Hermeus supersonic airliner

[Shpaget]

https://www.hermeus.com/

These guys want to build a Mach 5+ airliner. They give no technical details about size, capacity, range or anything of substance apart from the Mach 5 number and their wish to do no "R", just "D" part of the "R&D".

Apparently they have received some venture capital and their plan is to have something flying in 10 years.

My take? A venture caputalist and his money are soon parted. The bad vibes I get from this are strong.

Edited May 26, 2019 by Shpaget

[Scotius]

Are their investors prepared to sink a lot... a LOT more money in R&D process? Because as history teaches us, building a hypersonic aircraft is not easy task. Nor cheap.

[wumpus]

There is a bit of slight of hand going on: they talk a lot about mach >5 but only show plans for mach 2.2.  Mach 2.2 is *possible*, but still probably involves at least a billion dollar NRE (possibly only hundreds of millions since they have SpaceX alumni used to doing things on the cheap).  Looks like a plan to scam VCs out of money, possibly to play "not so simple airplanes" in real life.

Going to mach ~5 would simply eat any possible profit (don't count on any) from the mach 2.2 plane and require amazing levels of both research and development.  I've been pushing the X-43 as a great example of this, but it has almost no payload and I have doubts about the range (room for all the hydrogen fuel it needs).  Also don't forget about the time needed to go to the airport (that can launch/land mach 5 aircraft) and from the airport you land at: if the customer isn't taking two helicopter flights already for an all-air flight you won't save any time with this ridiculous aircraft.  You probably won't find any customers for the mach 2.2 aircraft that aren't heavy helicopter users either.

[StrandedonEarth]

Yeah, sustained Mach 5.5 is impractical if not impossible for passenger flight due to the heating loads 

[Mikki]

Retirement funding at its finest.

[satnet]

I did a little digging and it looks like the founders are from Generation Orbit which worked on the X-60A, an air launched rocket for hypersonic research. Giving them the benefit of the doubt they may simply underestimate how hard it will be to take that experience and turn it into something that really can be used for passengers (my cynicism says, they probably have some idea). To be fair Boeing thought they could do the same thing (see the video), though they did at least think they could fly domestic flights when they started and they were only going for about mach 3.

 

[Shpaget]

So, the only plane that is comparable in speed with this is the SR-71, which has a total carying capacity of 2 crew and a few cameras. The rest of the plane are pretty much just engines and fuel tanks.

Going from that to an airliner is quite a step.

[ZooNamedGames]

On 5/14/2019 at 10:28 PM, satnet said:

I did a little digging and it looks like the founders are from Generation Orbit which worked on the X-60A, an air launched rocket for hypersonic research. Giving them the benefit of the doubt they may simply underestimate how hard it will be to take that experience and turn it into something that really can be used for passengers (my cynicism says, they probably have some idea). To be fair Boeing thought they could do the same thing (see the video), though they did at least think they could fly domestic flights when they started and they were only going for about mach 3.

 

What ironically killed the American super sonic jets was the swing wing. Just too big and too difficult to get working in the 60s.

[mikegarrison]

21 hours ago, ZooNamedGames said:

What ironically killed the American super sonic jets was the swing wing. Just too big and too difficult to get working in the 60s.

What killed all supersonic commercial airliners is fuel efficiency and rules against overland supersonic travel.

[ZooNamedGames]

3 hours ago, mikegarrison said:

What killed all supersonic commercial airliners is fuel efficiency and rules against overland supersonic travel.

Yes, but ultimately those were problems that came about after Concorde entered routine service and the technical challenges (swing wing, fuselage material, etc) behind the jets become too costly to surmount.

[mikegarrison]

45 minutes ago, ZooNamedGames said:

Yes, but ultimately those were problems that came about after Concorde entered routine service and the technical challenges (swing wing, fuselage material, etc) behind the jets become too costly to surmount.

No, you are missing that they are all related. The 2707 needed that swing wing and stuff because of the lousy fuel efficiency and need for trans-Pacific range. Trans-Atlantic-only wasn't going to work -- Concorde already was there. Flights over land were out. Stopping to refuel negated the speed advantage. Only trans-Pacific was a viable market. But to carry enough fuel to get trans-Pacific needed miracle tech. And any subsonic overland segment needs good subsonic aero, thus the swing wing.

And every time the industry has looked at supersonic transport again, the same things (fuel efficiency and overwater flight) keep preventing it, even though we have much better tech these days.

Now there is a push to build supersonic bizjets. They are hoping a) the bizjet buyers don't care how much fuel costs, and b) small airplanes make small booms, so maybe they can get permission to fly supersonic over land.

Edited May 17, 2019 by mikegarrison

[ZooNamedGames]

Just now, mikegarrison said:

No, you are missing that they are all related. The 2707 needed that swing wing and stuff because of the lousy fuel efficiency and need for trans-Pacific range. Trans-Atlantic-only wasn't going to work -- Concorde already was there. Flights over land were out. Stopping to refuel negated the speed advantage. Only trans-Pacific was a viable market. But to carry enough fuel to get trans-Pacific needed miracle tech.

the swing wing optimizes flight chararacteristics more so than it's efficiency. If they wanted to maximize efficiency alone, they would've used a delta wing as per the Concorde's design. But they opted to design a swing wing as that would allow them to get better handling at a wider range of speeds (subsonic/transonic through to supersonic).

Fuel efficiency was important, especially as a factor in range- but didn't truly crush supersonic aircraft until the fuel crisis of the 80s.

[mikegarrison]

1 minute ago, ZooNamedGames said:

Fuel efficiency was important, especially as a factor in range- but didn't truly crush supersonic aircraft until the fuel crisis of the 80s.

Sorry, but that's not true. Right from entry into service the fuel efficiency of the Concorde meant huge ticket prices compared to the 747, and the market immediately chose for value over time. And most of the interest in the Concorde disappeared as soon as it was not allowed to fly overland supersonic.

[RocketSquid]

At those speeds, wings aren't really necessary, and are actually something of a detriment. Instead, you'd use a waverider configuration, with lift generated by the shockwave. This concept is far from the most ambitious aircraft design, though. In the late eighties to early nineties the united states government (through NASA and the DoD) funded the development of a plane that was intended to fly at speeds up to mach 20. By virtue of its absurdly high max speed, it would also have been an SSTO. They never got to the prototype-of-a-test-vehicle phase: The X-30 was intended as a two-man test vehicle for the National Air and Space Plane, which would be a passenger plane. However, even the X-30 never got built, only some structural mockups that were never flown. 

Is a plane such as Hermeus is proposing possible? Certainly. Is it gonna be built by a startup? No.

[Mikenike]

Hey guys, it took many a year for the creators of the x51 Waverider to make a hypersonic little missile. Any thing that is larger will never, i repeat never be able to sustain even mach 3. Nothing short of 4 sr71 engines and an Sr71 type fuselage with a larger cross section and body could get mach 3.

Edited May 26, 2019 by Mikenike
Because

[SRB]

On 5/14/2019 at 9:57 AM, wumpus said:

There is a bit of slight of hand going on: they talk a lot about mach >5 but only show plans for mach 2.2.  Mach 2.2 is *possible*, but still probably involves at least a billion dollar NRE (possibly only hundreds of millions since they have SpaceX alumni used to doing things on the cheap).  Looks like a plan to scam VCs out of money, possibly to play "not so simple airplanes" in real life.

Going to mach ~5 would simply eat any possible profit (don't count on any) from the mach 2.2 plane and require amazing levels of both research and development.  I've been pushing the X-43 as a great example of this, but it has almost no payload and I have doubts about the range (room for all the hydrogen fuel it needs).  Also don't forget about the time needed to go to the airport (that can launch/land mach 5 aircraft) and from the airport you land at: if the customer isn't taking two helicopter flights already for an all-air flight you won't save any time with this ridiculous aircraft.  You probably won't find any customers for the mach 2.2 aircraft that aren't heavy helicopter users either.

Mach 2.2 will be Concorde performance matched.

On 5/15/2019 at 3:44 AM, Shpaget said:

So, the only plane that is comparable in speed with this is the SR-71, which has a total carying capacity of 2 crew and a few cameras. The rest of the plane are pretty much just engines and fuel tanks.

Going from that to an airliner is quite a step.

Sounds like KSP

[magnemoe]

On 5/17/2019 at 7:22 PM, mikegarrison said:

No, you are missing that they are all related. The 2707 needed that swing wing and stuff because of the lousy fuel efficiency and need for trans-Pacific range. Trans-Atlantic-only wasn't going to work -- Concorde already was there. Flights over land were out. Stopping to refuel negated the speed advantage. Only trans-Pacific was a viable market. But to carry enough fuel to get trans-Pacific needed miracle tech. And any subsonic overland segment needs good subsonic aero, thus the swing wing.

And every time the industry has looked at supersonic transport again, the same things (fuel efficiency and overwater flight) keep preventing it, even though we have much better tech these days.

Now there is a push to build supersonic bizjets. They are hoping a) the bizjet buyers don't care how much fuel costs, and b) small airplanes make small booms, so maybe they can get permission to fly supersonic over land.

Yes, first they have probably solved the boom issue, you can make an supersonic plane pretty much as silent as an noisy subsonic one. 
Second issue is that you are selling bad business class seats at first class prices for an fast crossing, however it has to be point to point or the short travel is a bit pointless. an charter is always P2P. 
For commercial you can also get an flat bed business class ticket with an night flight and the sleep time is negated, take an shower at airport. 
Some night trains and ships run at reduced speeds to give an night sleep, this save fuel and keep train in line with the freight trains

[Guest]

Actually, rules against overland supersonic flight came after it became apparent 2707 wasn't going to work. And they were intended to kill the Concorde, at which they succeeded, because its fuel efficiency woes were partially due to having to fly subsonic for much longer than it was originally supposed to. As for the swing wing, that was for the exact same reason Tu-144 had its deployable canards and Concorde had its byzantine fuel pumping scheme. It was all to attain desired supersonic performance with the plane still being able to land. Subsonic cruise performance was not a design consideration, that's more in the engines than the wings. Concorde's landing speed was just short of crazy and it came in ridiculously steep. Tu-144 was a little better thanks to the canards, though judging from pictures not by much. It's actually landing that makes supersonic flight so hard for manned aircraft. If you design an airframe to be exclusively optimized for supersonic flight regime, you'll just end up with a missile.

The sonic boom issue was blown out of proportion by the US propaganda seeking to justify their ban on supersonic flight. Tu-144 flew pretty much only on overland routes (there wasn't exactly a big market for either transatlantic nor transpacific flights in the USSR), and it doesn't seem like it caused any notable disturbance, even though it was much more noisy and unreliable than Concorde. Granted, Soviet standards for that were a little bit more lax, but military aircraft also can and do fly supersonic overland with no complaints.

Edited May 27, 2019 by Guest

[ZooNamedGames]

Another factor to supersonic aircraft is their economy. Which boils down to fuel and seats. Everyone else has hammered the former topic so I'll skip discussing it for now. Addressing the second factor, seats, is a matter of airline economy on it's own. Due to the vast variation on seat number, seat pricing, and seating arrangement, we've seen airlines operate with a wide verity of different structures. Ranging from luxary, to economy with budget airlines starting to emerge and take the market by storm. 

Supersonic airliners have two markets they can try to make profit from- the wealthy (ie the 1%) and the business man. Wealthy people are willing to buy a luxury seat, but as the novelty of supersonic flight once again fades, the luxuries provided on super sonic flights will need to improve to keep their edge on "luxury quality". Most airlines make the bulk of their profit from economy seating and not first/premium seating. Getting the most money by utilizing as much of the cabin space as possible. Supersonic airliners are still too costly to make a profit from the budget approach, but there's still one market that would be willing to buy seats on a supersonic airliner- especially in preference over standard airfare- the business goer. Business travelers often travel on the businesses budget (there are exceptions but I'm speaking in generalization). Shorter transit times between destinations results in less cash spent on renting out hotels, cars, etc. As well as ensuring that the traveler can spend more time working and less time unable to work as they fly. 

Also- to readdress the superboom issue- bare in mind that all designs currently aren't optimized at all for their sonic wave that they create. With better design, through aerodynamic shape and whatnot, this could be minimized. 

[Guest]

Again, Concorde's boom wasn't bad, neither was Tu-144's. You don't need fancy optimization tricks. Sonic boom being a problem is a myth, one very deliberately created, to boot. Notice that neither Europe nor Asia had any restrictions like the US. Better to optimize for fuel consumption in supercruise. Tu-144 could have made it if Soviets took the project seriously instead of basing it entirely around one-upping the Concorde.

Concorde's seating was a bit cramped, not helped by the fact that it had to be long and narrow, but back then, even business class seats weren't quite as luxurious as ones on modern airliners. This problem could probably be solved by just making the thing larger. Generally, large planes are more economical than small ones. They are also harder to build, but we have better materials and manufacturing techniques. Concorde wasn't actually that big as far as airliners go, it was about 10m longer (most of it being the pointy nose) than a 757-300, while being much narrower.

[mikegarrison]

5 hours ago, magnemoe said:

Yes, first they have probably solved the boom issue, you can make an supersonic plane pretty much as silent as an noisy subsonic one.

What makes you think that?

There has been work on boom minimization, but I am told by an expert in the field that most of it relies on the airplane being relatively small. This is why some of the new bizjet concepts assume they will be able to lower their boom signature to acceptable levels, but nobody is claiming this for large airplanes (737/A320 size or bigger).

3 hours ago, Dragon01 said:

Tu-144 flew pretty much only on overland routes (there wasn't exactly a big market for either transatlantic nor transpacific flights in the USSR), and it doesn't seem like it caused any notable disturbance.

First of all, in the USSR it didn't matter whether the people complained about the boom or not. The government didn't care. Secondly, Russia has a LOT of nearly empty land. This is why they are fine with launching rockets over land, for instance, while most countries insist rocket launches should be over water. Thirdly, there was only one scheduled route the TU-144 was ever used on, and it only flew that route one day per week.

3 hours ago, Dragon01 said:

military aircraft also can and do fly supersonic overland with no complaints.

This is not true. Military airplanes are usually prohibited from flying supersonic over land except in designated military airspace or in exceptional cases.

And there are plenty of complaints about noise from military airplanes even when they fly subsonic.

[mikegarrison]

2 hours ago, ZooNamedGames said:

Most airlines make the bulk of their profit from economy seating and not first/premium seating.

This is not true as a general rule. It depends on the airline business model. LCCs (low cost carriers) tend to fly all coach and make their money on passenger volume. But many international carriers actually rely on business class as their main source of profit, which is why (for instance) that some A380s have an entire deck dedicated only to business class.

1 hour ago, Dragon01 said:

Notice that neither Europe nor Asia had any restrictions like the US.

I don't know where you are getting your incorrect information, but Europe and Asia definitely did (and do) have restrictions against supersonic flight over land. One of the main killers of the Concorde was when flights from Europe to Asia were all scrubbed because the countries being overflown refused to allow supersonic flight in their airspace. That's why all the regular Concorde routes ended up being trans-Atlantic.

Edited May 27, 2019 by mikegarrison

[kerbiloid]

skype + maglev = no hypersonic airlines

[ZooNamedGames]

1 hour ago, mikegarrison said:

This is not true as a general rule. It depends on the airline business model. LCCs (low cost carriers) tend to fly all coach and make their money on passenger volume. But many international carriers actually rely on business class as their main source of profit, which is why (for instance) that some A380s have an entire deck dedicated only to business class.

Which is what I meant.

[ZooNamedGames]

I was inferring that passenger volume was the profit- not the pricetag on a seat.