Airmen vulnerable to deploy as part of the Silver Air and Space Expeditionary Force but not originally asked to go could end up going after all. Air Force Chief of Staff Gen. John P. Jumper said continuing efforts in the war on terrorism have created a need for additional support in some areas. The Air Force, he said, would be providing some of the support to fill that need. Nearly 2,000 airmen in those support areas will be called upon to help the Air Force meet the joint-sourcing challenge. Most will come out of already scheduled AEFs and should already know they are in or approaching their deployment eligibility window, said an AEF official. Many troops could expect to be deployed for about 90 days, but some in stressed fields could expect a 179-day rotation, he said.