"Pierce The Ethereal" - Saturday, September 20, 1902
The History: A small change was made in the vertical tail. Wire was used to secure the tail at the correct height.
They tested on a larger hill today. Orville wrote in his personal diary, "We were not able to determine effect of changing angle of wings, although it was apparent that the machine would not swing around the higher wing as it did last year." [When a bird turns it lowers one wing and turns in the direction of that lower wing. To make a right turn the right wing is lower, the left wing is higher. Sometimes the 1901 glider would turn in the wrong direction. The glider would turn in the direction of the high wing - just the opposite of what should have happened. The vertical tail was added in 1902 to change the aerodynamic forces and prevent this from happening.]
Wilbur made a 200 foot glide which lasted 11 seconds. The right wing was down and the left wing up. The glider started to slide towards the right. Instead of flying straight into the wind, the glider now was a little to the right of the wind. The wind rushed under the raised left wing forcing it even higher. While beginning to adjust the wing tips (to get the left wing down), Wilbur by mistake pushed the front rudder down [which would pitch the glider up]. Suddenly the glider charged up in the air at a very steep angle, over 45°, Orville reported. Orville wrote that the machine, "pierce the ethereal [the heavens]".
With the wind now at a 90° angle and the left wing even higher than it had been, the glider plunged down towards its right wing, Before reaching the ground the left wing dropped, but the right wing struck the ground first and spun around it, the wind now blowing from behind.
Later in the day, they tested how changing the torsion (twist) of the wings affected turning. Running with the machine down a small hill of 7° and raising one wing, the glider would turn around the lower wing, just as it should! Even when the wing blew from the direction of the lower wing [which could have prevented the turn].
Wilbur made the last maneuver of the day. A free glide of 140 feet from Little Hill at an angle of 7 1/6°.