Incident Overview
A United States Air Force KC-135 tanker aircraft and an AA-1 light aircraft collided in midair approximately 5 miles south of Luke Air Force Base at an altitude of 2,500 feet MSL. The KC-135 was operating under an instrument flight rules (IFR) flight plan and was executing a TACAN approach to Runway 3L at Luke AFB. The AA-1 had departed from Sky Harbor Airport and had been released by Phoenix Terminal Radar Service Area (TRSA). The AA-1 was proceeding in a westerly direction within airspace designated as a special traffic area, where aircraft were required to be at or below 2,000 feet MSL.
Witness Account
A pilot of another aircraft, who was trailing the AA-1, provided a statement regarding the events leading up to the collision. The trailing pilot reported encountering a low broken cloud cover, necessitating a descent to approximately 2,000 feet MSL to maintain a 500-foot separation below the cloud bases. According to this pilot, the pilot of the AA-1 did not descend and instead appeared to be skimming along in and out of the cloud bases. The trailing pilot then noticed the KC-135 descending through the cloud deck, followed immediately by the collision.
Pertinent Details
The AA-1 pilot's logbook indicated that this was his first trip to the Phoenix area. Luke AFB was depicted on the north side of the sectional chart only. Additionally, VOR Airway #16 was split along an east-west line, with the northern and southern halves displayed on opposite sides of the chart.
Investigation Findings
The collision occurred at an altitude of 2,500 feet MSL, which is above the 2,000-foot MSL altitude restriction for the special traffic area. The source does not provide a probable cause for the accident.