The Thrill of Invention
A dedicated craftsman explores the invention of the airplane by recreating its predecessors.
- By Tom Crouch
- Air & Space magazine, May 1998
(Page 5 of 7)
Fortunately, one surviving photo shows the glider being flown as a kite. An image of the sad remains of the craft following an accident on October 10 also proved to be very useful. Young's finished glider weighs 65 pounds, 15 more than the original. Instead of lightweight pine he used tougher, heavier fir and substituted muslin of the sort used on all later Wright aircraft. The trussing cables and even the fittings, while closely patterned after what can be seen in the digitized photographs, are nevertheless heavier than those in the original.
Based on the Wrights' experience, Young never had much chance of achieving significant glides in the 1900 version, and even Jay was too heavy to be kited aloft. Like the Wright brothers, Young and his crew gathered performance data with a scale to measure the total force exerted on the aircraft. The results seemed to match the performance of the 1900 glider under similar conditions.
In the interest of safety, and in view of the complete absence of information on how the Wrights operated the warping system, the glider was rigidly trussed. The elevator was tested using a "dunking line," as the Wrights called it, leading from the elevator to a handler on the ground. As the Wrights reported, it was very effective.
1901: "When the time came to design our new machine for 1901," Wilbur wrote, "we decided to make it exactly like the previous machine in theory and method of operation." To improve upon the lift of the 1900 aircraft they used a less porous muslin wing covering, increased the curvature of the airfoil to match that on which the Lilienthal table had been based, and enlarged the wing area from 165 square feet to 290. It would be the largest glider ever flown. Operating from a new shed at the base of the Kill Devil Hills, the Wrights made 50 to 100 free glides and kite tests between July 27 and August 17, 1901.
Problems were apparent from the outset. On Wilbur's first attempt to glide, the machine nosed sharply into the sand after flying only a few yards. After a series of trials in which the pilot kept moving farther to the rear, he was finally able to complete "an undulating flight" of a little more than 300 feet. "It was apparent," Wilbur admitted, "that something was radically wrong."
The cause of the problem was the relatively thin ribs, which spanned almost five feet between the spars and were so flexible that they would bend at the midpoint. The airfoil changed shape, allowing the center of pressure to shift to the rear of the center of gravity and caused the aircraft to nose into the ground. The brothers devised a complex fix, trussing down the ribs of both the upper and lower wings. When testing resumed, the elevator proved far more effective. Flights in excess of 350 feet and lasting as long as 17 seconds were the order of the day.
As the flights grew longer, however, it was apparent that the new craft, like its predecessor, developed much less lift than had been predicted. Moreover, the brothers now encountered a new and quite unexpected problem with the lateral control system. In wing warping, the pilot increases the angle of attack on one end of the wing and decreases the angle on the opposite end. As flights grew longer, it became apparent that the wing on which the angle of attack was being increased would lose speed and drop, rather than rise. It was the first step in a frightening sequence of events that led to the aircraft spinning into the sand. "Well-digging," the Wrights called it.
The brothers left the 1901 glider packed away in the shed when they returned to Dayton. Back in camp the following year, they hauled the old machine outside so they could repair the damage done to the building by winter storms and straighten things up. Suddenly, a gust lifted the old glider into the air for the last time. "Machine raised off ground and came bouncing over & over towards the camp," Orville noted in his diary that evening. "Was stopped after going about 150 ft. and breaking one upper spar." The Wrights salvaged the uprights for use with the 1902 glider and abandoned the rest of the machine.