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...aerodynamically stable at Mach 1.2

Dude, your car goes 206 MPH? That's one hell of a speeding ticket...

Because it would appear sound travels awfully slowly in your vicinity... For the rest of us, the speed of sound (Mach 1) is a little under 770 MPH, and Mach 1.2 would be 900+ MPH.[1]

The citing officer would have to have a hell of a squad car... I guess that'll be the end of the Ford Crown Vic franchise -- they'll be underbid by Lockheed Martin.

Ole

[1]: Speed of sound through air at sealevel, assuming "average" ambient temperature, pressure, and humidity, is roughly 761 MPH. See FREX the aerospace web faq.

But that's the point. Airships are steered completely differently from airplanes. This is common misunderstanding. Airships turn like boats with a rudder.

An airplane cannot be turned with a rudder. If you try it, the airplane will just skid sideways through the air. Airplanes turn because they bank. To bank you use ailerons, and the rudder is needed to balance the turn (look up adverse yaw).

The Wrights discovered this with their glider experiments, and devised a mechanism to allow an airplane to execute a balanced turn. No one else had any idea.

This one has a wingspan of 290 feet.

This implies that somewhere there's a pair of aircraft hangar doors more than 290 feet wide.

Surely there's not many hangars capable of hiding this kind of beast (unless it somehow folds up like Optimus Prime, but it doesn't)

And according to this extremely fine, semi-technical and detailed article what has to happen to allow Pink Floyd to tour (I believe this to be absolutely authoritive, given the context), the largest aircraft hangar in the world is at Norton Air Force Base in San Bernadino, California.

And, despite my best efforts, I can't find a single reference to just how big the doors on -any- hangar at that place are.

Bummer.

The Hiroshima bomb destroyed most buildings within a mile, so that's a two-mile diameter, so you'd need about five Hiroshima-sized bombs to have a significant blast effect over an area five miles across. That's 15 kilotons, so you'd need 15 x 5 = 75 kilotons, or 75,000 tons, or 150,000 pounds of conventional explosive. (Yeah, it might not snuff the fire, but the updraft under the mushroom cloud will tend to suck the fire inward and slow its outward travel -- ignoring the effect of flying flaming objects)

Maybe five aircraft would be more practical, but let's see if one can do it. It looks like a 707 or KC-135 can handle 150,000 pounds and have capacity for some fuel weight. I don't know what the safety requirements would be to allow unmanned flight for civilian use of something like that.

Now, about the foam.. The area of a circle 2.5 miles in diameter is 547 million square feet (pi * r^2), so if you're going to cover just the surface (not trying to cover all branches on trees) to a depth of one foot, you need 547 million cubic feet of foam.

One Goodyear Blimp has 202,700 cubic feet of helium, so we'll assume it can hold that much foam.

So, fill a 707 with explosives and strap around it 2,700 Goodyear Blimps full of foam. Probably want to add some more, as some of the foam will be vaporized by the blast. Well, might be easier to just drop the blimp-sized bags of foam separately. There ya go, it's all designed. The rest is just engineering.

So, why doesn't it exist yet?

The Hiroshima bomb destroyed most buildings within a mile, so that's a two-mile diameter, so you'd need about five Hiroshima-sized bombs to have a significant blast effect over an area five miles across. That's 15 kilotons, so you'd need 15 x 5 = 75 kilotons, or 75,000 tons, or 150,000 pounds of conventional explosive. (Yeah, it might not snuff the fire, but the updraft under the mushroom cloud will tend to suck the fire inward and slow its outward travel -- ignoring the effect of flying flaming objects)

Maybe five aircraft would be more practical, but let's see if one can do it. It looks like a 707 or KC-135 can handle 150,000 pounds and have capacity for some fuel weight. I don't know what the safety requirements would be to allow unmanned flight for civilian use of something like that.

Now, about the foam.. The area of a circle 2.5 miles in diameter is 547 million square feet (pi * r^2), so if you're going to cover just the surface (not trying to cover all branches on trees) to a depth of one foot, you need 547 million cubic feet of foam.

One Goodyear Blimp has 202,700 cubic feet of helium, so we'll assume it can hold that much foam.

So, fill a 707 with explosives and strap around it 2,700 Goodyear Blimps full of foam. Probably want to add some more, as some of the foam will be vaporized by the blast. Well, might be easier to just drop the blimp-sized bags of foam separately. There ya go, it's all designed. The rest is just engineering.

So, why doesn't it exist yet?

You are correct. According to aerospaceweb it first flew in 1964. At 42000, it could do 2110 mph and 650mph at sea level. The F-15 first flew in 1972 and can only do 1665 at 36000ft.

You are correct. According to aerospaceweb it first flew in 1964. At 42000, it could do 2110 mph and 650mph at sea level. The F-15 first flew in 1972 and can only do 1665 at 36000ft.

Another passenger aircraft which could do Mach 2+ was the Tupolev TU-144. Unfortunately following a crash at the Paris Air Show in 1973, the planes were taken out of service by 1978.