Avro 521

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Contents

Type Description

• Type 521
• Two seat, single bay biplane, derived from the Type 504A, and, per Harlin and Jenks [2], most likely intended as a high speed observation machine. The fuselage was similar to the Type 504A, but the top longerons reverted to being horizontal, as on the 504 prototype. The observers cockpit was moved one bay aft and both cockpits used the streamlined headrest from the Avro 519. A new single axle V-type undercarriage was fitted, without the earlier aircraft's ash skid, the V legs attaching to the fuselage at the same locations previously used by the skid mountings. Standard Avro 504 mainplanes were used, shortened in span, cut away at all four wing roots to improve upward and downward vision and rigged with only a single set of interplane struts on each side. The wings retained the same stagger as the 504A, but the centre section struts were splayed one bay forward and aft. Tailplane and tail skid were as the 504A. One 110 h.p. Clerget powerplant.

• Type 521A
• As Type 521 with three bay mainplanes of larger span.

Production Details

Notes

1. 25 Avro Type 521 aircraft were ordered, although it appears only c/n 7520 was completed. It is likely that all those airframes built were converted to 504Es.

Production References

1. Avro Aircraft Since 1908, A.J. Jackson (Putnam, 1990)
2. Avro An Aircraft Album, E.A. Harlin and G.A. Jenks (Ian Allen, 1973)
3. http://www.airhistory.org.uk/rfc/aircraft.html