Incident Overview
On the day of the accident, a Piper PA-31 (registration N100FD) was being vectored by Dallas-Fort Worth (DFW) approach control for landing on runway 13L at Dallas-Love Field. The last instructions acknowledged by the pilot of N100FD were to descend and maintain 2,000 feet and turn left to a heading of 190°. Simultaneously, a Cessna 337 (registration N72430) had departed from runway 15 at Addison Airport, operating under tower control. The Cessna was instructed to make a right climbing turn of approximately 180°.
Communication Sequence
Two minutes after takeoff, the pilot of N72430 requested and received approval for a frequency change. 24 seconds later, the pilot contacted approach control, stating that he had just departed Addison and was climbing to 2,500 feet on a heading of 300°. The controller misunderstood the departure point and instructed the pilot to change to frequency 120.5. The two aircraft immediately collided.
Weather and Witness Accounts
A 2,000-foot ceiling was reported at the time. Two witnesses stated that they could see more blue sky than clouds. A witness approximately eight miles away observed a fireball in the clouds.
Investigation Findings
The investigation revealed that the controller vectoring N100FD prematurely cleared the aircraft to an altitude that was below the ceiling of the Addison Airport traffic area, and prior to reaching the airspace delegated for that purpose by an ATC letter of agreement.
The official probable cause findings, as stated in the investigation, were: Occurrence #1 – midair collision; Phase of operation: approach – IAF to FAF/outer marker (IFR); Findings: (1) procedures/directives – not followed by ATC personnel (dep/apch); (2) VFR procedures – improper by pilot of other aircraft; (3) weather condition – clouds.