Concord creation

In the middle of fifties English corporation Bristol (in 1960 formed a part of ВАС corporation) and French «Sud aviation» (SNCASE) began independent investigation pointed at creation of supersonic passenger aircraft (SST). These investigations, conducted in France due to project «Super caravel» showed that cost of development of such airplane, big enough to ensure air transporting of useful economically feasible loading, was out of financial limits of any individually taken west aircraft organization. On the 26th of October 1962 French and British governments signed the financial-economical agreement on the joint “Concord” designing, building and testing. The day before English organization “British Aircraft” (BAC) and French organization «Sud aviation» (in 1970 formed a part of state association “Aérospatial” SNIAS) signed agreement on creation of joint English-French consortium. Englishmen took upon themselves 2/3 of propulsion systems works; Frenchmen were responsible for approximately 60% of airframe and its systems. At the same time organizations took upon themselves responsibility to organize and coordinate work of scores of English and French organizations, involved into creation. Jet engines with draught of 169,2 kHz, worked out for that airplane, were the result of propulsion engineering organizations Rolls-Royce (Great Britain) and  SNECMA (France) cooperation. Outlay sum for 8 year program equaled 170 millions pounds sterling and was distributed between countries in equal parts. But the existence of complex problems that had to be solved during the “Concord” creation process changed the initial financing plans. More then 1200 millions pounds sterling were spent during 14 years of creating such airplane. That is why the price for serial specimen equaled not 10 but 60 million dollars. One of the main “Concord” peculiarities was delta wing with the continuously changed span of wing sweep angle: from big value at heel (75-85°) to average measures at the end (50-65°), having got the name of “ogive”. To test such wing under the conditions of flight it was decided besides testing in wind tunnel, to build the airplane-analogue.
Such analogue was single-seated experimental airplane _BAC-221_ owned by British Aircraft. It has more modest (as compared to Concord) range of analyzed speeds – from landing up to 1700 km per hour, but probations started in May 1964 were dragged out.
Usage of ogive lowered the aerodynamic center mixtion during the sonic barrier overcoming, in order to keep airplane in balanced mode fuel was transferred to special centring tanks.  
The most interesting results in the process of airplane creation were received during its sail-plane fatigue thermal testing conducted in Toulouse in France and in Farnborough in England. Due to flight tests data it was cleared up that nose flap was able to heat up to 135 °С at temperature difference during the cycle of 15 minutes to the value of 145° С. At that, reload could change from +2,5 to -1,0.
In Toulouse these checkouts started at 1972 in the heat-chamber with 35 000 quartz heaters of total power equal to 30 000 kilowatt. 
Regulated heat up rendered flight thermal loading mode. At the same time frame was loaded mechanically by mean of power exciter through the lever hanger bracket system. Those investigations and overpatching enabled organizations to define technological lifespan for frame of 45 000 flight hours that means 12-15 years of aircraft operational life. Important “Concord” peculiarity consists in usage of the main electrical system of aircraft control. Strict mechanical link remained in reserve. Such decision was novelty in the use of civil aviation airplanes. In order to increase the reliability of systems work SST had 3 hydraulic systems: 2 main and 1 emergency systems. These systems secured work of steering areas hydraulic boosters, landing gear extension and gear retraction, control of front wheels at maneuvering at landing, hull fore-part travel up or down, secure efficiency of aircraft balance system fuel pumps and input and output engine devices adjusting. Since flight with supersonic speed demanded heightened fuel consumption as compared to subsonic airplane, “Concord” had 17 tanks with 119786 liters of fuel in fuselage and wings.  As well as frame _TU -144_, frame of “Concord” was assembled of milled panels. “Concord” frame, although it has flight life time 45 000 hours (that is 15 000 more than TU-144 has) enabled for less overloading (+2,5- -1) and this is the reason for rather substantial limits in possibilities during maneuvering at landing and approach operation. On the whole,  “Concord” does not yield to TU-144 (that weighed 10 000 kg more) in the respect of technical features.   
Another problem that is the bed field of vision from the cockpit in the takeoff and landing state was solved with deflection of forward fuselage down for 12,5°.