Stearman LT-1
The Stearman LT-1 was a late 1920s American biplane, carrying four passengers plus mail.
Design and development
The LT-1 was a slightly enlarged version of the Stearman M-2 Speedmail with four passengers in an enclosed cabin and space for of mail. It was an unequal span, single bay biplane, its lower span only 70% that of the upper and with only 40% of its area. The wings were built around twin spars so, because of the narrower chord of the lower wings, the leading members of the N-form interplane struts which joined the wing spars leaned forward. Both upper and lower wings were set with 2° of dihedral and both carried ailerons, which were externally interconnected. Navigation and landing lights, the latter in streamlined underwing housings, were standard.The LT-1 was powered by a Pratt & [Whitney Hornet] radial engine, nose-mounted with its nine cylinderheads exposed for cooling. Behind the engine there was a mail compartment and behind that a windowed cabin seated four passengers, provided with airspeed meter, altimeter and map box. Its pilot had an open cockpit with windscreen and streamlined headrest built into the rounded upper fuselage decking.
Its tail was conventional, with a tailplane mounted on top of the fuselage and a cropped triangular fin with a rather angular balanced rudder.
The undercarriage was also conventional, though with a tail wheel rather than a skid. Its mainwheels were on split axles and rearward drag struts, both mounted centrally on the fuselage underside, with vertical shock-absorbing legs.