Problems with 6100 mph airliner

[Merad]

Aero Student here.

I could probably type out a laundry list of stuff here.

You missed the big one: air density. Subsonic airliners cruise at about 35000-40000 ft. The Concorde cruised at 50-60k ft. AFAIK they never "officially" released numbers for the SR-71 but it's speculated that its top speeds were reached at 110-120k ft or higher.

The atmosphere at sea level is almost 5x more dense than the atmosphere at 40k ft. Trying to run a vehicle at sea level means more drag, more heating, more fuel consumption, etc.

 

[NikolaeVarius]

You missed the big one: air density. Subsonic airliners cruise at about 35000-40000 ft. The Concorde cruised at 50-60k ft. AFAIK they never "officially" released numbers for the SR-71 but it's speculated that its top speeds were reached at 110-120k ft or higher.

The atmosphere at sea level is almost 5x more dense than the atmosphere at 40k ft. Trying to run a vehicle at sea level means more drag, more heating, more fuel consumption, etc.

Eh. That was sorta under my overall "mach number above 1 needs a host of special considerations"

 

[Leros]

And remember, it would be built by the lowest bidder.

I'm sure they take into account the cost of lawsuits if the plane were to malfunction when they choose the cheapest option.

 

[BUTCH1]

Any kind of equipment or control surface malfunction at that speed would yield horrific results. The development cost would be astronomical, resulting in a plane that's just not economically viable, so it takes a few hours to fly with the current planes, big deal, that's what tablets are for..

 

[Howard]

Aero Student here.

I could probably type out a laundry list of stuff here.

First on the train bit. Maglev is extremely power efficient. No high speed train in the world is going to go and use wheels. Sea level high speed trains are not economically feasible in the US because of lack of stuff to actually connect in the first place.

Supersonic flight isn't economical for several reasons.
1) Enormous fuel costs. Engines are only efficient in fairly narrow regions. Supersonic flight is a whole other ballpark in terms of engine efficiency. You need special fuels and such.
2) Complexity of design
3) Chances that if something goes wrong, something is REALLY going to go wrong
4) Going over mach 1 is an extremely big deal. Current planes go about mach .7-.8 at cruise.
5) I don't want to keep going on about this

Are you guys studying this?

http://www.meneren.com/projects/transportation/LIM.html

 

[ichy]

Based on the history of other supersonic aircraft, what challenges would this kind of craft face

Insane fuel consumption.

 

[ichy]

Air travel hasn't changed a heck of a lot since the Boeing 707 went into service 55 years ago. Air travel was still glamorous back then, unlike the unpleasant experience it is today. Nor has it gotten much cheaper.

That last bit is completely untrue.

 

[ichy]

No question that it's nowhere near as glamorous as it was back then, but there's no denying how much less expensive it is now.

If you're willing to pay the prices people paid back in the day you can fly first class nowadays, which on a good airline is still pretty damned glamorous (see Emirates, Singapore Airlines, Swiss, etc.)

 

[ichy]

as long as sonic booms are produced, commercial supersonic aircraft will not fly over land. if they can't fly over land, they can't make money. the concorde has already demonstrated how a vip-only transatlantic shuttle is a money loser.

Actually the Concorde made an operating profit on the routes that it ran. The problem is that there were so few routes where the Concorde was viable that they could never hope to sell enough to recoup development costs.