Colonel (Dr) Willis entered the U.S. Air Force Academy by direct congressional appointment and graduated with honors on June 6, 1973, receiving a regular commission as a second lieutenant. While attending the Academy he also completed the U.S. Army Basic Airborne Course (Ft Benning, Georgia) becoming a fully rated parachutist.
Upon his commission, Colonel Willis entered the Air Force Medical Service Corps and was assigned to attend Duke University School of Medicine as a fully sponsored student of the Air Force Institute of Technology. After receiving his medical degree in 1979, he then completed his specialty training at Andrews Air Force Base Maryland (89th Airlift Wing). After a short time on the academic faculty, he completed the U.S. Air Force Aerospace Medicine Primary Course (Brooks Air Force Base, Texas) becoming a fully rated Flight Surgeon.
Colonel Willis next spent three years at Bitburg Air Base, Germany (36th Fighter Wing) as the Chief of Medical Services and Chief of Emergency Services, and a short time assigned as the flight surgeon (aviation medicine specialist) for the 22nd Fighter Squadron, performing aircrew flight duties (F-15B).
Upon returning stateside in 1983, Colonel Willis had a four-year tour at Seymour-Johnson Air Force Base, North Carolina (4th Tactical Fighter Wing), first as Chief of Family Medicine and Chief of Emergency Services, and later as the Chief of Hospital Services (equivalent to civilian Chief Medical Officer) and Deputy Hospital Commander (equivalent to civilian Chief Operations Officer). He also performed flight surgeon aircrew responsibilities with the 336th Fighter Squadron (F-4E) and the 911th Air Refueling Squadron (KC-135A and KC-10), and was the Commander of the 4th Air Transportable Hospital – a completely mobile, palletized, 50-bed, 250-personnel forward-operating hospital with comprehensive medical, dental, mental health, and surgical combat capabilities to be deployed in response to wartime operations or humanitarian disaster relief efforts. During this time Colonel Willis was also certified as an Air Force Combat Medicine Instructor.
Next was a one-year assignment to Loring Air Force Base, Maine (42nd Bomb Wing), again as the Chief of Hospital Services (equivalent to civilian Chief Medical Officer) and Deputy Hospital Commander (equivalent to civilian Chief Operations Officer)., and Commander of the 42nd Air Transportable Hospital – a smaller mobile hospital of 50 beds and 150 personnel. He also performed flight surgeon aircrew duties with the 69th Bombardment Squadron (B-52H), 42nd Air Refueling Squadron (KC-135A), and the 101st Fighter Interceptor Squadron of the Massachusetts Air National Guard (F-15B).
In 1989 Colonel Willis returned overseas for three years as the NATO Clinic Commander (equivalent to Chief Executive Officer) at NATO Air Base Geilenkirchen, Germany, overseeing all healthcare operations delivered by the multi-nationally staffed unit supporting eleven Allied NATO nations assigned to the NATO E-3A Component of the NATO Airborne Early Warning Force Command. He performed flight surgeon aircrew duties with the Aircrew Training Squadron (707 Cargo Trainer) and Flying Squadron 1 (E-3A). During this time he deployed to the Southwest Asia area of combat during Operations Desert Shield/Desert Storm and commanded a multinational NATO clinic in support of international aircrew combat flight operations. He participated in several combat flight missions.
Colonel Willis returned stateside for two years as the Hospital Commander (CEO equivalent) at Columbus Air Force Base, Mississippi, a pilot training base (14th Flying Training Wing), where he also performed aviation medicine flight surgeon duties with the 37th Flying Training Squadron (T-37B) and 50th Flying Training Squadron (T-38A).
In 1993 Colonel Willis was assigned to Headquarters Air Education and Training Command at Randolph Air Force Base, Texas as the Deputy Director of Medical Services and Training and Chief of Professional Services, formulating and overseeing policy and guidance for quality improvement activities, personnel staffing, post-graduate medical training, and professional (medical/surgical/mental health) services for a network of 15 U.S. Air Force hospitals and clinics, comprised of 12,000 employees serving a population of over 500,000 patients. He also performed flight surgeon duties with the 558th Flying Training Squadron (T-43A), 562nd Flying Training Squadron (T-43A), 563rd Flying Training Squadron (T-43A), 332nd Airlift Flight (C-21A) , and 99th Flying Training Squadron (T-1A).
From 1995 until his retirement from the service, Colonel Willis was assigned to the Office of the Air Force Inspector General, Air Force Inspection Agency, Directorate of Medical Inspections at Kirtland Air Force Base, New Mexico. Initially, as the Chief of the Medical Inspections Division, he managed two teams of 12 healthcare personnel of various disciplines (medical/dental/mental health/nursing/administration/ancillary services) inspecting all 80 active U.S. Air Force hospitals and clinics worldwide. He also supervised the U.S. Air Force inspection management of over 450 radioactive sources under license/permit by the Nuclear Regulatory Commission. Later, as Chief of Operations Inspections, he managed a team of inspectors in the conduct of multi-disciplinary management reviews, functional assessments, and special studies of U.S. Air Force healthcare activities worldwide.
Colonel Willis has over 1,100 hours of flight time in numerous aircraft – in addition to those previously listed, he has had time in the C-123B, C-130H, C-141A, C-5A, F-16B, F-101B, F-106B, RB-66B, T-33A UH-1H, UH-1N, UH-60, and HH-60. During his military service, Colonel Willis graduated from the George Washington University Interagency Institute for Federal Healthcare Executives and the American College of Physician Executives Physicians in Management Course. He has also been certified by the Joint Commission for the Accreditation of Healthcare Organizations (JCAHO) as a Physician Surveyor.
He was a clinical consultant for Family Medicine to the Command Surgeon, U.S. Air Force Tactical Air Command (1983-1987) and the Command Surgeon, U.S. Air Forces Europe (!988-1991). He was also an administrative consultant for healthcare practitioner credentialing to the U.S. Air Force Surgeon General (1995-2000).
His military decorations include the Legion of Merit, Defense Meritorious Service, Air Force Meritorious Service Medal (with three oak leaf clusters), Air Medal (for combat air missions), Air Force Commendation Medal, Air Force Achievement Medal, Humanitarian Service Medal, and others.