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

[bring_it_on]

Many years to go before we see a full fledged FX in development. FA_XX for the USN is required a bit earlier, but that does not have to be a full fledged 6th gen fighter in 6th gen timeframes. I think the Navy will go for a conservative, twin 5.5 gen type of aircraft with avionics and sensor commonality with the F-35C. This is if the Lockheed submitted Super Lightning proposal is not accepted as a low cost low risk solution. Boeing however has a very strong lobby within the USN and the congress, and I am not sure the congress will be comfortable with the fact that only Lockheed gets fighter work post the super hornet and the Strike eagle.

 

[sferrin]

Many years to go before we see a full fledged FX in development. FA_XX for the USN is required a bit earlier, but that does not have to be a full fledged 6th gen fighter in 6th gen timeframes. I think the Navy will go for a conservative, twin 5.5 gen type of aircraft with avionics and sensor commonality with the F-35C. This is if the Lockheed submitted Super Lightning proposal is not accepted as a low cost low risk solution. Boeing however has a very strong lobby within the USN and the congress, and I am not sure the congress will be comfortable with the fact that only Lockheed gets fighter work post the super hornet and the Strike eagle.

I could see something ending up looking somewhat similar to a J-20. DSI inlets, canard-delta (unless they could get a pure delta to work. . .maybe by using TVC), twin F135. No ventral fins. As for Boeing, unless that can come up with a compelling design, and demonstrate the ability to produce a low RCS aircraft, I don't know why they'd even be considered. Northrop Grumman on the other hand. . .

 

[Rhinocrates]

It looks like simple geometry will cause the design and schedules for the F-X and F/A-XX to diverge. Both the Boeing and Lockheed concepts for F-X that we've seen show very large - and long - aircraft that I can't imagine fitting on Nimitz/Ford class carrier elevators - consider how different Northrop's AF and naval versions for ATF differed with length restrictions determining the canard and odd sawtooth tails. It would seem very likely then that the F/A-XX would come first and to be very different from the later F-X.

 

[sferrin]

It looks like simple geometry will cause the design and schedules for the F-X and F/A-XX to diverge. Both the Boeing and Lockheed concepts for F-X that we've seen show very large - and long - aircraft that I can't imagine fitting on Nimitz/Ford class carrier elevators - consider how different Northrop's AF and naval versions for ATF differed with length restrictions determining the canard and odd sawtooth tails. It would seem very likely then that the F/A-XX would come first and to be very different from the later F-X.

Both the A-3 Skywarrior and A-5 Vigilante were about 76-1/2' (the Tomcat was only about 63') so there is room for growth (though IIRC there's still an 84,000lb limit to the catapults).

 

[bobbymike]

It looks like simple geometry will cause the design and schedules for the F-X and F/A-XX to diverge. Both the Boeing and Lockheed concepts for F-X that we've seen show very large - and long - aircraft that I can't imagine fitting on Nimitz/Ford class carrier elevators - consider how different Northrop's AF and naval versions for ATF differed with length restrictions determining the canard and odd sawtooth tails. It would seem very likely then that the F/A-XX would come first and to be very different from the later F-X.

Both the A-3 Skywarrior and A-5 Vigilante were about 76-1/2' (the Tomcat was only about 63') so there is room for growth (though IIRC there's still an 84,000lb limit to the catapults).

How maneuverable can a tailess platform be with thrust vectoring? Could you have an X-44 'type' configuration on a carrier?

 

[Sundog]

How maneuverable can a tailess platform be with thrust vectoring? Could you have an X-44 'type' configuration on a carrier?

Based on the X-31 research I would say it could be as maneuverable as you want it to be. But that, I don't think would be the question that needs answering. I think it would come down to how much excess thrust capability you would need to meet the maneuvering requirement, so as usual with aircraft design, it would come down to the trade off between the thrust requirement and the maneuverability requirement in terms of engine sizing with regards to packaging/weight and fuel mass.

 

[bring_it_on]

Are there any programs to advance other TV solutions besides the moving nozzle or paddle type we have seen on test aircraft or production representative fighters such as the f-22? I remember years back they played around with fluidic tvc. Any advances?

http://www.geocities.ws/m_mason007/Paper.pdf

 

[Mat Parry]

http://aviationweek.com/awin/broadband-stealth-may-drive-taranis-design


"The one-piece elevons cannot provide yaw input that is independent of pitch or roll. There is no visible source of yaw control, which points to the use of thrust vectoring.

In 2010, BAE teamed with two British universities to build a small UAV called Demon with fluidic vectoring—using air injection inside the exhaust to vector the thrust, with no moving parts externally or in the exhaust stream—as part of a flight-control system with no moving surfaces. A Rolls-Royce patent filed in the U.K. in 2005 outlines a fluidic vectoring system designed to generate yawing moments in a high-aspect-ratio 2-D nozzle."

 

[bring_it_on]

Computational Study of an Axisymmetric Dual Throat Fluidic Thrust Vectoring Nozzle for a Supersonic Aircraft Application - NASA Langley Research Center

A computational investigation of an axisymmetric Dual Throat Nozzle concept has been conducted. This fluidic thrust-vectoring nozzle was designed with a recessed cavity to enhance the throat shifting technique for improved thrust vectoring. The structured-grid, unsteady Reynolds- Averaged Navier-Stokes flow solver PAB3D was used to guide the nozzle design and analyze performance. Nozzle design variables included extent of circumferential injection, cavity divergence angle, cavity length, and cavity convergence angle. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 1.89 to 10, with the fluidic injection flow rate equal to zero and up to 4 percent of the primary flow rate. The effect of a variable expansion ratio on nozzle performance over a range of freestream Mach numbers up to 2 was investigated. Results indicated that a 60° circumferential injection was a good compromise between large thrust vector angles and efficient internal nozzle performance. A cavity divergence angle greater than 10° was detrimental to thrust vector angle. Shortening the cavity length improved internal nozzle performance with a small penalty to thrust vector angle. Contrary to expectations, a variable expansion ratio did not improve thrust efficiency at the flight conditions investigated.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070031765.pdf

 

[RadicalDisconnect]

Speaking of AETD, can anyone with access summarize the full article here?

http://www.janes.com/article/38207/pratt-continues-aetd-design-work-preps-for-2016-testing

 

[marauder2048]

Both the A-3 Skywarrior and A-5 Vigilante were about 76-1/2' (the Tomcat was only about 63') so there is room for growth (though IIRC there's still an 84,000lb limit to the catapults).

I thought I recall reading that the EMALS limit was approximately 100,000 lbs.

 

[bring_it_on]

Speaking of AETD, can anyone with access summarize the full article here?

http://www.janes.com/article/38207/pratt-continues-aetd-design-work-preps-for-2016-testing

Don't have the full article but apparently a brand new adaptive fan design was tested sometime last year, a full core rig test is scheduled for 2015 with a full engine test following a year after that. P&W is of course just 1/2 of the AETD with GE working on the other and they have had the opportunity to work on the DOD funded ADVENT program (where P&W was absent) for a few years prior to joining the AETD program

General Electric (GE) says it completed engine core testing for its ADaptive Versatile ENgine Technology (ADVENT) demonstrator earlier this month on 6 February. The prototype variable-cycle engine reached the "highest combination of compressor and turbine temperatures ever recorded in aviation history", says the company, which is working on the programme for the US Air Force Research Laboratory (AFRL).

GE says that the ADVENT effort will wrap-up later this year with a full engine test. However, the technologies developed through the programme will be used on the AFRL's the follow-on Adaptive Engine Technology Demonstrator (AETD) development.

This is a critical milestone that gives us great confidence as we prepare for the full engine test in ADVENT later this year and move forward on the design of the AETD engine," says Dan McCormick, GE's general manager for the ADVENT and follow-on AETD programmes. "We'll integrate these proven ADVENT technologies into our AETD engine, along with advanced controls and exhaust system designs."

GE attributes the accomplishment to advanced lightweight, heat-resistant ceramic matrix composite (CMC) materials, which combined with an adaptive low pressure spool, result in a 25% improvement in fuel efficiency, a 30% increase in operating range and a 5% to 10% improvement in thrust compared to existing fixed-cycle engines.

GE says it completed the initial design review for its version of the AETD engine on 8 February. A preliminary design review milestone is scheduled for November 2014. The AETD programme will conclude in 2016 following fan rig testing and a core engine test.

Pratt & Whitney is developing a rival engine for the AETD programme, having displaced Rolls & Royce, which was developing a competing ADVENT engine.

http://www.flightglobal.com/news/articles/general-electric-completes-advent-core-testing-382542/

http://www.airforce-technology.com/news/newspratt-whitneys-aetd-programme-engine-passes-initial-design-review

The more interesting aspect is about what will happen once the AETD concludes. Sequestration should end by that time (hopefully) giving the services more flexibility. 2016 is also the time the US navy expects to conclude it Analysis of Alternatives on the Fa-XX program. I am also interesting in knowing what advantages can Pratt bring back to the F-135 program given they have selected the F-135 as the baseline for the AETD.

http://www.defensenews.com/article/20140224/DEFREG02/302240033/Pentagon-Air-Force-Double-Down-Engine-Technology

 

[bobbymike]

Pratt Eyes Next-Gen Fighter Motor

Hartford, Conn.—The Pentagon’s new engine initiative—a $1 billion effort slated to start in Fiscal 2015—seems to be aimed at enabling the next Air Force fighter, Pratt & Whitney next-generation engine chief James Kenyon said. “That’s certainly what we’re seeing,” he told Air Force Magazine during a company media event. However, “they’re not real clear what that’s going to be.” He noted that the budget request includes $20 million for “next generation air dominance,” and he suspects it will be used for “studies, analyses of alternatives, requirements studies, [and] trying to determine exactly what the requirements are going to look like.” The trade studies will likely examine “how critical is supercruise? Just how far do I want my range to be? Is it 600 nautical miles … 800 … 1200?” Also to be resolved are issues like manned versus unmanned, how many capabilities will be onboard versus offboard, etc. “The key buzzword is ‘system of systems,’” he observed. All of these answers will “come to define the primary platform, the fighter platform … and that will define what the propulsional problems will be.”
—John A. Tirpak
5/27/2014

 

[Triton]

My apologies if we already discussed this, but does anyone care to speculate concerning the range of the high-powered solid state laser (SSL) for F-X or F/A-XX for it to be a practical ground attack weapon? Or the range of the moderate-power laser which would presumably eliminate incoming missiles?

“Laser and beam control systems are being investigated independent of platform in the flight regime from altitudes Sea Level to [65,000ft] and speeds from Mach 0.6 to 2.5,” the AFRL posting states.

The USAF is interested in three categories of lasers. These include low-power lasers for illuminating, tracking, targeting, and denying/defeating enemy sensors. The AFRL is also interested in moderate-power laser protective weapons system, which would presumably eliminate incoming missiles and high-powered lasers for offensive operations against other aircraft or ground targets.

Source:
http://news.usni.org/2013/11/20/air-force-seeks-laser-weapons-next-generation-fighters

 

[AeroFranz]

Damaging sensors on a non-hardened missile's nose is probably not too hard. DIRCMs work at pretty low power (although to be fair they blind more than damage IR seekers - a fast approaching AAM is a very different beast).
I have read numbers in the 100's of kW of Laser power being floated as tactically relevant. Given the conversion efficiency of lasers, you probably need to provide five to six times as much shaft horsepower from your powerplant to get to that power level. I am not familiar with accessory pads on tactical fighters, but they extract nowhere near that power. Hence the musings about using the F-35 replacing the lift fan with a laser.

 

[Triton]

Thank you, Aerofranz.

 

[bobbymike]

Next Generation Air Dominance

The Pentagon is more than a year into an analysis of how it will maintain air dominance in the mid 21st century, said Pentagon acquisition chief Frank Kendall. He told reporters on June 12 he put DARPA to work on the "air dominance initiative" in early 2013. DARPA is tasked with determining if future air dominance will be in the form of an aircraft, or “more likely a system-of-systems approach with an aircraft plus" electronic warfare, sensors, and so on, "and how they're networked together," he said. The ultimate solution "is certainly going to be building on” the capabilities of the F-35 strike fighter, which is designed to accommodate upgrades, he said. Kendall said he's grateful that Capitol Hill have allowed the Pentagon to start to "do some follow-on development” for the F-35. “We need to start thinking now about the requirements for the next blocks of software," said Kendall.​​
—John A. Tirpak
6/18/2014

 

[dark sidius]

I ask myself how they can transform the F-35 in a air dominant fighter, with mach 1.6 top speed and not realy high maneuvrable ? it need more than a upgrade, surely another plane.

 

[Dragon029]

Top speed can be increased with further engine revisions (in-thrust-we-trust some more), but really, the majority of air dominance focus today is on further stealth improvements, more powerful electronic warfare / information warfare capabilities and directed energy weapons from more powerful jammers to masers and lasers. Being able to sustain even 30 deg/s won't help if your enemy has a laser turret and can simply burn your fuel tanks open or send molten debris into your air intake, from any angle.

 

[dark sidius]

Sure the laser weapon can be a game changer.

 

[Sundog]

Top speed can be increased with further engine revisions (in-thrust-we-trust some more), but really, the majority of air dominance focus today is on further stealth improvements, more powerful electronic warfare / information warfare capabilities and directed energy weapons from more powerful jammers to masers and lasers. Being able to sustain even 30 deg/s won't help if your enemy has a laser turret and can simply burn your fuel tanks open or send molten debris into your air intake, from any angle.

I seriously doubt the F-35 is going to get any faster. The airframe simply isn't designed for it, as it can barely go supersonic as it is. They could put more thrust in it, but more thrust, in general, means more fuel. If they did any upgrades to the engine it would most likely be to increase longevity (increasing a higher thrust ability and dialing it back increases the life of the engine).

 

[sferrin]

I seriously doubt the F-35 is going to get any faster. The airframe simply isn't designed for it, as it can barely go supersonic as it is.

Mach 1.6 is "barely supersonic" huh? :

 

[SpudmanWP]

I seriously doubt the F-35 is going to get any faster. The airframe simply isn't designed for it, as it can barely go supersonic as it is.

Supercruise, armed, at Mach 1.2 is "barely"?

 

[bobbymike]

I seriously doubt the F-35 is going to get any faster. The airframe simply isn't designed for it, as it can barely go supersonic as it is.

Supercruise, armed, at Mach 1.2 is "barely"?

Wasn't there a thread that asked and got answered that there basically have been no supersonic dogfights? So M1.6 is probably sufficient?

Also I am curious how fast are non-stealth external carriage aircraft are or how fast they can dogfight with 10 missiles hanging off the wings and hardpoints?

 

[SpudmanWP]

Wasn't there a thread that asked and got answered that there basically have been no supersonic dogfights? So M1.6 is probably sufficient?

Yes, I was just demonstrating that if it could maintain M1.2 on dry thrust then then it's speed & acceleration with afterburner should be quite nice.

Also I am curious how fast are non-stealth external carriage aircraft are or how fast they can dogfight with 10 missiles hanging off the wings and hardpoints?

Here is an energy chart for the Superhornet that shows that it is actually slower than the F-35 while similarly armed.

 

[RadicalDisconnect]

I seriously doubt the F-35 is going to get any faster. The airframe simply isn't designed for it, as it can barely go supersonic as it is.

Supercruise, armed, at Mach 1.2 is "barely"?

Actually, I believe it's Mach 1.2 at min afterburner, which for a loaded plane is still decent I suppose.

That said, given the F-35's immense sensor and avionics edge, I think the F-35 should more than holds it's own in air to air. It is not an F-22, but it's substantially better as an overall package compared to competitors.

But let's save this for the F-35 thread.

 

[marauder2048]

But let's save this for the F-35 thread.

Has it been unlocked?

 

[dark sidius]

I can't imagine USAF have only the F-35 in the futur for air dominance with J-20 and PAK-FA competitor, it will be a terrible mistake, the F-35 is a stealth attack plane and realy nothing else all of his performance are Under the futur adversary in air combat you can't just live with the electronic for performance in dogfight bybye.

 

[sferrin]

But let's save this for the F-35 thread.

Has it been unlocked?

God, I hope not. It drug the whole forum down IMO.

 

[Sundog]

The F-35A can supercruise, but I'm not sure about the other models. I remember they added 8 seconds to the F-35A's transonic acceleration time, 16 seconds to the F-35B's and 43 seconds to the F-35C's and reduced their sustained turn rate capability by aprroxiamtely 10%, with the exception of the F-35C, because of it's big wing, I'm assuming.

It was not designed to supercruise, though it does have a lot of installed thrust that allows it to do so. By that standard, we could just put more powerful engines in the F-15 and F-16 and have them supercruise as well. Being able to supercruise is one thing. Being able to do so efficiently is something else entirely.

 

[Sundog]

Yes, I was just demonstrating that if it could maintain M1.2 on dry thrust then then it's speed & acceleration with afterburner should be quite nice.

That's a false assumption. The F-35 has incredibly high drag in the transonic region. Drag drops as you transition from transonic to supersonic speed, which is why it can supercruise at Mach 1.2. It's also why the YF-22 had to use afterburner to become supersonic before it could start supercruising, at least with the P&W YF-119 engines. I don't recall if it went supersonic on dry thrust with the GE YF-120's.

 

[Sundog]

I can't imagine USAF have only the F-35 in the futur for air dominance with J-20 and PAK-FA competitor, it will be a terrible mistake, the F-35 is a stealth attack plane and realy nothing else all of his performance are Under the futur adversary in air combat you can't just live with the electronic for performance in dogfight bybye.

The F-35 was not designed to dogfight. It was designed to sort of be a combination of an F-117A that has pretty good self defense capabilities, and has the power of a bunch of mini networked AWACs. Dogfighting is what the F-22 was designed to do. I doubt the F-35 would encounter the J-20 or the PAK-FA, at least not on the U.S. side of the ledger. The F-22's would take on those while the F-35 hit ground targets and have to maybe go up against a J-10 at most. It's not like Russia is going to have a hell of a lot of T-50's or China J-20s. Those countries are learning the same lessons the U.S. has learned; stealth ain't cheap.

 

[bobbymike]

Yes, I was just demonstrating that if it could maintain M1.2 on dry thrust then then it's speed & acceleration with afterburner should be quite nice.

That's a false assumption. The F-35 has incredibly high drag in the transonic region. Drag drops as you transition from transonic to supersonic speed, which is why it can supercruise at Mach 1.2. It's also why the YF-22 had to use afterburner to become supersonic before it could start supercruising, at least with the P&W YF-119 engines. I don't recall if it went supersonic on dry thrust with the GE YF-120's.

What is the comparison to a fourth generation fighter with all external hard points loaded?

 

[F-14D]

Yes, I was just demonstrating that if it could maintain M1.2 on dry thrust then then it's speed & acceleration with afterburner should be quite nice.

That's a false assumption. The F-35 has incredibly high drag in the transonic region. Drag drops as you transition from transonic to supersonic speed, which is why it can supercruise at Mach 1.2. It's also why the YF-22 had to use afterburner to become supersonic before it could start supercruising, at least with the P&W YF-119 engines. I don't recall if it went supersonic on dry thrust with the GE YF-120's.

What is the comparison to a fourth generation fighter with all external hard points loaded?

Actually, the comparison wouldn't be to a 4th or 4.5 gen fighter with all hard points loaded, but one with two GBU-31 and two AIM-120, because that's what in the internal bay when the F-35 supercruises @ M1.2. From what I can pick up, both the Gripen E and Typhoon can do it, but only with missiles 2 (Gripen) or 4 (Typhoon) BVR + 2 WVR (both), not with 2 BVR + 2 2,000 lb LGB.

 

[sferrin]

I can't imagine USAF have only the F-35 in the futur for air dominance with J-20 and PAK-FA competitor, it will be a terrible mistake, the F-35 is a stealth attack plane and realy nothing else all of his performance are Under the futur adversary in air combat you can't just live with the electronic for performance in dogfight bybye.

The F-35 was not designed to dogfight.

That's the kind of brainless tripe one would find on KeyPub. In case you hadn't noticed this isn't an F-35 thread.

 

[DrRansom]

Better question:

Will the F/A-XX be designed to dogfight or to fly fast and high? Either or is too strong, but perhaps more of a bias towards one end.

For the Navy, I can see why they'd want something to fly fast to serve as fleet air interceptor.

 

[donnage99]

Wasn't there a thread that asked and got answered that there basically have been no supersonic dogfights? So M1.6 is probably sufficient?

There has never been supersonic dogfight does not mean that supersonic speed, and acceleration do not play an essential role in air combat. Air combat is almost dictated by geometry advantage. And how do you get that geometry advantage - stealth, speed, and acceleration.
Secondly, any comparison of sort of a this aircraft vs that aircraft is not very relevant. With the limited number of f-22 for NATO force, it's obvious that f-35 will have to fill in the first day of war/over enemy's territory air combat, and have to face not just the enemy's aircraft sensors but a combination of complex and a variety of ground and air sensors. A safe assumption is that the f-35, with its limited and x-band focused stealth, will be detected before it could climb to an advantageous position. This means that there will be a stage in which both the f-35 and its peer or near peer opponent will see each other with advanced sensors, then race to get to an advantageous position to loose its missile. The question is - will it race there fast enough?


So yes, speed, acceleration, altitude, all so relevant and important.

 

[donnage99]

For the Navy, I can see why they'd want something to fly fast to serve as fleet air interceptor.

The navy hasn't really cared for fleet interceptor for the past 20 years. What it wanted and still want is a deep strike dream machine - ultra stealth, ultra range, with good payload, all of which will compromise speed. All of this could change depend on the political climate though. Though I would still bet that Navy would trade speed for range any day.

 

[DrRansom]

The USN hasn't faced bomber threat for the past 20 years. With China getting their cruise missile act together, it is likely that the US will want some form of Outer Air Defense in the near future.

Though if you want range, stealth, and persistence, buy a UCAS and be done with it.

 

[RadicalDisconnect]

I can't imagine USAF have only the F-35 in the futur for air dominance with J-20 and PAK-FA competitor, it will be a terrible mistake, the F-35 is a stealth attack plane and realy nothing else all of his performance are Under the futur adversary in air combat you can't just live with the electronic for performance in dogfight bybye.

The F-35 was not designed to dogfight.

That's the kind of brainless tripe one would find on KeyPub. In case you hadn't noticed this isn't an F-35 thread.

How about this, the primary design drivers of the F-35 isn't close-in dogfighting, or having F-22/Typhoon/PAK FA level kinematics. That said, given the F-35's likely significant advantages in stealth, avionics, and sensor fusion (the amount of money pumped into F-35 software is telling), it likely doesn't need world class aerodynamics.

But again, this is getting way off topic. I'm actually wondering if variable-cycle technology in the AETD and VCAT programs for 6th gen will find its way back to the F-22 and F-35.