Reaction Engines plan Mach 5 Airliner

What is? writes "A British company has designed an eco-friendly airliner that could make a trip from London to Sydney in under five hours. Reaction Engines has received funding from the European Space Agency to design the plane as part of the Long-Term Advanced Propulsion Concepts and Technologies project. The A2 airliner would be capable of carrying 300 passengers at speeds of up to Mach 5."

Comments

CG is Cheap

[Anonymous Coward]

I've seen more computer generated designs for supersonic passenger aircraft than I can count.

Is this going to be a real commercial jet, or just another cock tease?

Oh, won't somebody please think of the math

[Ancient_Hacker]

I'd love to see how they can make an "eco-friendly" airliner that goes Mach 5. There are some really basic laws of aero and thermo dynamics that put the kibosh on most of these schemes. Look at the Concorde, XB-70, SR-71, for examples of how difficult and expensive it is to design, test, and operate anything going Mach 2 to Mach 3.3. And the problems just go up from there, often by squares and cubes.

Re:Oh, won't somebody please think of the math

[reemul]

Right. We'll just step up production from our vast hydrogen mining industry. Oh, wait. We don't have anything like that. Mostly we get hydrogen from water, which often means running an electric current through it. Since US enviros oppose nuclear, won't allow new dams for hydro because it upsets the fish, and have fought new natural gas exploration for fear it will damage pristine ecosystems, that probably means that coal is being burned to produce that electricity. Nice, clean, eco-friendly coal. In fact, because of losses creating the hydrogen and then burning it in the engine, it's less efficient than the coal plant, so you have to burn more coal for the energy used.

Hydrogen is eco-friendly *at the point of use*, but unless someone can magically cause it to appear its production isn't environmentally sound at all. You just hide the costs and emissions somewhere that the public hopefully won't notice it. (Same with electric cars. Using electric doesn't pollute. Making it certainly does. Anyone telling you different wants your money or your vote.)