Because of import restrictions on American-built engines for some years after World War II, Auster Aircraft decided to fit a British-built engine (the Cirrus Minor) to an Auster Arrow airframe.
The three-seat Auster J-5 Autocrat was basically a more powerful version of the J-1 Autocrat but, unlike the similarly engined Aiglet and Alpha, the J-5 did not have the larger vertical tail surfaces provided on those aircraft to compensate for the extra power.
In 1962 Agricultural Aviation Pty Ltd of Archerfield, QLD, decided to convert an Auster J-5 Adventurer for agricultural duties, converting it from a three-seater to a single-seater, fitting an American Lycoming six-cylinder engine and installing a hopper in the rear of the cockpit and spray bars.
Following the success of the three-seat Autocrat, Auster’s chief designer, R E Bird used the experience gained from the design of the Alpha, which did not proceed to production in any numbers, and came up with a four-seater of similar specifications.
Despite the appellation ‘Aiglet’, the J-5F series was not derived from the J-1B Aiglet. The J-5F was basically a J-5 with a widened and strengthened fuselage to permit the Aiglet Trainer to be fully aerobatic, the only Auster to be fully certified in this role.
The J-5G was a more powerful variant of the J-5B and had some strengthening to allow the installation of a more powerful engine, this involving the fitting of several extra tubular front members.
The designation J-5H was applied to one aircraft (VH-ADS) and the designation J-5GL was applied to a J-5G which (ZK-CXA) was rebuilt in New Zealand to take a Lycoming engine. The J-5H was registered in Australia. This aircraft was built as a J-5B (VH-ADS - c/n 2047) and was imported
The Alpine series was introduced to the Auster range in 1955, being a development specially for operations from high-altitude airfields in hot climates.
The Auster series of light aircraft was developed from the Taylorcraft series of light cabin monoplanes designed in the United States by C Gilbert Taylor, who had emigrated from Nottingham, and produced by Taylorcraft.
In 1950 an Autocrat airframe was converted by Auster to J-1B configuration, being fitted with a Gipsy Major I engine and a larger horn balanced rudder.
Following the cessation of hostilities in World War II, the Auster company decided to develop the AOP-6 air-observation-post aircraft for postwar use by the RAF.
The Auster AOP-9 was designed specifically for the British Army Air Corps as an air-observation-post aircraft to replace previous Auster variants which had been civil designs converted to fill that role.
The Agricola agricultural aircraft was designed by the chief designer of Auster Aircraft Ltd, R E Bird, in the 1950s following a tour he made of New Zealand to examine the requirements of agricultural operators.
During the latter stages of World War II the Taylorcraft design team decided to build a lower powered version of the Auster Mk 5 and a prototype, originally known as the Taylorcraft Auster Mk 5 Series J-1 Autocrat, was built and flown.