Message posted by JB737 on December 12, 2007 at 4:29:03 PST:
The takeoff might work, but the landing would be scary. :-) I see a few technical problems with the idea which lead to very very high cost: 1. Tunnel cost goes up tremendously with the width of the tunnel (except for shallow ones not needing to support much weight above, but then this allows detection during construction or by IR, etc). This is why wide tunnels tend to be multiple tubes. Figuring out how to have the fuselage and wings go down 3 separate tunnels would make the tunnels cheaper but the aircraft more expensive shall we say. So tunnels are more practical if you can think up a smaller, more symmetric, wingless craft shape suitable for zipping out of a cylindrical tunnel. 2. Landing into a little hole is a major problem. While there is some similarity to a carrier landing, a go-around is easier to do through air than through dirt. And a crashed plane being pushed off the deck into the ocean stops a fire rather effectively, while a fire in a tunnel is a nightmare. Having said all that negative stuff, launching from a tunnel does remind me of some mass-driver ideas regarding launching payloads into space via acceleration in an inclined tube/tunnel, preferably one with the air removed down to vacuum to allow high speed without air resistance until exiting through a shutter or membrane. If this idea ever comes to fruition, the price of real estate on certain mountains like Chimborazo should go up sharply. JB737
In Reply to: Underground Runways posted by Am-241 on December 11, 2007 at 23:26:58 PST:
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