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Wright Brothers CoG Position


Andy J
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Given the issues we have from time to time regarding the optimum position for the centre of gravity on our models did the Wright brothers have an understanding in their early experiments regarding the necessity to achieve a balanced force between the fore and main planes to obtain sustained flight?

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Lots of info about the methodology the Weight Brothers developed in creating solutions of controlled flight and effectively the development of 3 axis control as we understand today. They were significant in there time for practical and empirical experimentation and developing formula that could translate into practical solutions to the problems and have subsequently been proven to have been remarkably accurate in there results. I am not sure if there was ever a definitive C of G program of formula development but they certainly had access to data from other experiments and documentation and through there own  practical approach I would imagine they had a considered and measured approach that for all intensive purposes could predict optimum mass and incidence to provide balanced and therefore controllable forces. The flight and subsequent developments of the Wright Flyer are merely the figure head of a significant contribution to understanding aerodynamics and flight stability behind it.

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Yes. They even built a wind tunnel (I believe the very first) to test various airfoil sections. It is remarkable what they achieved, virtually from scratch, simply by experimentation and trial and error. They did not build their powered flyer until they had worked at the basics and a way of steering ("wing warping") by making numerous manned flights with several gliders over about four years.

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Undoubtedly. The success of the Wright brothers came about as a result of a vast amount of research, both their own empirical and studying that of others. Their designs were aided by detailed mathematical calculations.

 

For example 1901 they tested 38 airfoil sections each 43 times as they adjusted the angle of incidence by a quarter of a degree. That year in a lecture in Chicago Wilbur described how the centre of pressure moved with the change of the angle of attack which shows that he understood how the centre of gravity must be set to accommodate such shifts.

 

That is from the book 'Wilbur & Orville', a detailed biography by Fred Howard.

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I think even Cayley, who was responsible for the first manned free (as opposed to tethered) flight 50 years before the Wright Bros first powered flight, must have known of the importance of the correct balance point. He was the first to identify the 4 basic forces involved in flight.  

 

The Wright bros real achievement was being the first to combine powered flight with a practical method of control of the aircraft. They even identified adverse yaw caused by the wing warping & countered it by using coupled rudder control.   

 

Also there were a number of people using weight shift controlled hang gliders before the Wrights who must have been aware of the importance of the balance point. 

Edited by PatMc
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          George Cayley had free flight gliders flying in 1804, not what you would think of as a glider today being more kite shape but never the less it had the basics for stable flight

   A plan can be had from Sarik hobbies for the 1804 glider and it can be flown 2 channel radio.

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After little bit more research I have found the full text of the speech by Wilbur Wright in 1901 that I referred to in my earlier response. In the published notes there is this page which shows some of the brothers' understanding of the position of the CoG:

 

image.thumb.png.0b641025fb2644b6f3aa5d1eae11b8d1.png

 

The reference to the 'rudder' in the final paragraph is in fact the canard fore-plane - naming conventions for the control surfaces had not then been standardised.

 

 The full text of the speech is available here

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Am I wrong, but I always thought, that the Wright brothers, bike engineers, could build stiff and light airframes, and (the genius bit), developed a light engine for its output?

And they used the output of their rivals, and predecessors for the aerodynamics.

Not for a moment suggesting they did not understand aerodynamics, mind. 

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Just have a brief flick though Wilbur's 1901 lecture speech I linked to above Don & it will give you an idea of the painstaking research they did. Of course they stood on the shoulders of those that came before, just as Newton said he did, but they contributed immensely to fundamental aerodynamic research.

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They did design & build their own engine.

Also they used the output from their predecessors & contemporaries but found that this was largely inaccurate or just plain wrong. In fact it was virtually only Cayley who provided measured & methodically derived aerodynamic data.

If they'd worked with carbon fibre bikes no doubt their airframes would have been stiffer & lighter but I think one of the few things they used from there bike building experience was the chain drives to the props. And one of the chains took an "8" shaped loop to give reverse direction drive to one of the props - i.e. the props were L & R handed to avoid yaw reaction.

 

Edited by PatMc
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The Wrights saw the development of a powered flying machine as a business venture & the first powered flight as merely a step in that development, which is why they took out a large number of patents on many features of their machines. Most of their would be competitors saw achieving the first powered flight as a means of making their name in history so took a very amateur sporty approach . 

The Wrights didn't have the wealth or wealthy patrons of most of their predecessors & contemporaries so expected to expand their existing business to building aircraft with military customers & in fact offered to sell them to several governments.

 

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         One of those wealthy types Samuel Langley secretary of the Smithsonian contested for many years that the Wrights were first, stating his Aerodrome aircraft which launched from a houseboat on the Potomac river in October 1903 was first despite the fact it went just a very short distance before flopping into the river. The US military had contributed many thousands of dollars to this project.

             Such was Langley's influence that the Smithsonian did not recognise the Wrights as first in controlled powered flight until 1942!!!  Because of this up to that time a composite Flyer one [ made of spare parts ] was displayed at the Science museum London until just after WW2 When it returned to America.

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We visited Kitty Hawk about 20 years ago and the museum is well worth a visit.  I was expecting a MAGA hype attitude but I couldn't have been more wrong. It was more like Shuttleworth collection with a load of enthusiastic volunteers only too pleased to help with any queries.

 

Kill Devil Hill, where a lot of the hang glider experiments were carried out, is a huge sand dune which once was prone to natural movement because of the effects of wind but has been stabilised and there's a monument to the Wrights on the top.  We cycled up the track on a borrowed tandem just for the hell of it - I wonder if we're the only ones?  No-one said anything about it.

 

The route of that famous photographed first flight is marked, of course, and takes very little time to walk.  Apparently, the Wrights set up the camera and an assistant operated the shutter.  It was the first (and only?) photograph he ever took.  There must be millions of copies reproduced in magazines etc.  In fact I bought a copy there and it's on my workshop wall now.

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18 minutes ago, Geoff S said:

The route of that famous photographed first flight is marked, of course, and takes very little time to walk.  Apparently, the Wrights set up the camera and an assistant operated the shutter.  It was the first (and only?) photograph he ever took.  There must be millions of copies reproduced in magazines etc.  In fact I bought a copy there and it's on my workshop wall now.

John Daniels was the person who took the photo, he died the day after Orville. NALOPKT 

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40 minutes ago, Geoff S said:

We visited Kitty Hawk about 20 years ago and the museum is well worth a visit.  I was expecting a MAGA hype attitude but I couldn't have been more wrong. It was more like Shuttleworth collection with a load of enthusiastic volunteers only too pleased to help with any queries.

 

I visited the Wright Brothers Museum in Dayton, Ohio about the same time and had a very similar experience, the place was very quiet but was staffed by an enthusiastic Ranger who opened up the replica bicycle workshop next door just for me. I was there again in 2016, making a diversion on the way home from Oshkosh.

 

Ohio has a very rich aviation heritage with Neil Armstrong also being born in that State. The Armstrong Air & Space Museum, the Wright-Patterson Museum of the USAF and the Wright Brother Museum are must visits for any Total Aviation Person. 

 

 

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Yes.

 

The Wright brothers looked extensively as to the best place to conduct their flight trials. They settled on Kitty Hawk, some 530 miles from Dayton as the crow flies. They made annual trips there from their home in Dayton Ohio from 1901, travelling by train via Norfolk, Virginia to Elizabeth City, North Carolina. They then hired a boat for the 30 mile crossing of Albermarle Sound to Kitty Hawk. Each trip took up to a week's travel.  

 

Their aircraft was sent in kit form, created up and assembled on site. The first two years when they made gliding trials they lived on site in tents for 3 months but for 1903 they assembled two large wooden camp buildings. The flying almost seems to have been the easiest part of the exercise!

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Not wishing to take anything away from the Wrights. They certainly achieved many firsts.

 

I believe that the major step (as others have stated) was to build a light weight engine, that was capable of providing sufficient power for their purpose.

 

Others have also highlighted that others had identified much that was known and not known with respect to airfoils. Many others had taken inspiration from birds wing geometries. Others also got things wrong. The Wrights did sort a lot of the wheat from the dross.

 

The comment that some one made in that the Wrights were Professional in approach is certainly very true. I would add that they were also very commercially aware. To that extent the patents were not mere vanity acquirements, they were sought for financial exploitation. It should be noted that apparently a number of granted patents, were later rescinded, when contested on the grounds of Prior Knowledge.

 

From what has been said it appears our USA friends have not been jingoistic.

 

I think it is worth considering how history is not always quite as written. I recently went to Oslo and visited this exhibit https://en.wikipedia.org/wiki/Ægidius_Elling, I was already aware of this man https://en.wikipedia.org/wiki/John_Barber_(engineer). I also was aware that Brown Boveri of Switzerland had also built one (for the steel industry, running on town gas), that was found to be inefficient to the then alternatives.

 

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9 hours ago, Erfolg said:

It should be noted that apparently a number of granted patents, were later rescinded, when contested on the grounds of Prior Knowledge.

 

According to Wikipedia the Wrights' patents were upheld not rescinded - 

 

In January 1914, a U.S. Circuit Court of Appeals upheld the verdict against the Curtiss company, which continued to avoid penalties through legal tactics. Orville apparently felt vindicated by the decision, and much to the frustration of company executives, he did not push vigorously for further legal action to ensure a manufacturing monopoly. In fact, he was planning to sell the company and departed in 1915. In 1917, with World War I underway, the U.S. government pressured the industry to form a cross-licensing organization, the Manufacturers Aircraft Association, to which member companies paid a blanket fee for the use of aviation patents, including the original and subsequent Wright patents.[105][106][107] The "patent war" ended, although side issues lingered in the courts until the 1920s. In a twist of irony, the Wright Aeronautical Corporation (successor to the Wright-Martin Company), and the Curtiss Aeroplane company, merged in 1929 to form the Curtiss-Wright Corporation, which remains in business today producing high-tech components for the aerospace industry.

Aviation historian C.H. Gibbs-Smith stated a number of times[108][109] that the Wrights' legal victory would have been "doubtful" if an 1868 patent of "a prior but lost invention" by M.P.W. Boulton of the U.K. had been known in the period 1903–1906.[101][110][111] The patent, titled Aërial Locomotion &c, described several engine improvements and conceptual designs and included a technical description and drawings of an aileron control system and an optional feature intended to function as an autopilot.[112][113] In fact, this patent was well known to participants in the Wright-Curtiss lawsuit. A U.S. federal judge who reviewed previous inventions and patents and upheld the Wright patent against the Curtiss company reached the opposite conclusion of Gibbs-Smith, saying the Boulton patent "is not anticipatory".

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