British Royal Air Force Air Commodore Stuart Atha, air officer commanding of the 83rd Expeditionary Air Group, presents Staff Sgt. William Chesnutt, an air traffic controller from Marine Aircraft Control Group 28, with a British Certificate of Competency for air traffic control at Camp Bastion, Helmand province, Afghanistan, Sept. 9, 2009. Chesnutt is one of the first two Marines in British aviation history to receive the certificate, also known as the Blue Book.