Airbus Mach 4.5 Hypersonic Jet. Heathrow to NYC in 1 hour

[Humbug]

Remember the Concords. They could do speeds like this back in the 90s. Ok maybe only Mach 1.4 but still very fast but too expensive to keep running

It wasn't mach 1.4 in the 90s.

It was commercial flights at mach 2 in the 70s! The first test flight was 1969. Staggeringly impressive.

[dalekphalm]

Remember the Concords. They could do speeds like this back in the 90s. Ok maybe only Mach 1.4 but still very fast but too expensive to keep running

There were numerous reasons why the Concorde was retired and no Hypersonic Jet was ever introduced after that.

 

The biggest was Public Perception. The general publc saw the Concorde as:

1. Too expensive - only for the rich

2. Noise Pollution - it was very loud unless the Pilots remembered to throttle way down near residential areas

3. Very expensive to operate - Fuel was particularly expensive for this beast, and it chugged it.*

4. Safety - despite being relatively safe with an experienced pilot, it had some very high profile crashes - and it was a notoriously difficult plane to learn to fly.

 

*As an example, the Concorde achieved 15.8 Passenger Miles per Gallon (pm/g). A Boeing 747 achieves 46.4 pm/g. That means that the 747 is three times as efficient as the Concorde, because it can take so many more passengers.

https://en.wikipedia.org/wiki/Concorde#Testing

 

Decades... If ever. Noise pollution is a big deal in most areas now and this plane has no dampening that I could see/find.

[MonkeyFace]

Paris to Tokyo in 3 hours...sign me up!

[ManWithBeard1990]

I was referring to the fusion-fission jet that Boeing has recently patented, but clearly unfeasible at this time.

When you have fission in your engine anyway, why bother with fusion? It's a dirty factory of nuclear waste anyway. If you want to go fusion, go all the way. 

Besides, you can get there with internal combustion. Not easily, but it's way more practical than Boeing's silly proposition.

 

I thought that they couldn't even take fighter jets over mach 3. Something about the pressure the flight suits would have to create would break bones. Or was there a different reason for that?

They can't and there is a reason, but it's not the flightsuits. Those are the reason you can't really go over a certain amount of G, but I can't remember how much. about 10, or somewhere near that order of magnitude. The reason you can't go too fast is the fact that the skin of the aircraft gets exposed to high temperatures as air heats up when it's compressed in the shockwave. Friction is also a factor. Concorde's skin heated up past 100°C in flight, and it can't go any faster than it did because the material loses too much of its strength with higher temperatures. For higher speeds, the Blackbird's skin for example is made from titanium, which is resistant to high temperatures. The XB-70's skin consisted of stainless steel, and so did the skin of the MiG 25. You want to go faster than that, you'll need active cooling. How though, you might wonder, as there is nowhere you can put a radiator that isn't going to be exposed to high temperatures as well. Test planes for hypersonic flight typically have a skin cooled by the fuel that powers them. Often, liquid hydrogen is used because it's very lightweight, and very, very cold. It's a nice concept: The more fuel you use, the more cooling you get, the faster you go. 

There were numerous reasons why the Concorde was retired and no Hypersonic Jet was ever introduced after that.

 

The biggest was Public Perception. The general publc saw the Concorde as:

1. Too expensive - only for the rich

2. Noise Pollution - it was very loud unless the Pilots remembered to throttle way down near residential areas

3. Very expensive to operate - Fuel was particularly expensive for this beast, and it chugged it.*

4. Safety - despite being relatively safe with an experienced pilot, it had some very high profile crashes - and it was a notoriously difficult plane to learn to fly.

 

*As an example, the Concorde achieved 15.8 Passenger Miles per Gallon (pm/g). A Boeing 747 achieves 46.4 pm/g. That means that the 747 is three times as efficient as the Concorde, because it can take so many more passengers.

https://en.wikipedia.org/wiki/Concorde#Testing

If Concorde was as big as the 747, not to mention packed the passengers in more efficiently (remember this was a luxurious airplane) its efficiency per passenger would be way better than it was, rivaling and perhaps surpassing the jumbojet, at least when paired with engines not designed in the 1960's. Just like today's jet planes are a bit more efficient than the propeller powered aircraft of days gone by because the higher speeds allow flight at greater altitude, and therefore less air pressure and so less drag, supersonic flight can be better than what's available today. You should not compare Concorde to 747.

[dalekphalm]

When you have fission in your engine anyway, why bother with fusion? It's a dirty factory of nuclear waste anyway. If you want to go fusion, go all the way. 

Besides, you can get there with internal combustion. Not easily, but it's way more practical than Boeing's silly proposition.

 

They can't and there is a reason, but it's not the flightsuits. Those are the reason you can't really go over a certain amount of G, but I can't remember how much. about 10, or somewhere near that order of magnitude. The reason you can't go too fast is the fact that the skin of the aircraft gets exposed to high temperatures as air heats up when it's compressed in the shockwave. Friction is also a factor. Concorde's skin heated up past 100°C in flight, and it can't go any faster than it did because the material loses too much of its strength with higher temperatures. For higher speeds, the Blackbird's skin for example is made from titanium, which is resistant to high temperatures. The XB-70's skin consisted of stainless steel, and so did the skin of the MiG 25. You want to go faster than that, you'll need active cooling. How though, you might wonder, as there is nowhere you can put a radiator that isn't going to be exposed to high temperatures as well. Test planes for hypersonic flight typically have a skin cooled by the fuel that powers them. Often, liquid hydrogen is used because it's very lightweight, and very, very cold. It's a nice concept: The more fuel you use, the more cooling you get, the faster you go. 

If Concorde was as big as the 747, not to mention packed the passengers in more efficiently (remember this was a luxurious airplane) its efficiency per passenger would be way better than it was, rivaling and perhaps surpassing the jumbojet, at least when paired with engines not designed in the 1960's. Just like today's jet planes are a bit more efficient than the propeller powered aircraft of days gone by because the higher speeds allow flight at greater altitude, and therefore less air pressure and so less drag, supersonic flight can be better than what's available today. You should not compare Concorde to 747.

Yes but that's a huge hypothetical.

 

You might as well say "If the Concorde wasn't actually the Concorde, but was something totally different instead..."

 

We have no way of knowing that it is even technically feasible to increase the size of the Concorde and by extension the passenger capacity.

 

We should compare the Concorde to a 747, because one of the complaints of it, and reasons for shutting down the program, was poor fuel efficiency. That makes it a fair comparison.

 

Yes, it's faster, but less fuel efficient for the whole trip.

 

Does that mean fuel efficiency is more important than trip time? No. But it's still an important consideration.

[Rekx]

when i saw the headline it reminded me of top gun 

 

[Revinval]

So supersonic fluid dynamics don't allow for supersonic aircraft to be even close to subsonic in terms of fuel efficiency.

[ManWithBeard1990]

Yes but that's a huge hypothetical.

 

You might as well say "If the Concorde wasn't actually the Concorde, but was something totally different instead..."

 

We have no way of knowing that it is even technically feasible to increase the size of the Concorde and by extension the passenger capacity.

 

We should compare the Concorde to a 747, because one of the complaints of it, and reasons for shutting down the program, was poor fuel efficiency. That makes it a fair comparison.

 

Yes, it's faster, but less fuel efficient for the whole trip.

 

Does that mean fuel efficiency is more important than trip time? No. But it's still an important consideration.

A man can dream, can't he?

Sure it's feasible.

The real question is, is it a good idea. The answer is not really but someone should try just because it's awesome.

[TheSLSAMG]

There was accidents and the sonic boom.. that caused its discontinuation

The Concorde had one accident. And given time, technology could have evolved to lessen any issues.

[Dabombinable]

The Concorde had one accident. And given time, technology could have evolved to lessen any issues.

It was actually more than 1, but the main accident was caused by a piece of metal falling out of the engine of a Continental jet that had used the runway previously, which caused the tyres to burst (they were a bit delicate when the aircraft was approaching take off speed-and part of the landing gear which helped keep the aircraft straight during take off wasn't installed), which flung rubber into the landing gear, damaging it badly, flung rubber at the wing which caused the re-fueling cap in front of the engine, which caused fuel to be sucked straight into the engine, causing a fire which eventually caused the control surfaces on the left wing to fuse, which means that the pilot lost control. The fragility of the fuel tanks was fixed but it was too late for the Concorde.

[dalekphalm]

A man can dream, can't he?

Sure it's feasible.

The real question is, is it a good idea. The answer is not really but someone should try just because it's awesome.

It certainly would be very cool to see more Hypersonic aircraft enter into operation in the commercial sector. But we shall see if that's a pipe dream or not. I suspect that we'll need to wait for some bigger revolutions in propulsion technology.

 

The Concorde had one accident. And given time, technology could have evolved to lessen any issues.

Indeed. The biggest killer was public perception. The general public lost faith in the vehicle after the major crash - and that was pretty much the end after that. Any issues were magnified ten-fold in the public eye because of it. Noise pollution and fuel efficiency, while somewhat bad, were made to seem much worse.

[ManWithBeard1990]

It certainly would be very cool to see more Hypersonic aircraft enter into operation in the commercial sector. But we shall see if that's a pipe dream or not. I suspect that we'll need to wait for some bigger revolutions in propulsion technology.

True, true. But it's not as if we're talking about technology that has never been tried before, just on a much bigger scale.