21 “Normally inactive,” (L.M. Operable about a transverse p. 216) but adjustable about a horizontal axis and connected transverse horizontal axis by to a regular Curtiss elevator means of a self-locking wheel control post directly in front located at the right side of the of the pilot (Zahm affidavit p. pilot, even with his back, and 5). at the height of his shoulder. (L.M. pls. 51, 53.) 22 Immovable about a vertical Immovable about a vertical axis. (L.M. p. 214, pl. 56, axis on May 28, 1914, only. Fig. 1.) No means were provided Thereafter it was made movable for adjusting this rudder about about a vertical axis and was a vertical axis in flight. connected through cables to a “Although it was necessary that Curtiss steering wheel mounted the large aerodrome should be on a Curtiss control post capable of being steered in a directly in front of the pilot. horizontal direction, it was felt to be unwise to give the Penaud tail and rudder motion in the horizontal plane in order to attain this end.” (L.M. p. 214.) 23 KEEL: A fixed vertical KEEL: Entirely omitted. surface underneath the main frame measuring 3′2″ in height by 6′ average length. Area 19 sq. ft. (L.M. pl. 53.) SYSTEM OF CONTROL. 24 LATERAL STABILITY: The LATERAL STABILITY: Three means dihedral only was used for were used for securing lateral maintaining lateral balance. balance at Hammondsport: The (L.M. p. 45.) dihedral angle as used by Langley, a rudder which “serves as a vertical aileron” (Zahm affidavit p. 6), and the Penaud tail rudder. The last two constituted a system “identical in principle with that of Complainant’s [Wright] combined warping of the wings and the use of the vertical rudder.” (Zahm affidavit p. 6.) 25 LONGITUDINAL STABILITY: LONGITUDINAL STABILITY: At Langley relied upon the Penaud Hammondsport the Penaud inherent system of inherent stability for longitudinal stability was maintaining the longitudinal supplemented with an elevator equilibrium. “For the system of control. preservation of the equilibrium [longitudinal] of the aerodrome, though the aviator might assist by such slight movements as he was able to make in the limited space of the aviator’s car, the main reliance was upon the Penaud tail.” (L.M. p. 215.)