Date: 201602
Local time of day: 1801-2400
Location: DCA.Airport, DC
Flight conditions: IMC
Weather elements / visibility: Fog; 1/4
Light: Night
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZDC
ATC / advisory: Center ZDC
Reporter organization: Air Carrier
Reporter function: Dispatcher
Reporter qualification: Dispatch Dispatcher
Human factors: Communication Breakdown; Confusion; Situational Awareness; Workload
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
Detector: Person Dispatch; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Weather; Company Policy; Procedure; Airspace Structure
Primary problem: Procedure

Narrative: Although the original alternate selected for this flight was RIC; I decided for operational considerations to change the alternate to BWI when the flight crew advised me that they were diverting to RIC due to IMC/tailwind conditions at [the original destination]. Crew replied that ATC had advised them on numerous occasions that BWI was not accepting any diversions. I asked the ATC coordinator to call ATC and ask them why they would not allow my flight to divert to BWI. He was told by BWI ATC Tower that the airport was open; and they would accept any of our flights. After PIC maintained that ATC would not let him divert to BWI; the ATC coordinator called DC Center who advised him that there was some miscommunication between the Controller and the PIC. Controller allegedly thought the flight wanted to divert to DCA not BWI. After multiple ACARS exchanges with the crew relating to this matter; Captain informed me that he was diverting to his original alternate RIC. By that time he was committed anyway as he was already halfway there. After the flight landed; Captain called me to explain why he could not go to BWI. I informed him of the 'miscommunication' issue ATC was claiming. Captain proceeded to tell me that I was given the wrong information. He confirmed that ATC informed all flights holding for DCA at three different times that diversions to BWI were not allowed. ATC was clearly adamant about it. The event occurred because ATC was overstepping its authority. If an airport is open to landings; as confirmed by BWI ATC Tower; I do not see why ATC Center would keep any flight from diverting to that airport. Why do we need dispatchers if ATC steps in and takes over operational control whenever they feel like it? Flight landed in RIC with only 3900 lbs of fuel on board; which is below min dispatch for [our carrier]. This was due to the confusing and conflicting information given by ATC; followed by their decision to send the flight to RIC instead of BWI.ATC should be briefed on the scope of their authority and be exposed to the regulations outlined in FAR 121.533 (operational control). I do not believe they have a full understanding of our responsibilities as dispatchers. This is the second such incident in recent weeks; and both occurred in DC Center airspace.




Synopsis: Dispatcher reported confusion with ATC when a flight needed to divert; but ATC would not allow the aircraft to divert to the airport the Dispatcher had chosen.