp-b held to the northeast to coordinate with mp-a.

It was decided mp-a would work the corners in an east-west flow while mp-b worked the cultivated portion in a north-south flow. At the end of each pass, mp-b was to stay low and mp-a was to climb up to provide altitude deconfliction between the two aircraft during repositioning.

Mp-a positioned his aircraft to the west of the fields setting up for his first west to east pass over the remaining southern corners of the field. Mp-b positioned his aircraft north of the middle of the eastern field to begin his first pass.

As mp-a was completing his first pass over the southern double corner, he saw mp-b’s aircraft at his ten o’clock position and began a pull up to provide the agreed upon deconfliction. Early in his pitch up, mp-a saw that mp-b was also pitching up.

Mp-a saw the conflict developing and banked hard to the right while continuing to climb. Mp-a lost sight of mp-b’s aircraft as mp-a continued to turn away in an attempt to avoid colliding with mp-b’s aircraft.

The two aircraft collided shortly after mp-a began his turn and crashed, destroying both aircraft. Mp-a sustained a serious injury. Mp-b died as a result of the crash.