be used by the Australian Defence Force; ten were delivered to the Royal Australian Navy. The Sycamore was also used in a variety of civilian roles. A single example was used during the construction of the M1 motorway between London and Leeds; the type provided support in various roles, including to perform aerial surveying, communication across various sites, the carriage of both personnel and equipment, and the mitigation of flooding on the project. Sycamores operated by Australian National Airways were routinely available for charter, performing tasks such as the aerial surveying of mining claims, supply missions, and the transporting of equipment across the remote Outback areas of the nation. Variants Type 171 Mk 1 Prototype; two built. Mk 2 Second prototype; one built. Mk 3 Production model with five seats in a widened fuselage, with a shortened nose to improve visibility. 23 built, including Mk 3A. Mk 3A Civilian version with additional freight hold, two built for British European Airways. Mk 4 This was the main production model and similar to the military version called Sycamore with a more powerful engine. 154 built. Sycamore Sycamore HC.10 (=Mk.3) one built for evaluation by the Army Air Corps as an air ambulance. Sycamore HC.11 (=Mk.3) four built for evaluation by the Army Air Corps, as communications aircraft. Sycamore HR.12 (=Mk.3A) four built for the RAF for evaluation as search and rescue aircraft. Sycamore HR.13 (=Mk.3A) two built with rescue winches for the RAF for evaluation as search and rescue aircraft. Sycamore HR.14 (=Mk.4) 85 built for the RAF, as search and rescue aircraft. Sycamore Mk.14 three built for the Belgian Air Force, for use in the Belgian Congo. Sycamore Mk.50 three built for the Royal Australian Navy, for search and rescue, and plane guard duties. Sycamore HC.51 seven built for the Royal Australian Navy, for search and rescue, and plane guard duties. Sycamore Mk.52 50 built for the German Air Force and Navy. Operators Civil operators British European Airways Australian National Airways/Ansett-ANA Jayrow Helicopters Flying Bulls In 2013 the Flying Bulls by Red Bull reinstated one Sycamore Military operators Royal Australian Air Force – Only two Sycamores were in service with the RAAF from 1951 to 1965. The two helicopters were used for general support duties at the Woomera Rocket Range in South Australia. Aircraft Research and Development Unit No. 1 Air Trials unit Royal Australian Navy 723 Squadron RAN 724 Squadron