Date: 201403
Local time of day: 0001-0600
Location: PCT.TRACON, VA
Light: Night
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B DCA
ATC / advisory: TRACON PCT
Second aircraft: EMB ERJ 190/195 ER/LR
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Confusion; Workload; Distraction
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic
Contributing factors: Environment - Non Weather Related; Procedure
Primary problem: Procedure

Narrative: In the middle of the evening arrival bank we were given direct orders to change the whole operation due to the A388 requesting departure off Runway 01R.  I was instructed to: discontinue arrivals to my runway (Runway 01R); reassign the rest of my arrivals to Runway 01C and take control of Runway 01C.  The Controller working IADFC & IADFW combined was instructed to: discontinue arrivals to Runway 01C and reassign them all to Runway 01L; release and forward control of Runway 01C to IADFE.  This caused confusion and introduced chaos (risks) into the operation; which in my opinion was not necessary.  I asked the Supervisor; 'Why are we doing this right in the middle of the arrival bank?'  I didn't get a response; instead I got my direct orders.  There are not any standard operating procedures for the operation that we were told to enter; there wasn't any time for a relief briefing or to coordinate with each other (finals); arrival sectors were not made aware of the operation and the Supervisor kept talking to me.  During this; I reassigned Aircraft x from Runway 01R to Runway 01C (within 15-20 flying miles of the airport) and turned base leg.  I didn't realize that I forgot to slow Aircraft X (due to other coordination trying to be accomplished).  When I noticed that Aircraft X was still fast the turn to final was already too late.  I turned to the other final (he was also very busy) to tell him what was going on.  His aircraft (Aircraft Y) was on the opposite base and we were both at the same altitudes (030).  I gave Aircraft X a traffic call on the opposing base leg; he said that he was correcting back to the localizer and had the traffic in sight.  However; separation had already been lost.  I am assuming when I say this: but most pilots would question whether or not they should join the localizer and say something about the speed when that close to the airport.  In this case their workload was also increased by the runway change and didn't have time to question anything because of the situation.  Later on; I was made aware that the Tower told the A388 pilot there would be a delay for Runway 01R; and Runway 30 (the departure runway) was available with no delay.  The pilot of the A388 said that they wanted/needed Runway 01R and would accept the delay.  So why all the unnecessary change in operations? It appears to me that IAD departure traffic has more priority over arrival traffic.  To create unsafe situations in close proximity to the airport (changing runways last minute) and increasing overall workload of controllers/pilots seems very risky.  If an aircraft accepts a delay; make them wait!  Don't change the overall operation to accommodate one; which in turn affects many.  If there is a lull in arrival traffic or a natural hole where the departure would fit; then by all means fill it.




Synopsis: Controller states that while operating in a busy arrival period; he was ordered to change the operation to allow an A88 depart opposite direction.  While doing so he has an operational error involving two arrivals.