The Avro Anson, affectionately known as “Faithful Annie”, originated from the Avro 652 commercial monoplane, designed for Imperial Airways in 1933. This initial design, led by Avro designer Roy Chadwick, was a four-passenger charter aircraft powered by two Armstrong Siddeley Cheetah radial engines, intended for a cruising speed of 150 mph and a range of 600 miles. The Avro 652 featured a one-piece wooden mainplane moved from a high-wing to a low-wing position, a welded steel tube fuselage rounded out by fabric over wooden formers, and an innovative retractable undercarriage housed in streamlined engine nacelles. The landing gear was manually operated, requiring 140 turns of a chain-driven screw gear for retraction. The civil 652s, “Avalon” and “Avatar,” entered service with Imperial Airways in March 1935, flying the Croydon-Brindisi route.

Transition to Military Service and Design Evolution: Before the first Avro 652 was completed, the Air Ministry requested Avro propose a twin-engine landplane for coastal reconnaissance. The 652’s design was easily adapted, leading to the Avro 652A military version. This prototype, K4771, first flew on March 24, 1935. It differed from the civil 652 by having a door on the starboard side, square cabin windows, and initially a gunner’s position or a hand-operated turret. The 652A was also offered with a bomb load of 360 lb. in the center section and a single Vickers gun for the pilot on the port side. After competition and trials, the Avro 652A was adopted as standard equipment, and a contract for 174 aircraft was placed in May 1935, leading to its designation as the Anson Mk. I. The Anson name honored Admiral of the Fleet George Anson.

Key Design and Construction Features: The Anson was a conventional low-wing, twin-engine, cantilever monoplane.

• Wings: The single-piece cantilever monoplane wing consisted of two box-spars of spruce and plywood construction with plywood and spruce ribs and plywood covering. Bakelite plywood, known for being stronger and impervious to water, was used throughout. Portions aft of the rear spar, carrying flaps and ailerons, were detachable for transport. Later versions, like the Anson C19, introduced an all-metal wing.
• Fuselage: It featured a rectangular welded steel-tube structure with rigid bracing, covered with fabric over wooden fairings. Canadian-built versions (Anson II, V) introduced a moulded plastic-plywood nose and, in the Anson V, a new fuselage primarily of plastic-plywood construction to conserve steel.
• Tail Unit: The fixed tailplane and rudder were constructed of spruce frames with plywood covering, similar to the wing. Elevators and the integral fin were of welded steel-tube construction with fabric covering. Trimming tabs were included in the rudder and elevators.
• Landing Gear: It was a retractable type, consisting of two separate units mounted under each engine nacelle, into which they retracted. The Anson I featured manual retraction, requiring 140 turns. Canadian models and later British versions incorporated hydraulically-operated landing gear and flaps. A non-retractable castoring tailwheel was standard.
• Accommodation: The pilot's seat was in the extreme nose on the left side, with provisions for removable dual controls. Behind the pilot was the navigator/bomb-aimer's seat with a table and instrument panel. The bomb-aimer's position in the nose on the right side included a sliding floor door for using a Wimperis course-setting bomb-sight and bomb release controls. A wireless-operator/gunner's seat was located further aft. Crew access was through a door on the right (starboard) side of the fuselage.
• Armament: The Anson I was initially armed with one fixed forward-firing Vickers .303 in. machinegun in the port side of the nose and one Lewis or Vickers K .303 in. gun in an Armstrong Whitworth manually-operated turret amidships. Internal stowage was provided for two 100 lb. bombs, with external racks for eight 20 lb. bombs, flares, or smoke-floats. Maximum bomb load was 360 lb., though it could carry two 250 lb. bombs externally. Later armament trainers were fitted with a Bristol Mk. VI hydraulically-operated turret.

Dimensions, Weights, and Performance (Anson I): The Anson I had a span of 56 ft. 6 in. (17.20 m.), a length of 42 ft. 3 in. (12.90 m.), and a height of 13 ft. 1 in. (4 m.). Its normal loaded weight was 7,665 lbs. (3,476 kg.), with a maximum permissible loaded weight of 8,000 lbs. (3,627 kg.). Over its service life, the all-up weight steadily increased from 7,342 lb. for the prototype to 9,850 lb. by 1943. The Anson I had a maximum speed of 188 m.p.h. (303 km.h.) at 7,000 ft. (2,130 m.) and a cruising speed of 158 m.p.h. (252.8 km.h.) at 6,000 ft. (1,830 m.). Its service ceiling was 19,500 ft. (5,948 m.), and it had an initial rate of climb of 750 ft./min. (229 m./min.).

Roles and Service History: The Anson I entered service with the R.A.F. in 1936 as a General Reconnaissance monoplane for Coastal Command. Despite being considered obsolescent for front-line combat by the outbreak of WWII, Ansons participated in early engagements, including anti-submarine patrols and even shooting down enemy aircraft. They were eventually replaced in front-line duties by more capable aircraft like the Lockheed Hudson and Armstrong Whitworth Whitley by late 1941.

The Anson gained its most prominent role as the standard twin-engined trainer for the Commonwealth Air Training Plan (BCATP), primarily organized in Canada, Australia, South Africa, Southern Rhodesia, and New Zealand. It was used to train pilots, observers, wireless operators, and bomb aimers. Canada undertook large-scale production of the Anson II, III, V, and VI, setting up Federal Aircraft, Ltd. for this purpose. British production continued for domestic needs, covering Marks I, X, XI, and XII.

The Anson also served in various specialized roles:

• Light Transport and Communications: Ansons were converted for these duties, particularly the Anson X, XI, and XII, with the Anson X specifically designed for freight. They were crucial for the Air Transport Auxiliary (ATA) for ferrying pilots and light loads.
• Air Sea Rescue: Some were fitted with early ASV radar and served with Air Sea Rescue Squadrons until 1942.
• Special Duties: Including agent recovery and radio counter-measures.
• Civilian Use: Post-war, many surplus Ansons were converted for civil use as charter aircraft, freight carriers, survey planes, and ambulances. They served for decades in various capacities, including agricultural work and communications for oil companies.