1914 TESTS OF THE LANGLEY "AERODROME" — ABBOT 115 



CONTROL SURFACES 



16 Vane Rudder : A split vane com- 

 posed of two surfaces united at their 

 leading edges and separated 15" at 

 tlieir trailing edges, thus forming a 

 wedge. Each surface measured 2'3" 

 X 4'6", with aspect ratio .5. (L. M. 

 p. 214, pis. 53, 54). 



17 Operated by means of a wheel located 

 slightly iu front of the pilot at his 

 right side and at the height of his 

 shoulder (L. M. p. 216, pis. 53, 54). 



18 Used for steering only (L. M. p. 214). 



19 Pknaud Tah. : This was a dart- 

 shaped tail having a vertical and a 

 horizontal surfaces (Peuaud tail), 

 each measuring 95 sq. ft. It was 

 located in the rear of the main frame. 



20 Attached to a bracket extending 

 low the main frame. 



be- 



21 "Normally inactive", (L. M. p. 216) 

 but adjustable about a transverse 

 horizontal axis by means of a self- 

 locking wheel located at the right 

 side of the pilot, even with his back, 

 and at the height of his shoulder. 

 (L. M. pis. 51, 53). 



2U Immovable about a vertical axis. 

 (L. M. p. 214, pi. 50, Fig. 1.) No 

 means were provided for adjusting 

 this rudder about a vertical axis in 

 flight. "Although it was necessary 

 that the large aerodrome should be 

 capable of being steered in a hori- 

 zontal 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 surface un- 

 derneath the main frame measuring 

 3'2" in height by 6' average length. 

 Area 19 sq. ft. (L. M. pi. 53). 

 501591—43 9 



Veutical Rudder: The Langley vane 

 rudder was replaced by a single plane 

 vertical rudder which measured 3'6" x 

 5', with aspect ratio of .7. 



Operated at Hammondsport through the 

 Curtiss steering wheel in some tests, 

 (Zahm alBdavit pp. 5, 6), through the 

 Curtiss shoulder yoke iu some others 

 (Manly letter, 1914), and fixed so as 

 not to be operable at all in still others, 

 (Zahm affidavit p. 7). 



Used "as a vertical aileron to control 

 the lateral poise of the machine", 

 (Zahm afiidavit p. 6) as well as for 

 steering, (Zahm affidavit p. 7). 



Tail Rudde^i: Same size and construc- 

 tion as in 1903. 



Attached to same bracket at a point 

 about 8" higher than in 1903. 



Operable about a transverse horizontal 

 axis and connected to a regular Curtiss 

 elevator control post directly in front 

 of the pilot (Zahm affidavit p. 5). 



iujni.nable about a vertical axis on 

 May 28, 1914, only. Thereafter it was 

 made movable about a vertical axis 

 and was connected through cables to 

 a Curtiss steering wheel mounted on a 

 Curtiss control post directly iu front 

 of the pilot. 



Keel: Entirely omitted. 



