Percy Pilcher: Could he have beaten the Wright brothers?
03-11-2017, 11:01 AM
#1
Percy Pilcher: Could he have beaten the Wright brothers?
The video is 48 minutes long, but it's quite interesting and doesn't seem that long.
https://www.youtube.com/watch?v=efCMbwdhXjM
https://www.youtube.com/watch?v=efCMbwdhXjM
12-15-2017, 05:44 AM
#2
At the time of his death, Pilcher had zero experience flying a glider with movable control surfaces. He was still using weight shifting just like Lilienthal did for five years.
The problem is that weight shifting limits the size of a machine, which limits how it can be powered and what can be done with it. It was also very dangerous. Aerodynamic force is proportional to the square of the air speed, a fact known even before Newton. If you learn to handle, say, a 5 knot gust, what happens when you get hit with 10? The upsetting force is not double the force of the 5 knot gust, it is quadruple. But the ability to shift weight doesn't change at all. Lilienthal died when he got hit with a gust he couldn't handle. It was not his first crash.
The Wrights never built a hang glider; they used movable control surfaces, starting with a kite in 1899. Their big breakthough came in 1902, when they solved the problems of adverse yaw and spiral mode instability. Pilcher never even knew such things existed. He preceded the Wrights, but he followed Lilienthal. Instead of rejecting weight shifting for control, he tried to extend it.
Wilbur said, "It is possible to fly without a motor, but it is not possible to fly without knowledge and skill." He praised Lilienthal for "taking the flying problem into the open air where it belongs", but he rejected Lilienthal's use of weight shifting. He believed that the necessary skill would come from flying with movable control surfaces. It doesn't matter what Pilcher put on paper. One can speculate on what he might have done had he lived longer, but speculation is all it is. Pilcher was on the wrong track.
Jim
The problem is that weight shifting limits the size of a machine, which limits how it can be powered and what can be done with it. It was also very dangerous. Aerodynamic force is proportional to the square of the air speed, a fact known even before Newton. If you learn to handle, say, a 5 knot gust, what happens when you get hit with 10? The upsetting force is not double the force of the 5 knot gust, it is quadruple. But the ability to shift weight doesn't change at all. Lilienthal died when he got hit with a gust he couldn't handle. It was not his first crash.
The Wrights never built a hang glider; they used movable control surfaces, starting with a kite in 1899. Their big breakthough came in 1902, when they solved the problems of adverse yaw and spiral mode instability. Pilcher never even knew such things existed. He preceded the Wrights, but he followed Lilienthal. Instead of rejecting weight shifting for control, he tried to extend it.
Wilbur said, "It is possible to fly without a motor, but it is not possible to fly without knowledge and skill." He praised Lilienthal for "taking the flying problem into the open air where it belongs", but he rejected Lilienthal's use of weight shifting. He believed that the necessary skill would come from flying with movable control surfaces. It doesn't matter what Pilcher put on paper. One can speculate on what he might have done had he lived longer, but speculation is all it is. Pilcher was on the wrong track.
Jim
