The Wright/Smithsonian Controversy
Could the 1903 Langley
Aerodrome Have Flown?
 

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A History    
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The Wright/     Smithsonian    
Controversy 

Resolution 

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Smithsonian     Apologizes 

   Could the 1903    
Aerodrome    
Have Flown?
 
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Which Leaves Just One Final Question

 

lthough Charles Abbot's 1942 apology and retraction ended the feud between Orville Wright and the Smithsonian Institution, it did not answer the question that had started the mess. In his apology Abbot admitted that, because of the changes made to the aircraft, the 1914 experiments at Hammondsport did not prove that the Aerodrome ― in its original configuration ― was "capable of flight." So the question remains: Could the 1903 Langley Aerodrome have flown?

Beyond the politics, there was a contingent in Washington informally called the "Langley Society" that believed the original 1903 Langey Aerodrome could have made a sustained flight with a person aboard if it had been properly launched. Samuel Langley himself had claimed this was so shortly after the disastrous launch attempts of 1903. In the 1904 Annual Report to the Board of Regents of the Smithsonian Institution, Langley said emphatically "...the machine has never had a chance to fly at all, but that the failure occurred on its launching ways; and the question of its ability to fly is, as yet, an untried one...another flight would be successful if the launching were successful, for in this, and in this alone, as far as is known, all the trouble has come." Others concurred. In his report to the US Army Board of Ordinance and Fortification, Major M. M. Macomb said the 7 October 1903 "...trial was unsuccessful because the front guy post was caught in its support on the launching car." Of the 8 December launch attempt, he reported, "The rear guy post seemed to drag, bringing the rudder down on the launching ways and a crashing, rending sound, followed by the collapse of the rear wings, showed that the machine had been wrecked in launching."

However, the launching method may have not been the Aerodrome's only problem. Several aeronautical engineers have studied the 1903 Aerodrome and have concluded that it was not capable of flight because the structure was too weak and excessively aeroelastic.  That is, the structure could be easily distorted by the forces in play during flight. In their 1955 book Aeroelasticity, authors Raymond L. Bisplinghoff, Holt Ashley, and Robert L. Halfman observe "Perhaps the first designer to be affected [by aeroelasticity] was Professor Samuel L. Langley of the Smithsonian Institution. In light of modern knowledge, it seems likely that the unfortunate wing failure which wrecked Langley's machine on the Potomac River houseboat in 1903 could be described as wing torsional divergence."   In 1981, NASA engineers Wilmer Reed III, Rodney Ricketts, and Robert Doggett tested the wings of the newly-restored Langley Aerodrome and found that because of “overall lack of structural rigidity, especially torsional rigidity of the wing and fuselage, it [is] highly probable that the collapse of the machine during launch can be attributed to…overload due to elastic deformations.”

More recently, in 2004 Lorenzo Auriti and James DeLaurier of the University of Toronto built models of the Great Aerodrome wings and conducted wind tunnel tests. They found that during a launch the wings would twist with the leading edges down and the trailing edges up; the lower guys posts were subjected to loads beyond their breaking point, and the guy wires would "yield," depriving the spars of critical support. Their conclusion was "the Aerodrome was not capable of flight as launched off the houseboat [in 1903]. The wing loads found were higher than the structure could support."

According to these experts, the 1903 Aerodrome airframe had two fatal flaws. First, the wings would not hold their camber or angle of attack when the air was flowing over them. In the first few critical moments of flight, the wings twisted or deformed so they actually pointed the Aerodrome down. Second, the structure would not support the aircraft in flight, particularly during the stresses of a catapult launch. The lower guy posts would snap, the wires would go slack, and the spars would break where they joined the fuselage. Indeed, both of these flaws seemed to have manifested themselves in the two launch attempts of 1903.

If you closely examine the 1914-1915 Hammondsport trials, they support these conclusions. Ironically, the Smithsonian Institution claimed these same trials to have proved the Langley Aerodrome was the first aircraft capable of manned flight.  But a detailed review of the experimental results suggests just the opposite. Furthermore, the Hammondsport flights expose another potential flaw. That is, given the inefficient design of the wings and propellers, the available thrust may not have been sufficient to keep the aircraft in the air even if the airframe had been stronger.

The initial flights in late May and early June of 1914 plainly show that the Aerodrome (in its 1914 configuration) could not sustain flight with its original engine. When the Aerodrome reached flying speed, skimming across Lake Keuka on its pontoons, the pilot pulled back on the control lever to pitch the nose up. The airplane would leave the surface of the lake, but never for more than a few seconds. It would rise no more than 2 or 3 feet (0.6 to 0.9 meters) ― just enough for the pontoons to leave the water ― and continue for 100 to 150 feet (30 to 45 meters) before it settled back down on the lake. The standard procedure for this situation would have been for the pilot to hold the nose level or slightly down and let the airplane continue in "ground effect" (close to the surface where the air balls up under the wings and creates additional lift) while it gained enough speed to climb. Certainly Curtiss tried this, but the available thrust was not enough to gain speed or altitude, or even keep the aircraft flying in ground effect.

Clearly embarrassed by this lackluster performance, Curtiss claimed that the inability to sustain flight was due to increased weight. The pontoons, he said,  added 320 pounds (145 kilograms). The original Aerodrome had weighed 850 pounds; its Hammondsport reincarnation weighed 1170 pounds (386 versus 531 kilograms). It was a believable story, but it was not the whole truth. More important than excess weight was insufficient thrust. The Aerodrome's inability to fly was primarily due to the underperformance of its engine. The Manly-Balzer motor only produced about 35 horsepower, two-thirds of the power it had delivered in 1903. Curtiss had compensated for the lack of power as best he could, adding a modern ignition and carburetor to the motor and reshaping the propellers to make them more efficient. But it was not enough. Later tests would show that the reworked engine and propellers produced only 300 pounds of thrust (1335 Newtons), well below the 450 pounds (2002 Newtons) measured in 1903. Curtiss could not explain this to the public because it would have exposed the central lie of the Hammondsport trials. Despite press releases to the contrary, the Aerodrome, excepting its pontoons, was not the same aircraft Langley had attempted to fly in 1903.  There were, in fact, over 30 alterations, including the reworked engine and propellers. Much of the excess weight had nothing to do with pontoons. It was there because of the doubled-up spars, solid ribs, A-shaped wing supports and other parts that Curtiss had added or modified to strengthen the airframe.

Shortly after the trials on 5 June, Curtiss left Hammondsport for Buffalo, NY to organize a new factory. He asked Albert Zahm to take over the investigation of the Aerodrome, but he left instructions that clearly show that Curtiss understood the true problem. Instead of reducing weight, he had his crew remove the original engine and substituted an 80-horsepower motor and modern propeller. In September 1914, the Aerodrome began to fly, eventually reaching altitudes of 30 feet (9 meters) and traveling for up to 20 miles (32 kilometers). But that success was tainted for the simple reason that it was accomplished without the original motor.

So in March 1915, while Lake Keuka was still frozen over, Zahm and his team reinstalled the original engine, and then replaced the pontoons with skates. This reduced the weight of the Aerodrome to 995 pounds (451 kilograms), somewhat closer to its original weight.  (Although no one ever pointed it out, this experiment showed that the pontoons added just 145 pounds (66 kilograms) to the aircraft; airframe improvements had added the remainder.) On 10 March, Curtiss pilots made several take-off runs across the ice. The best measured flight was only 75 feet (23 meters) in length. Even without pontoons, the lightened Aerodrome could not sustain itself in the air. The motor, by the way, continued to misbehave as it had in 1914.

Curtiss and Zahm made one more attempt to test part of the Aerodrome's original configuration. Ever since the Aerodrome's rear wings had collapsed during the 8 December 1903 launch attempt ― and long before Bisplinghoff et al. ― the aviation press had suggested that the Aerodrome's frame was not strong enough to hold together in flight. Langley supporters had countered by claiming the fault was in the launching mechanism; it had caught the Aerodrome during both of the attempted launches. In his June 1914 letter to the New York Times, Griffith Brewer, a friend and business acquaintance of the Wrights,  questioned the validity of the Hammondsport tests and once again mentioned the weakness of the airframe. "Langley was under the mistaken impression that it was necessary to have extreme lightness and a large surface in order to fly," wrote Brewer. " The result was that he designed wings of very small strength..." In June 1915, possibly hoping to allay these suspicions or remove more weight, Zahm had workers remove the rear A-frame that had been added to better support the rear wings. They replaced it with a single vertical post similar to the original. The rear wings folded up on an attempted take-off, just as they had in 1903.

This was the experiment that Orville's brother Lorin Wright had witnessed. That January, in response to the newest patent suit the Wrights had brought against him, Curtiss had cited the flights of the Aerodrome at Hammondsport, arguing that other airplanes could have flown before the Wright brothers' Flyer. Lorin was in Hammondsport to spy on what Curtiss was doing with the Aerodrome. And although Curtiss' workmen confiscated Lorin’s photos, apparently hoping to cover up the results of the experiment, Lorin made a full report when he got back to Dayton. Word got out. 

Based on these results, it's hard not to conclude that the Aerodrome was fatally flawed. It is all but certain that the modern aeronautical engineers who have studied the aircraft are correct; the 1903 airframe was too flimsy. After all, Glenn Curtiss, one of the most savvy airplane designers in America at the time, would not fly the Aerodrome until he had reinforced the wings and changed the rigging so the bracing wires were in line with the centers of pressure. The one time his crew did revert to the original construction, the wings failed. It’s also apparent the wings and propellers were inefficient, unable to provide sufficient lift and thrust without a great deal of power. From the trials, we know that 35 horsepower was not enough to sustain flight, while 80 horsepower was. Somewhere between the two is a threshold ― just enough power to keep the aircraft in the air. Was this threshold at or below the 52 horsepower available in 1903 when the engine was running at its peak? It may have been, but it's just as likely it was not.
A Quick Comparison

The take-away from all of this is that it's very likely the 1903 Langley Aerodrome was incapable of flight, but not completely certain. The one thing we can say with certainty is that science suffers when mixed with politics. If the Hammondsport trials had been conducted without the agendas of  Glenn Curtiss and the Smithsonian Institution, we'd have better answers.
 


The Langley Aerodrome plunges into the Potomac River immediately after its launch on 7 October 1903. The photos made it apparent that the front wings had twisted, forcing the aircraft down. Engineers said it was too lightly built; the wings hadn't the strength to remain properly aligned. Witnesses said the front guy post had caught on the catapult. Both could be correct. Each guy post was attached to the airframe ahead of its respective main spars. The wires from the post to the main spars angled back slightly. If the bottom end of the post caught as it left the catapult, the top end would have been dragged forward, pulling on the wires attached to the spars. The wires would have wrenched the spars up and forwards, twisting the flimsy front wings so the trailing edges angled up and the leading edges down..

This photo was taken of the Aerodrome as it left the catapult. Note the position of the trailing edges of the forward wings compared to that of the one visible rear wing. The wings are twisted with the trailing edges well up. The beam just visible in the left side of the photo is the portion of the launch rail that Langley claimed to have caught the Aerodrome as it left the track.

Between 7 October and 8 December 1903, Langley's crew altered the catapult so it wouldn't catch the guy posts. They were only partly successful. On the second launch attempt the front guy post cleared, but witnesses aboard the houseboat reported that the rear guy post caught and the tail was "dragged to pieces" before the aircraft left the catapult. There was a pulley on the bottom end of the rear guy post through which a control wire ran to the tail. If the bottom section of the rear guy post caught and broke ― as Auriti's and DeLaurier's wind tunnel research predicted it might ― the tension on that control wire would have been released. If the part had stuck in the track, the tail would have been pulled down and then pulled apart as the aircraft continued forward. That same failure would have also released the tension on the guy wires, allowing the rear wings to fold up as the Aerodrome left the catapult and the wings took its full weight.

As this photo shows, the bottom end of the rear guy post was incredibly close to the launch track. It had only to drop a few inches to catch. And it might have broken even without catching. The quick acceleration by the spring-powered catapult created enormous stress on the airframe members, none more than the guy posts.

The Aerodrome just as it lifts from Lake Keuka near Hammondsport, NY for a very short flight on 2 June 1914. Curtiss had discarded the complex houseboat and catapult for simple pontoons as a way to launch the aircraft. Pontoons also provided a way to safely recover the aircraft and its pilot after the flight, something that was sorely missing from the 1903 launch attempts.

The Aerodrome ready for thrust tests on 9 March 1915. Lake Keuka is frozen over; the pontoons have been removed and replaced with skates.

The Aerodrome about to take off on 10 March 1915; the rear skate has not yet left the ice. Note that the right wings still display some "torsional divergence" even though they have been substantially strengthened.

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