Date: 201407
Local time of day: 1801-2400
Location: PHL.Airport, PA
Light: Night
Aircraft: Medium Large Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class E ZNY
ATC / advisory: TRACON PHL
Second aircraft: Medium Transport; High Wing; 2 Turboprop Eng
Reporter organization: Government
Reporter function: Departure
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Confusion; Distraction; Troubleshooting
Second reporter function: Departure
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Procedure

Narrative: Aircraft X was level climbing to 9;000 FT direct PTW in front of Aircraft Y about 5 miles. Aircraft Y was out of 10;000 FT climbing to 13;000 FT. When Aircraft Y vacated 11;000 FT; I climbed Aircraft X to 11;000 FT. After about a minute or two I noticed that Aircraft Y stopped his climb at 11;400 FT. It appeared that the Aircraft Y stayed at 11;400 for about a minute before starting his climb again. I had already switched Aircraft Y to ZNY Center; so I could not ask him to expedite his climb. When I noticed Aircraft Y leveling off at 11;400; I noticed Aircraft X vacating 10;000 FT. I advised Aircraft X to stop his climb at 10;400 FT. The pilot acknowledged and read back maintain 10;400 FT. It appeared that Aircraft X climbed to 10;600 FT before descending back to 10;400 FT. After calling the ZNY PTW Sector to ask if they knew why Aircraft Y stopped his climb; they replied they didn't know; he checked on and said he was climbing to 13;000 FT. It seemed that the stop climb from Aircraft Y at 11;400 was a direct result of the possible loss of separation.


Second narrative: Aircraft Y departed Runway 27L on the SID (268 heading) climbing to 5;000 FT. I radar identified him. Aircraft Z departed Runway 27L on the SID (268 heading) and I radar identified that aircraft and climbed him to 10;000 FT. I made a couple of other transmissions to other aircraft then came back to Aircraft Y and climbed him to 10;000 FT. After making several other transmissions to other aircraft I noticed that Aircraft Z was gaining speed and catching up to Aircraft Y. I advised Aircraft Z to reduce his speed and issued a turn of 210 degrees to avoid the potential conflict. I had Aircraft X that departed Runway 35 on a 310 degree heading prior to Aircraft Y departing Runway 27L. I wanted to climb Aircraft Y to top Aircraft X going to the same fix; PTW; so I keep him on the SID for a few extra miles. Due to the faster aircraft behind Aircraft Y (Aircraft Z); I should have issued a 290 degree heading to Aircraft Y. This would have prevented the possible loss of separation.


Synopsis: PHL Controller reports of loss of separation between two aircraft under his control. Use of anticipated separation was a factor. He then reports of a second incident involving a third aircraft where speed control and vectoring play a part in another conflict.