Date: 201210
Local time of day: 1801-2400
Location: PCT.TRACON, VA
Aircraft: B737-300
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Final Approach
Airspace: Class E PCT
ATC / advisory: TRACON PCT
Second aircraft: Skyhawk 172/Cutlass 172
Reporter organization: Government
Reporter function: Approach; Departure
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Other / Unknown
Second reporter function: Departure; Approach
Anomaly: ATC Issue All Types; Conflict Airborne Conflict
Detector: Person Air Traffic Control
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Procedure
Primary problem: Procedure

Narrative: I was working BWIFN/FS combined position in a 15L/15R operation running visual approaches. We are required to run 5 mile final interval for Runway 15R due to runway closures for 10/28. We are now also required to have our parallel traffic for Runway 15L to be no more than a 30 degree turn to final to reduce the chance of a belly up situation. This is work intensive for a normal flow VFR day only having to run a 3 mile final but with the additional restrictions for the airport it just adds more complexity to the situation. The Galaxy jet was issued a 200 heading and he reported the airport in sight; at the time there was no conflict with the B737 aircraft. He proceeded to the airport and I switched the aircraft. The B737 was given a 130 degrees turn to join they reported the field and were established on the localizer and cleared for the visual but since the Galaxy jet had been issued a 200 heading they 'lost separation' according to the TARP. The 30 degree vector to establish a straight in situation should not affect airports with parallels with more than 4;300 FT or more between center lines. There are two issues I see that can and will happen. First the pilot will report the field but we'll deny the approach clearance so we can give them the intercept turn; put them on a base turn and then get busy with other aircraft or coordination. They'll blow right through the final causing either an accident or real separation errors which could cause devastating consequences and what we call the snow ball effect. Second we give them the turn and a visual approach clearance and then they turn to whatever angle they want for the approach. Once the visual approach clearance is given all our instructions have now been removed and it is in their right to fly the approach visually as they see fit. So how is this ensuring anything? It increasing our work load and increases cost for aircraft with fuel; operation cost etc.


Second narrative: I was working our final position combined. Running visual approaches to 15L/15R I gave headings toward the airport for each aircraft that would alleviate the belly up situation when both aircraft had the field in sight I cleared them for the approach. The TARP indicated that they were outside the 30 degree intercept and indicated I had a 'loss of separation'. I feel the 30 degree intercept adds unnecessary work loads for controllers and operational cost for airlines for the excessive vectors for visual approaches. It should be reviewed for airports that have parallels that have more then 4;300 FT between runways. There was no unsafe situation for these two aircraft's approaches.


Synopsis: PCT Controller voiced concern regarding current visual approach 'turn on' restrictions as applied to visual approach procedures. The reporter noted the procedure is costly and introduces several safety concerns.