Dispatch Dispatcher
Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Procedure; Human Factors
The [Duty Manager] allowed two flights with the same flight numbers to launch and be in the air at the same time.  We were notified of this; and subsequently changed [one of the flight numbers] to a flight number that should have been given to the aircraft in the first place (prior to launch).Preventative Measures: Possibly give the [Duty Manager] some type of automation tool that would bring to their attention that two flights with the same flight number have the potential for being in the air at the same time.
Air carrier Dispatcher reported discovering there were two Company flights with the same flight number in the air at the same time.