USAF/US NAVY 6th Generation Fighter Programs - F/A-XX, F-X, NGAD, PCA, ASFS news

[dark sidius]

That's also probably the reason why the USAF is pushing so hard for the adaptive cycle engine, as that unlocks that ability from the start.

And it seem to be in a good way , for what we read the XA-100 seem to work well, now all is in the political decision, the US company are ready to build the NGAD so now the new administration must take their responsibility If Republican speak about America great again time to prove it with the budget to build the edge of the technology.

 

[Jason Dykstra (Wyvern)]

Agreed, once the airforce refines the requirements for the NGAD (which may have already happened), it will be a political decision.

 

[Josh_TN]

I think IR detection technology is a bit overrated at the moment, but it's worth noting you made detection a lot more likely at those speeds. There has to be a pretty good reason to burn that much gas, afterburner or no.

For either NGAD or the Boxer/J-36, their moment will be end of decade (probably later for NGAD). The U.S. at least will have an orbital network of missile tracking satellites in multiple orbital altitudes with the LEO segment entering its third iteration. The PRC is presumably not far behind. These aircraft obviously are not at the speeds and altitudes of the hypersonic weapons that this network is intended to track, but they are a lot larger. The U.S. is also quite clearly experimenting with small inexpensive networked UAVs with IR, not just CCA sized aircraft but also more attritable platforms like air launched UTAP-22 (likely just surrogate but likely representative in size/scale of future NGAD components). I think supercruise at Mach 1.5 - 2 is likely the upper practical limit for both reasons of fuel consumption and IR detection.

 

[Kat Tsun]

That's also probably the reason why the USAF is pushing so hard for the adaptive cycle engine, as that unlocks that ability from the start.

I think they just want to get away from Pratt tbf.

 

[Airbus A340]

There is a study of high speed bombers from the 1990's or early 2000's. There is a longer version but I did not find it. This is the short version. The thing to keep in mind here is that the entire system needs to be optimized, not 1 parameter. RAND looked at building a supersonic bomber not to be more survivable in the air, but to make the air bases more survivable by keeping them in CONUS.

1. The bombers still need RCS reduction to be survivable (obvious).
2. The bombers cannot be low IR emissions. Not a problem then, a huge problem now.
3. The bombers deliver low cost shorter range munitions.
4. The bombers need F-22 and tanker support.
5. The bombers are more efficient than subsonic bombers because they complete more sorties per unit time.
6. The study seems to ignore the entire history of supersonic flight, ie that whenever an air force or an airline has a choice, they choose subsonic. It can be said that USAF moved back to subsonic to increase bomber survivability (low altitude) but the airlines never went supersonic. In the end, the bomber is a delivery system. A study that trades off R&D cost, production cost, operating cost, munitions delivery per unit time, survivability, and the types of munitions that can be delivered due to that level of survivability has, to my knowledge, not been released. No RAND or CNA study that I have seen looks at this issue. It is germane to the issue we are discussing here though. A further complication is the fact that capabilities can be offloaded to other platforms much more easily than when the RAND study appeared. I suspect that the complexity of this study is why NGAD has been paused. I suspect that a technological development occurred that caused the USAF to redo the study of the type described here, a study they must have performed. The results of this study will not be available to us although we will see the results in NGAD. A further complication is that NGAD has to have A2A capability, a capability ignored in the RAND study. I think the sheer difficulty of developing a model, then crunching numbers while factoring in tech changed over the life of NGAD that will need to be accommodated in the program makes this vastly more complex than anything we have ever seen before.

The study below is a good start to see why speed is a good idea though.

RAND Supersonic Bomber Study

 

[Josh_TN]

It’s worth noting that there were a rather small number of supersonic bombers that actually entered service, and almost all were only briefly supersonic on afterburner (Tu22, Tu-22M, Tu-160, F-111, B-1B marginally). The only exception I can think of is the B-58.

 

[Airbus A340]

The RAND study called for a flight profile that was supersonic except for takeoff, climb, descent, and aerial refueling. When I read the study, it just screamed "unrealistic".

 

[dark sidius]

There is a study of high speed bombers from the 1990's or early 2000's. There is a longer version but I did not find it. This is the short version. The thing to keep in mind here is that the entire system needs to be optimized, not 1 parameter. RAND looked at building a supersonic bomber not to be more survivable in the air, but to make the air bases more survivable by keeping them in CONUS.

1. The bombers still need RCS reduction to be survivable (obvious).
2. The bombers cannot be low IR emissions. Not a problem then, a huge problem now.
3. The bombers deliver low cost shorter range munitions.
4. The bombers need F-22 and tanker support.
5. The bombers are more efficient than subsonic bombers because they complete more sorties per unit time.
6. The study seems to ignore the entire history of supersonic flight, ie that whenever an air force or an airline has a choice, they choose subsonic. It can be said that USAF moved back to subsonic to increase bomber survivability (low altitude) but the airlines never went supersonic. In the end, the bomber is a delivery system. A study that trades off R&D cost, production cost, operating cost, munitions delivery per unit time, survivability, and the types of munitions that can be delivered due to that level of survivability has, to my knowledge, not been released. No RAND or CNA study that I have seen looks at this issue. It is germane to the issue we are discussing here though. A further complication is the fact that capabilities can be offloaded to other platforms much more easily than when the RAND study appeared. I suspect that the complexity of this study is why NGAD has been paused. I suspect that a technological development occurred that caused the USAF to redo the study of the type described here, a study they must have performed. The results of this study will not be available to us although we will see the results in NGAD. A further complication is that NGAD has to have A2A capability, a capability ignored in the RAND study. I think the sheer difficulty of developing a model, then crunching numbers while factoring in tech changed over the life of NGAD that will need to be accommodated in the program makes this vastly more complex than anything we have ever seen before.

The study below is a good start to see why speed is a good idea though.

RAND Supersonic Bomber Study

I don't understand the link between a supersonic bomber study and the NGAD ? Lockheed built a supersonic cruiser with the F-22 , I don't see why it could be more complicated for the NGAD.

 

[Josh_TN]

I think the post was a response to contentions that an aircraft could be optimized for higher speeds given an optimized airframe for said speed. You can supercruise, but the faster you go, the steeper the cost in other speed ranges, and historically very few operational aircraft flew that way (SR-71 and?).

 

[Josh_TN]

It’s worth noting that there were a rather small number of supersonic bombers that actually entered service, and almost all were only briefly supersonic on afterburner (Tu22, Tu-22M, Tu-160, F-111, B-1B marginally). The only exception I can think of is the B-58.

One thing I did not think of when first posting this is that almost all of the examples are variable geometry on top.

 

[NMaude]

I wonder if the B-1A could super cruise as it was a Mach-2 design.

 

[_Del_]

I wonder if the B-1A could super cruise as it was a Mach-2 design.

Not a great engine candidate for supercruise. There are a lot of Mach 2 designs. Almost none of them supercruise.

 

[quellish]

In the early 2000s NASA was doing work on efficient supersonic cruise. While NASA did focus on civil applications DoD did certainly participate and benefit from this research. Some of the research could clearly be applied to NGAD.

 

[Scott Kenny]

There is a study of high speed bombers from the 1990's or early 2000's. There is a longer version but I did not find it. This is the short version. The thing to keep in mind here is that the entire system needs to be optimized, not 1 parameter. RAND looked at building a supersonic bomber not to be more survivable in the air, but to make the air bases more survivable by keeping them in CONUS.

1. The bombers still need RCS reduction to be survivable (obvious).
2. The bombers cannot be low IR emissions. Not a problem then, a huge problem now.
3. The bombers deliver low cost shorter range munitions.
4. The bombers need F-22 and tanker support.
5. The bombers are more efficient than subsonic bombers because they complete more sorties per unit time.
6. The study seems to ignore the entire history of supersonic flight, ie that whenever an air force or an airline has a choice, they choose subsonic. It can be said that USAF moved back to subsonic to increase bomber survivability (low altitude) but the airlines never went supersonic. In the end, the bomber is a delivery system. A study that trades off R&D cost, production cost, operating cost, munitions delivery per unit time, survivability, and the types of munitions that can be delivered due to that level of survivability has, to my knowledge, not been released. No RAND or CNA study that I have seen looks at this issue. It is germane to the issue we are discussing here though. A further complication is the fact that capabilities can be offloaded to other platforms much more easily than when the RAND study appeared. I suspect that the complexity of this study is why NGAD has been paused. I suspect that a technological development occurred that caused the USAF to redo the study of the type described here, a study they must have performed. The results of this study will not be available to us although we will see the results in NGAD. A further complication is that NGAD has to have A2A capability, a capability ignored in the RAND study. I think the sheer difficulty of developing a model, then crunching numbers while factoring in tech changed over the life of NGAD that will need to be accommodated in the program makes this vastly more complex than anything we have ever seen before.

The study below is a good start to see why speed is a good idea though.

RAND Supersonic Bomber Study

There was a civilian-side comparison done: 2707 versus 707 and 747, for a flight from eastern US to London or Paris.

Cost is a bit higher, about twice that of the slower planes due to fuel burn, but you get ~3x as many trips at Mach 2.7.

The RAND study called for a flight profile that was supersonic except for takeoff, climb, descent, and aerial refueling. When I read the study, it just screamed "unrealistic".

Funny, that's basically the same flight profile as the Blackbird.

Not so unrealistic.

 

[dark sidius]

There was a civilian-side comparison done: 2707 versus 707 and 747, for a flight from eastern US to London or Paris.

Cost is a bit higher, about twice that of the slower planes due to fuel burn, but you get ~3x as many trips at Mach 2.7.




Funny, that's basically the same flight profile as the Blackbird.

Not so unrealistic.

Reuse the SR-71 engine concept with today technology, for less fuel burning with the same speed.

 

[SK2]

Not only the SR-71, but also the MiG-25 (and maybe MiG-31 also?)
Civilian side, Concorde, apart from unable to air refuel, has exactly the same flight profile.

 

[NeilChapman]

Don't know that I'd want to put all my eggs in one basket. All it takes is the datalink being jammed, or otherwise compromised, and that's that.

I guess they better get to work on improving that data link.

Has anybody been talking about at what altitude these cca's will be operating?

 

[quellish]

Don't know that I'd want to put all my eggs in one basket. All it takes is the datalink being jammed, or otherwise compromised, and that's that.

Collaborative Operations in Denied Environment, other programs. They have been working on it for a long time.

 

[Scott Kenny]

Reuse the SR-71 engine concept with today technology, for less fuel burning with the same speed.

Ironically, we probably would be best served with a turbojet or extremely low bypass turbofan for M3 cruise at 80+kft.

 

[Josh_TN]

Collaborative Operations in Denied Environment, other programs. They have been working on it for a long time.

Incr1 is geared to work with F-35, so I would expect similar cruise altitude. Other increments will vary.