No. 1 Aircraft Depot RAAF

No. 1 Aircraft Depot (No. 1 AD) was a maintenance unit of the Royal Australian Air Force (RAAF). Formed in July 1921 at RAAF Point Cook, Victoria, it moved to the nearby RAAF Laverton in March 1926. As well as servicing aircraft and other equipment, in its early years the depot supported survey flights in Australia and the Pacific region. Its strength increased from 350 staff in the 1930s to over 2,000 during World War II, when it assembled, tested and repaired aircraft ranging from Tiger Moths to Spitfires to B-17 Flying Fortresses. The depot also engaged in aircraft research and development. Shortly after the war it introduced the first jets into RAAF service. In 1961, No. 1 AD ceased airframe maintenance, but continued to service aero engines. By the 1970s its main focus was ground-based equipment, though it still handled some aircraft components. The depot was disbanded in December 1994, its functions having been taken over by other units and private contractors. At the time of its disbandment, it was the oldest RAAF unit in continuous operation.

Pre-war years
No. 1 Aircraft Depot (No. 1 AD) was one of the first units formed by the Royal Australian Air Force (RAAF) after the new service's establishment (as the Australian Air Force) on 31 March 1921. The original components of No. 1 AD became known as such in April 1921, though the unit did not formally come into existence until July that year. Prior to this it comprised two elements in Melbourne, one at Spotswood handling the aircraft and equipment of the Imperial Gift, and another at North Fitzroy that was responsible for motor vehicle repair. When No. 1 AD was officially established at RAAF Point Cook, Victoria, on 1 July, the Spotswood component was dissolved, while North Fitroy continued to operate as a detachment. The unit's inaugural commanding officer was Squadron Leader Bill Anderson, who was also in overall charge of Point Cook. In January 1922 the depot was organised into a headquarters and stores, aircraft repair, and engine repair sections. The vehicle repair section at North Fitroy was transferred to Point Cook that April. Point Cook's corrosive seaside atmosphere was however deemed an unsuitable long-term location for aircraft maintenance. In September 1921, the government purchased land at Laverton, near a railway station eight kilometres inland from Point Cook, for the express purpose of constructing a dedicated home for No. 1 AD as the "warehouse of the Air Force". The depot, staffed by eight officers and seventy-seven other ranks, relocated to the new base on 1 March 1926. It occupied a large hangar that included an administration block, which along with living quarters and ancillary buildings had cost £300,000 to build.

As well as receiving, assembling, testing and maintaining RAAF equipment, No. 1 AD was responsible for supporting research flights. In July 1927, it was the departure point for the Northern Survey Flight, comprising a De Havilland DH.50 and two DH.9s, which reconnoitered northern and central Australia under the command of the Chief of the Air Staff, Wing Commander (later Air Marshal Sir) Richard Williams. The following month, No. 1 AD formed a Papuan Survey Flight, consisting of two Supermarine Seagull III amphibious biplanes under the command of Flight Lieutenant (later Air Vice Marshal) Ellis Wackett, to photograph the Papuan and New Guinean coasts as far north as Aitape. Wing Commander Bill Anderson returned to command the depot from April to August 1929, handing over to Wing Commander Adrian Cole, who served in the post until December 1932. By the mid-1930s, No. 1 AD comprised some 350 staff, servicing a range of aircraft that included Westland Wapitis, Bristol Bulldogs, Hawker Demons, De Havilland Dragon Rapides, Avro Cadets, Avro Ansons, and North American NA-16s. Its commanding officers during this decade included Wing Commanders Frank McNamara (February 1933 to April 1936), Frank Lukis (April 1936 to January 1938), and Arthur Murphy (January 1938 to May 1940). To cope with a new policy of rapid expansion of the RAAF, a Recruit Training Section was formed under the auspices of No. 1 AD in March 1935; it was reorganised as Recruit Training Squadron on 1 September 1936. On 3 May 1937, Recruit Training Squadron acquired its own sub-unit, the Communications and Survey Flight, utilising Tugan Gannets and Dragon Rapides for ongoing photographic survey work.

World War II
Although many squadrons were raised at RAAF Station Laverton during World War II, the base's prime focus continued to be its aircraft depot. Following the outbreak of hostilities in September 1939, No. 1 AD began expanding to handle the RAAF's growing number of training and combat aircraft, among them De Havilland Tiger Moths, CAC Wirraways, Lockheed Hudsons, Hawker Hurricanes, and Curtiss P-40 Kittyhawks. The depot assembled and tested new aircraft, and ferried them to operational areas such as northern Australia and New Guinea. It was also responsible for the maintenance of in-service aircraft, including their engines, instruments, and armament. As well as RAAF equipment, No. 1 AD repaired damaged US aircraft such as B-17 Flying Fortresses. The depot undertook research and development on various types, including Supermarine Spitfires, CAC Boomerangs, and Wackett Woomerass. It also ran comparative performance studies on Spitfires, Boomerangs, Kittyhawks, Brewster Buffalos, and Mitsubishi Zeros.

In the case of the Boomerang, for example, 105 CA-12s were delivered to No. 1 AD for testing between July 1942 and June 1943. As soon as the aircraft started arriving, the depot commenced handling and armament trials that continued for six months, identifying and overcoming such issues as the aircraft's guns freezing at high altitudes, and unusual levels of carbon monoxide in the cockpit. Fighter aces Alan Rawlinson and Wilfred Arthur, along with a United States Army Air Forces pilot, conducted comparative trials between a Boomerang, a Kittyhawk, a Buffalo, and a Bell Airacobra. The depot began despatching the Boomerangs to their operational units in March 1943, and the following month performance tested a turbocharged version of the CA-14, though this model never entered production. No. 1 AD's Special Duties and Performance Flight was responsible for conducting performance trials during the early war years; in December 1943 it became a separate organisation, No. 1 Aircraft Performance Unit, which would evolve into the Aircraft Research and Development Unit (ARDU) in 1947. Among the depot's wartime commanding officers was Wing Commander John Lerew, who held the post from December 1942 until November 1943. During his tenure, after investigating the crash of a Vultee Vengeance, he designed a clip to prevent the accidental release of the pilot's safety harness, which was later adopted for all such harnesses. By January 1945, No. 1 AD's strength had increased to its highest level of 2,339 staff.

Post-war years
A Gloster Meteor jet made its first flight in Australia from Laverton in 1946. By May 1947, No. 1 AD had assembled the first De Havilland Vampire jet in Australia for its maiden flight. In October the same year, the first helicopter in RAAF service, a Sikorsky S-51, arrived at the depot. In 1950, No. 1 AD received the sole high-performance piston-engined CAC CA-15 to be built, which had been sent to be "converted to components" (scrapped). The depot took delivery of the first Australian-built English Electric Canberra jet bomber in July 1953. Shortly afterwards, it modified the three Canberras of No. 1 Long Range Flight prior to the unit taking part in the 1953 London-to-Christchurch air race. In September that year, the first Australian-built Sabre jet fighter was delivered. By 1961, when all airframe maintenance at Laverton was transferred to Nos. 2 and 3 Aircraft Depots, No. 1 AD had serviced forty-two different aircraft types throughout its existence. It continued to maintain aero engines, however, and began supporting telecommunications equipment as well. The engine repair facilities at No. 1 AD were closed down in 1968. Staff were transferred to No. 3 Aircraft Depot at RAAF Base Amberley, Queensland, to prepare for the introduction of the General Dynamics F-111C swing-wing bomber to Australian service and concentrate on maintaining the new aircraft's engines. No. 1 AD's focus thereafter shifted to ground equipment that supported navigational aids, air traffic control, telecommunications and motor transport for the Air Force and other sections of defence and government.

No. 1 AD was presented with a Queen's Colour on 6 November 1981. By September the following year its strength was down to 235 staff, but it pioneered the support of various new technologies for the Air Force, in fields such as electroplating, fibre optics, and electronics. It was also responsible for developing and testing components for the F-111, Macchi MB-326 and McDonnell Douglas F/A-18 Hornet jets. From 1986, restructuring and outsourcing began to impact heavily upon the RAAF's technical services. By the 1990s, No. 1 AD's functions had largely been taken over by other units and private contractors, and it was disbanded on 2 December 1994. It was, at the time, the oldest RAAF unit in continuous operation and, according to the RAAF Historical Section, the oldest continuously operating maintenance depot of any air force.