FTW83AA024

A PA-31, N100FD, was being vectored by dfw approach control (apch ctl) for a landing on rwy 13L at dallas-love fld. The plt's last received & acknowledged instructions were to descend & maintain 2000' & turn left to 190 deg. Simultaneously,a Cessna 337, N72430, departed rwy 15 at addison arpt, under tower control, & was to make a rgt climbing turn of aprx 180 deg. Two min after takeoff, the plt asked & got approval for freq chng. 24 sec later, he contacted apch ctl stating he had just departed addison & was climbing to 2500' on a 300 deg hdg. The controller misunderstood the plt's departure point & instructed him to change to freq 120.5. The 2 acft immediately collided. A 2000' ceiling was reported, 2 witnesses stated they could see more blue sky than clds. A witness aprx 8 mi away saw a fireball in the clds. Investiga-tion revealed the controller, vectoring N100FD, prematurely cleared the acft to an alt which was below the ceiling of the addison arpt traffic area & prior to reaching the airspace delegated for that purpose by an ATC letter of agreement.

A PA-31, N100FD, was being vectored by dfw approach control (apch ctl) for a landing on rwy 13L at dallas-love fld. The plt's last received & acknowledged instructions were to descend & maintain 2000' & turn left to 190 deg. Simultaneously,a Cessna 337, N72430, departed rwy 15 at addison arpt, under tower control, & was to make a rgt climbing turn of approx 180 deg. Two min after takeoff, the plt asked & got approval for freq chng. 24 sec later, he contacted apch ctl stating he had just departed addison & was climbing to 2500' on a 300 deg hdg. The controller misunderstood the plt's departure point & instructed him to change to freq 120.5. The 2 acft immediately collided. A 2000' ceiling was reported, 2 witnesses stated they could see more blue sky than clds. A witness aprx 8 mi away saw a fireball in the clds. Investiga-tion revealed the controller, vectoring N100FD, prematurely cleared the acft to an alt which was below the ceiling of the addison arpt traffic area & prior to reaching the airspace delegated for that purpose by an ATC letter of agreement.