Air Traffic Control Fully Certified
Human-Machine Interface
ATC Issue All Types; Conflict Airborne Conflict
Air Traffic Control Issued New Clearance
Aircraft; Human Factors; Procedure
I was working the Asper/Tilly position combined during the arrival push at Dulles. I had numerous aircraft on two different frequencies and created a complex frequency congestion on the position. I had an aircraft depart Dulles on a 270 degree heading. The heavy jet was a southbound departure where the Departure Controller would vector this particular aircraft over the Blues intersection at 12;000 FT. The heavy jet departed Dulles; and I issued an initial instruction for the airplane to climb to 5;000 FT. The Manne Controller was using the radial feed at Dulles in which airplanes descend to 6;000 FT on the two arrivals (Royil/Shnon). I observed the heavy aircraft climbing through 5;100 FT and I an instructed the pilot to maintain 5;000 FT at all times. I did have the opportunity to review the tapes and it clearly states my instruction for the aircraft to climb to 5;000 FT only. The pilot read back 5;000 FT so I expected the aircraft to maintain the assigned altitude. The pilot responded to an RA Conflict and I observed the aircraft climbing to 5;300 FT then back down to 4;800 FT. Right afterward; the aircraft responded to another RA and continued to climb back up to 5;300 FT again. All aircraft were descending to 6;000 FT on the arrival so there was no reason why the TCAS should tell the aircraft to climb because it just escalates the situation. TCAS played the most important part in the situation. TCAS however did not provide the best outcome for the situation; but this could have been an isolated incident. After the heavy jet cleared the traffic; I did climb the aircraft direct to BLUES and switched the aircraft to appropriate sector. During simultaneous approaches at Dulles; climb an aircraft to 4;000 FT if assigned a 270 heading off Runway 30. When departure gets busy; there may be a time when merging traffic calls may not be made due to your attention being diverted somewhere else. In this incident; I had numerous aircraft on frequency with requests. Now you would have at least 2;000 FT of vertical separation to ensure that a TCAS event would not happen. I understand the Tower is protecting for a missed approach; but it ties our hands as a Departure Controller.
While climbing after take off from Runway 30 IAD and being RADAR vectored by Potomac Departure Control; we received a TA followed immediately by a RA. As non-flying pilot I performed a visual scan and located traffic and informed PIC (flying pilot) of aircraft's position. PIC disconnected AFS and followed command bars. Initial response to RA apparently caused a secondary RA which was complied with. ATC issued altitude compliance instructions. I informed ATC of TCAS warnings. ATC requested a telephone call at completion of flight.
PCT Controller described a multiple TCAS RA event involving a departure aircraft assigned 270 heading; the reporter suggesting a lower initial altitude be assigned these aircraft during simultaneous arrival operations.