Drew received his commission as a second lieutenant from the United States Air Force Academy in May 1984. He completed Undergraduate Helicopter Pilot Training at Fort Rucker, Alabama, in 1985. His initial assignment was to the HH-3E, flying combat rescue missions. He later transitioned to the MH-60G and was assigned to the Air Force Special Operations Command. There, he flew combat missions in operations Just Cause, Desert Shield, Desert Storm and Operation Provide Comfort. He completed USAF Fixed-Wing Qualification in 1993, and the United States Naval Test Pilot School in June 1994. He has commanded two flight test units and served on Air Combat Command staff.