Measurements and modeling of wake vortices reveal that the Federal Aviation Administration's (FAA) minimum separation requirements for departing aircraft are often overly conservative. If the separation times following heavy aircraft can be safely reduced, considerable savings will be realized. The Dallas/Fort Worth International Airport (DFW) experiences departure delays daily. Banks of departing aircraft often create a significant queue at the end of the runway, with aircraft waiting between 10-20 minutes to depart. Additional delays occur during weather recovery operations after the terminal airspace has been impacted by thunderstorms. This report produces projected delay and cost benefits of implementing reduced wake spacing for departing aircraft at DFW. The benefits are calculated by simulating aircraft departures during both clear weather and weather recovery operations, using current and possible reduced spacings. The difference in delay values using different separation standards is used to calculate a cost savings to the airlines. The benefits for a single day are extended to a yearly approximation based on the estimated number of days that the separation criteria could be safely reduced. Departure information from February 19, 2001 is analyzed for clear weather operations. The simulation reveals a savings of $4.7 million/yr when the separation criteria is reduced from the current practice of 110 seconds to 90 seconds. A further reduction in the separation criteria to 60 seconds pushes the maximum savings to almost $10 million/yr. The daily savings for a weather recovery operation is $19,600 for weather impacts between 15-60 minutes and a reduction in spacing fiom the current 110 seconds to 90 seconds. The average increases to $36,200 when the spacing is reduced to 60 seconds. Significant thunderstorm events impacted the DFW terminal airspace 59 times during 2001 leading to projected yearly savings of greater than $2.1 million for a 60 second separation criteria following heavies.