AFC Imperial Force Army Badge
From the Official Army Colour Patch Register;
The triangle has a 2" base and the other two sides are 2 1/4" long. The colours are Light Blue, Red and Dark Blue. The Dark Blue band is 1/4" wide and the Red bands are 1/8" wide. There is no surrounding colour. These patches were made from felt and should be warn on both shoulders. The AFC Patch was authorised by D.A.G. A.I.F. 15/67 of 10 July 1917.
All AIF formations had these patches in both World Wars and they have re-introduced them to the current Australian Army. The colour and shape of the patches were authorised in a consistent pattern during World War I, but during World War II the consistency was lost to an extent. It was possible to know during World War I which unit, such as Battalion, Regiment, Brigade or Division a soldier was serving with, by looking at the patch.
Modern Australian Army Aviation Badges
With Vietnam, the Air Force and Navy supplied the helicopters which supported the Australian Army. The Army however, wasn't impressed with the Army Support they got from the Air Force, despite being impressed with the support from the Air Fore's fixed wing aircraft. It was decided to give the Army Co-operation aviation squadrons to the Army to manage themselves. The current Australian Army Aviation (AAVN) Badges, which are a part of the Army Standing Orders for Dress, show homage to their Australian Flying Corps roots.
Royal Australian Air Force
The Royal Australian Air Force have also maintained a link to the Australian FLying Corps Army Badge with the Chief of Air Force's Flag. It depicts a golden eagle above the sky bue, red and royal blue of the Australian Flying Corps badge.
The information from the Official Army Patch Register and the AAVN Army Badges courtesy of Gordon Branch.
Australian Flying Corps : A Complete History of the Australian Flying Corps