Air Liaison With The Army Factors of all-round service ability combine to make the Westland Lysander monoplane of immense assistance in its primary duty of army cooperation. High-wing monoplane design permits excellent outlook for observation work, and the Lysander is fully equipped for day and night flying, bombing, radio reports, supply dropping, photography and other duties of liaison. Top speed of 229 m.p.h. (368,5 km./h.) is reached when fitted with a Bristol Mercury XII 890 h.p. (900 c.v.)