Date: 201201
Local time of day: 1801-2400
Location: PHL.Airport, PA
Aircraft: Regional Jet CL65; Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Takeoff / Launch
Second aircraft: B737 Undifferentiated or Other Model
Reporter organization: Government
Reporter function: Traffic Management
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Other / Unknown
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Air Traffic Control
Result: General None Reported / Taken
Contributing factors: Procedure
Primary problem: Procedure

Narrative: PHL was in a west flow; Runway 27R/35 in use; OJT being conducted on Local Control East. Steady arrivals to both 27R and 35; however departures on 27L were light. Ground Control East assigned a CRJ Runway 35 Intersection Kilo for departure. When the CPC in training working Local Control East gave the CRJ line up and wait instructions at Intersection K; traffic for that runway was about 2-3 miles out and traffic landing Runway 27R (a B737) was 1 to 1.5 miles from touchdown. When traffic cleared Runway 35 in front of the CRJ; the CPC-IT cleared the CRJ for take off as the B737 was just touching down. As the CRJ powered up for departure roll; the landing B737 received the full force of the jet blast. I'm not aware of any wake turbulence/jet blast warning to the landing aircraft. This event has occurred numerous times before; both at the intersection of Runway 27R/35 and also with Runway 8 departures and 17/35 arriving aircraft. It has generated safety reports and courtesy e-mails from pilots who were concerned about the situation; including one where I believe the pilot stated he nearly lost control of his aircraft after being hit with jet blast on landing roll. In the past; the response from both the facility and airport management has been for the controllers to be more aware of the situation and to try to avoid the scenario. The discussion in the Tower after today's event included statements from controllers that this was a legal operation with nothing in the 7110.65 or our local SOP that prohibits the operation. Restrict Runway 35 Intersection Kilo departures to propeller driven aircraft. This will have little effect on delays as few jets are able to use Runway 35 for departure. On an east flow; with a secondary runway in use; restrict Runway 8 departures to propeller driven aircraft. This will affect our departure rate on the east flow; however I believe we will eliminate a serious safety risk from our operation. If we just tell controllers to avoid the situation without giving specific instructions/rules to follow; this situation will repeat itself over and over as different controllers have different opinions of what is enough space for a safe operation.




Synopsis: PHL Controller described a potential jet blast event when traffic departing Runway 35 from Taxiway K initiated take off power just as an arrival was landing Runway 27R; the reporter noting the operation was legal but safety concerns were present and those concerns have been raised by the users.