Bristol Type 171 Sycamore Mk 1

Bristol Aeroplane Company · United Kingdom · first flew 1947 · helicopter

The Bristol Type 171 Sycamore Mk 1 is the prototype and initial development variant of Britain's first successful indigenous helicopter. Designed by Raoul Hafner's team at Bristol, it established the configuration that led to the production Sycamore used by the RAF.

Recognition (WEFT)

W — WingsHigh-mounted, rotary
E — Engines1 × piston, fuselage-mounted
F — FuselageSingle Alvis Leonides piston engine in fuselage nose
T — TailConventional

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Spot it by:

A conventionally configured single-engine helicopter with a three-blade main rotor, piston engine in the nose cowling, and a slender tailboom with a small anti-torque rotor; the squared cabin windows distinguish it from later marks.

Specifications

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

The Type 171 first flew in July 1947, powered by an Alvis Leonides radial engine. Early marks were evaluation aircraft; the Mk 1 and Mk 2 were pre-production examples that proved the design concept and led to the Mk 3 and HC Mk 14 production variants ordered by the RAF and other services.

Variants

The Type 171 series progressed through Mk 1, Mk 2, Mk 3, and the military HC Mk 14; the HC Mk 10 designation was applied to one specific export variant.

Where you'll see it

The Mk 1 served only as a trials and development aircraft; it did not enter operational service but paved the way for the production Sycamore used by the RAF, Royal Australian Navy, and Bundeswehr.

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