Accident Details
On October 5, 2012, at approximately 1407 mountain standard time, a midair collision occurred between two Piper aircraft approximately 12 miles south of Chandler, Arizona. The aircraft were a Piper PA-28-161 Warrior, registration N8115Q, and a Piper PA-28R-201 Arrow, registration N4184M. Both airplanes were being operated under 14 Code of Federal Regulations Part 91 as local instructional flights.
The Warrior was owned and operated by Chandler Air Service Inc., while the Arrow was owned by Aircraft Guaranty Corp. and operated by CAE Oxford Aviation Academy. Each aircraft carried a certified flight instructor (CFI) and a student pilot. No injuries were reported from either airplane.
The Warrior departed Chandler Municipal Airport (CHD) at about 1335, and the Arrow departed Falcon Field Airport (FFZ) at about 1230. Visual meteorological conditions prevailed, and no flight plan was filed for either flight.
Pilot Accounts
According to the flight instructor of the Arrow, he and the student pilot had just completed a non-directional beacon (NDB) interception exercise with the student wearing a view-limiting device. Shortly after, the instructor noticed a very close, fast-moving blurred object approaching from almost directly ahead. The object seemed to be in a left turn and was lower than his airplane. After the impact, the Arrow yawed left and dropped a wing; the instructor took control and stabilized the airplane.
The flight instructor of the Warrior reported that he had given his student pilot a simulated instrument clearance, and the student was wearing a view-limiting device. He then saw an airplane directly ahead and slightly higher in altitude. The airplane appeared to be in a slight left turn. He took the controls and made an abrupt nose-down left turn prior to impacting the other airplane.
Damage
After the collision, the Warrior landed at Gila River Memorial Airport (34AZ) in Chandler, Arizona, with substantial damage to the right wing. The Arrow landed on the Volkswagen Group of America test track in Maricopa, Arizona, with substantial damage to its left wing and horizontal stabilator.
The Warrior's right wing separated about 3.5 feet from the wing tip, along with an outboard section of the right aileron. The aileron balance weight was not found during the examination.
The Arrow's left wing was damaged outboard and adjacent to the wing fuel tank. Approximately 14 inches of the leading edge structure was crushed to the main spar, and a portion of the Warrior's wing remained within the structure. The Warrior's right wing tip protruded from the top and bottom of the Arrow's wing. The leading edge of the left horizontal stabilizer sustained impact damage.
Radar Data
Recorded radar data from the FAA's Phoenix Terminal Radar Approach Control (TRACON) ARTS IIIA radar system was obtained and reviewed. Neither airplane had requested flight following or received any radar guidance during the accident flights. Between 1405:39 and 1406:20, two radar beacon targets proceeded on a southwesterly track, one ahead of the other, about 6 miles northeast of the University of Arizona Maricopa Ag Center Airport (3AZ2). The targets were spaced about 2 miles apart, and both indicated Mode C reported altitudes of 4,000 feet mean sea level. At 1406:25, the rear target (the Arrow) changed to a westerly heading, and 40 seconds later the forward target (the Warrior) began a right turn into the path of the rear target. At 1407:06, both targets merged and then separated. One target (the Warrior) then departed to the northeast, changed heading to the north, and disappeared near Gila River Memorial Airport. The other target (the Arrow) departed to the southwest and disappeared from radar 2 miles east of 3AZ2.
Collision Avoidance System
The Arrow was equipped with a Portable Collision Avoidance System (PCAS) capable of detecting and displaying range, bearing, and altitude information of transponder-equipped aircraft. According to the flight instructor of the Arrow, the unit had alerted him twice during the flight but did not alert prior to the collision. The unit was sent to the National Transportation Safety Board Materials Laboratory for examination. Its alert settings were set to a range of 3 nautical miles and a vertical range of 1,500 feet. The external speaker and headset interfaced audio tested properly, and no anomalies were noted with the unit. An examination report is contained in the public docket for this accident.
Neither pilot reported any preaccident mechanical malfunctions or failures with their aircraft that would have precluded normal operation.