Random thought: I wonder if the modifications would translate to an F-35 or if the internal wing structure is too different. Not sure if the F-35 was designed for jetisonable tanks, where as this was part of the original F-22 program.
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I thought there was a study back in the early days, maybe associated with FB-22? Having trouble finding them again so I'm not sure if they were official, company, or fantasy.
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Dreamfighter
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As I remember it without getting into documents or books, in the early days (pre-1997) there was thinking about / early development of stealthy underwing fuel-tanks for the F-22A, but those were cancelled during the F-22´s EMD phase (for budgetary reasons). Seems it will get these now after all, or at least something very similar. No stealthy weapons-pods were intended for the F-22A (at least never publicly). In the 2000s, the FB-22 design was shown with stealthy underwing weapons-pods, but I´m not sure how reliable/official those images were. Though I think they were quite reliable, as LM´s FB-22 design changed from a widened & upscaled F-22A to an elongated F-22A fuselage with a very large wing.
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I'm curious the impact of the signature if those are supposed to truly be LO tanks and pods. I can see the argument from the front and rear but 3/9 line the RCS will certainly bloom giving at best a "bow tie" RCS pattern in X-band. It could be much worse in lower frequencies too. I'm guessing the concept of ops will be to ingress with the tanks and if the mission requires penetration drop the tanks. I'm wondering how many jets will carry the IRST pods too. I.e. are they going to be carried on every jet or maybe just a couple per flight?
lantinian
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The ones on the artist impression are definately just stealty supersonic fuel tanks. It will be hard to keep the supersonic design if you also add weapons.
There are stories from Syria that F-22s with already spent weapons were refueled to keep them the air because of how usefull they were even unarmed. So I think they are addressing the right shortcomings: low fuel load and lack of IRST
Those pods are more than irst. You don't hang two large pods under the wings just for an optical sensor when LM has already developed stealthy conformal pods (F-35) or Legion pod shows what could be the way to follow.
Staring sensor, podded, don't even look like that.
Then there is the fish eyes/cross eyes aspect of this installation. IMOHO those are either EW or directed energy pods.
Staring sensor, podded, don't even look like that.
Then there is the fish eyes/cross eyes aspect of this installation. IMOHO those are either EW or directed energy pods.
icyplanetnhc (Steve)
Trekking into the cosmic ocean
I'm transferring my post from the YF-23/F-23 thread to avoid taking it further off topic. This summarizes what I think is the design lineage of the F-22 configuration that we see today, and also noted by several other members here.
Based on articles and diagrams from Lockheed Martin's Code One, the current F-22 can trace a significant part of its fuselage and wing configuration to General Dynamics' ATF proposal for Dem/Val RFP. That proposal was optimized for supercruise and maneuver, but struggled with all-aspect stealth due to the single large vertical tail and rather messy wing trailing edge.
After the RFP down-select, in the summer of 1987, the baseline 595-6 design proposal with trapezoidal wings and four tails was abandoned, and a variety of configurations was explored, with wings ranging from trapezoidal to diamond-like delta and empennage ranging from two tails to four tails. Out of the various proposals, it appears that 607-0 with diamond wings similar to General Dynamics' proposal and four tails evolved into the 614, which became the chosen configuration onwards. This configuration appeared to have issues with wave drag that wasn't solved until the thrust reverse requirements were deleted, which presumably allowed the rear fuselage to be slimmed down. Even so, the YF-22's, design 1131/631 (thrust reverser were deleted in 1132), supercruise performance was generally noted to be inferior to the YF-23's. As the design evolved into the 638 EMD proposal configuration, the rear fuselage appears to be further slimmed down, while the vertical stabilizers were decreased in size. The further decrease in cross-section likely improved wave drag characteristics, although I suspect that it may also have reduced the aircraft's fuel load.
The 645 design of the actual EMD/production aircraft reported had essentially the same OML, but based on a schematic I saw of the EMD proposal, some panel edges were redesigned presumably to improve observables; for instance, where the fuselage transitions to the nozzle structure, the EMD/production aircraft has fewer and larger serrations than the proposal. I believe the weapon bay door serrations were enlarged as well.
F-22 design evolution from Code One.
A chart of the design evolution from overscan.
To summarize, I think the lineage of the F-22 (tailed diamond-like delta) can be summarized as follows, starting from the summer 1987 "fire drill":
607-0 (GD-like proposal with 4 tails) -> 614 (chosen configuration in summer 1987) -> 1132/632 (YF-22 design) -> 638 (EMD F-22 proposal) -> 645 (EMD/production F-22).
Based on articles and diagrams from Lockheed Martin's Code One, the current F-22 can trace a significant part of its fuselage and wing configuration to General Dynamics' ATF proposal for Dem/Val RFP. That proposal was optimized for supercruise and maneuver, but struggled with all-aspect stealth due to the single large vertical tail and rather messy wing trailing edge.
After the RFP down-select, in the summer of 1987, the baseline 595-6 design proposal with trapezoidal wings and four tails was abandoned, and a variety of configurations was explored, with wings ranging from trapezoidal to diamond-like delta and empennage ranging from two tails to four tails. Out of the various proposals, it appears that 607-0 with diamond wings similar to General Dynamics' proposal and four tails evolved into the 614, which became the chosen configuration onwards. This configuration appeared to have issues with wave drag that wasn't solved until the thrust reverse requirements were deleted, which presumably allowed the rear fuselage to be slimmed down. Even so, the YF-22's, design 1131/631 (thrust reverser were deleted in 1132), supercruise performance was generally noted to be inferior to the YF-23's. As the design evolved into the 638 EMD proposal configuration, the rear fuselage appears to be further slimmed down, while the vertical stabilizers were decreased in size. The further decrease in cross-section likely improved wave drag characteristics, although I suspect that it may also have reduced the aircraft's fuel load.
The 645 design of the actual EMD/production aircraft reported had essentially the same OML, but based on a schematic I saw of the EMD proposal, some panel edges were redesigned presumably to improve observables; for instance, where the fuselage transitions to the nozzle structure, the EMD/production aircraft has fewer and larger serrations than the proposal. I believe the weapon bay door serrations were enlarged as well.
F-22 design evolution from Code One.
A chart of the design evolution from overscan.
To summarize, I think the lineage of the F-22 (tailed diamond-like delta) can be summarized as follows, starting from the summer 1987 "fire drill":
607-0 (GD-like proposal with 4 tails) -> 614 (chosen configuration in summer 1987) -> 1132/632 (YF-22 design) -> 638 (EMD F-22 proposal) -> 645 (EMD/production F-22).
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Published supercruise number with the F119 went from Mach 1.43 to Mach 1.72. Published fuel load went from 22,000lb to 18,600lb. If you look at the bottom of the rear fuselage the F-22A is very different than the YF-22.
icyplanetnhc (Steve)
Trekking into the cosmic ocean
I wouldn't say that the increase in the F-22's performance is solely due to the reshaped aft geometry and improved drag characteristics (there were other changes as well); the YF119 was considerably less powerful than the production F119, as the former did not have the enlarged fan to increase thrust due to the ATF's increasing weight (unlike the YF120, which did have an enlarged fan compared to the XF120). The difference in static thrust ratings is nearly 20%. Of course, in terms of dynamic thrust, it's difficult to characterize how much the enlarged fan would affect the right side of the envelope. As an overall system, even though the F-22 can achieve about Mach 1.8 without afterburners, the supersonic design point by all accounts is Mach 1.5, where it would be the most efficient in terms of supersonic performance.
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Didn't say anything other than the F-22A lost fuel, got skinnier, and goes faster.
edit: I seem to recall P&W saying something like, "the YF119 was sized for a 50,000lb aircraft while the YF120 was sized for a 60,000lb aircraft". The ATF requirement had been for a 50k aircraft later relaxed to a 60k aircraft.
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FighterJock
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I wonder how fast the F-22 actually is sferrin? I have heard many rumours that it has the capability to fly at Mach 2 with full afterburner, I have remained sceptical about this for many years.
Forest Green
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The internal fuel fraction of the F-22 has always seemed a little low to me. Usually it's just the difference between the empty and full weight, which is 21,500lb. I guess it depends whether it's usable fuel or full fuel?
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Which issue if I may ask, I could use that.
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The notion that it could cruise at Mach 1.72+ without afterburners but couldn't bust Mach 2 with them is
X-39
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Well, the specs listed in the article are meant for the 6th Gen, alluding it will have superior performance over the Rptor, at least that's the way i interpreted it. The F-22 tops at 66k feet, 4k feet shy of the conceived ceiling of NGAD. Same with the Mach 2.8. Honestly, i would be surprised if it can reach those speeds, but the problem is that even if the airframe can sustain the heat, the (current) RAM coatings cannot, hence the software limit to mach 2.0. I remember someone talking about a pic of it with RAM smeared over the canopy when they puhed it too far, Surely the solar like pannel tiles being tested for NGAD will have new properties that will enable if to fly at it's maximum potential.
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Temperature spec for the coatings is sustained 250f
To be pedantic, I think 260F is the value.
Years ago, I posted an arrested temperature chart. It is there, somewhere. But I am not gonna dig the Bot infested aerospace web forums myself.
Here what I quickly find via a quick ggl search. If
that help anyone, feel free to repost/link here to complement.
Best,
TViP
Years ago, I posted an arrested temperature chart. It is there, somewhere. But I am not gonna dig the Bot infested aerospace web forums myself.
Here what I quickly find via a quick ggl search. If
that help anyone, feel free to repost/link here to complement.
Best,
TViP
icyplanetnhc (Steve)
Trekking into the cosmic ocean
Mach 2.8 was Air Force Mag's speculation for the NGAD's potential top speed. The F-22 operationally is Mach 2 class, with the RAM coatings likely being a limiting factor. Even without that limitation, the top dash speed is probably not much different from an F-15 (with a time limit), but frankly, the top dash speed just isn't a particularly important characteristic and has very little operational value.
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oh keypublishing, it is insane how quickly that forum die after the redesign. I think they lost 99%member after the update
F-2
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I’ve heard mach 2.4, more then that the FCS stops you to protect the plane. Pretty consistent with the Eagle’s 2.5
Dreamfighter
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It was here, in an article about NGAD:
Piecing Together the NGAD Puzzle | Air & Space Forces Magazine
The Next-Generation Air Dominance family of systems remains highly classified. But some details are beginning to emerge.
www.airforcemag.com
At the start of the 'Flight Performance' paragraph;
"The primary aircraft of NGAD is likely to fly at least as high and fast as the F-22, meaning an upper ceiling of about 65,000 to 70,000 feet and a top speed of about Mach 2.8."
I think we shouldn’t read too much into NGAD predicting but I’d be shock if it didn’t super cruise. The problem with the distances the Pacific theater imposes are not just range but also response time. Additionally, super cruise would give a larger, less maneuvering airframe a lower window of vulnerability. I suspect achieving high Mach dry thrust speeds on top of long range is a key goal of NGADs manned platform.
Rationally, no.
- The short sentence has plenty of zeros to discard a typo error only on the Mach nbr.
- The associated text that comes with the value is unambigious ("top speed").
- Mach 2.8 is converging with the known max sustainable material temperature.
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Interesting. There was a comment by Paul Metz, on one of the many cable shows back in the 90s, wherein he said regarding the F-22A, "it's fast. I mean it's really fast. The top speed is classified but it will do 1600 miles per hour."
It was here, in an article about NGAD:
Piecing Together the NGAD Puzzle | Air & Space Forces Magazine
The Next-Generation Air Dominance family of systems remains highly classified. But some details are beginning to emerge.
At the start of the 'Flight Performance' paragraph;
"The primary aircraft of NGAD is likely to fly at least as high and fast as the F-22, meaning an upper ceiling of about 65,000 to 70,000 feet and a top speed of about Mach 2.8."
There was another quote by a pilot saying, "when you're cruising at Mach 1.9 and 60,000 feet. . ." and another about the F-22 being able to supercruise at sea-level.
Dreamfighter
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Interesting. There was a comment by Paul Metz, on one of the many cable shows back in the 90s, wherein he said regarding the F-22A, "it's fast. I mean it's really fast. The top speed is classified but it will do 1600 miles per hour."
It was here, in an article about NGAD:
Piecing Together the NGAD Puzzle | Air & Space Forces Magazine
The Next-Generation Air Dominance family of systems remains highly classified. But some details are beginning to emerge.
At the start of the 'Flight Performance' paragraph;
"The primary aircraft of NGAD is likely to fly at least as high and fast as the F-22, meaning an upper ceiling of about 65,000 to 70,000 feet and a top speed of about Mach 2.8."
There was another quote by a pilot saying, "when you're cruising at Mach 1.9 and 60,000 feet. . ." and another about the F-22 being able to supercruise at sea-level.
I too remember Paul Metz making that comment a long time ago, and IIRC it was in a video I once saw from when he was still an F-22 test-pilot ...
Only thing I can find back about it, are some other aviation-sites/pages referring to that same statement from Metz, sometimes also linking to the original source but every time that source (the video or the interview in which he said it) seems to have disappeared.
At 60.000 ft and 216K temperature, 1600 mph would be Mach 2.42
So it´s "classified top-speed" could indeed be somewhat higher. Even '1600 mph' is probably still classified.
icyplanetnhc (Steve)
Trekking into the cosmic ocean
I wouldn't read too much into this statement. Again, this is AFM's speculation that the NGAD may be able to achieve a level of performance equal to or greater than the F-22's, so it doesn’t really tell much about the latter’s actual performance. The F-22's top dash speed likely isn't much different from an F-15, and operationally it would be of little value, especially if speeds above Mach 2 places excessive wear on the RAM skin, which is already a very maintenance-intensive aspect of the aircraft.It was here, in an article about NGAD:
At the start of the 'Flight Performance' paragraph;Piecing Together the NGAD Puzzle | Air & Space Forces Magazine
The Next-Generation Air Dominance family of systems remains highly classified. But some details are beginning to emerge.
"The primary aircraft of NGAD is likely to fly at least as high and fast as the F-22, meaning an upper ceiling of about 65,000 to 70,000 feet and a top speed of about Mach 2.8."
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BDF
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Fair enough, I just feel that this comment from the AFA was, as already pointed out, highly speculative and shouldn't be given too much weight. I'd be happy to be dead wrong though! FWIW I have no doubt that the F-22 can easily do the M2.4ish if the restrictions were ignored.
FighterJock
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Yep. Ain't it cool?
siegecrossbow
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I wouldn't read too much into this statement. Again, this is AFM's speculation that the NGAD may be able to achieve a level of performance equal to or greater than the F-22's, so it doesn’t really tell much about the latter’s actual performance. The F-22's top dash speed likely isn't much different from an F-15, and operationally it would be of little value, especially if speeds above Mach 2 places excessive wear on the RAM skin, which is already a very maintenance-intensive aspect of the aircraft.It was here, in an article about NGAD:
At the start of the 'Flight Performance' paragraph;Piecing Together the NGAD Puzzle | Air & Space Forces Magazine
The Next-Generation Air Dominance family of systems remains highly classified. But some details are beginning to emerge.
"The primary aircraft of NGAD is likely to fly at least as high and fast as the F-22, meaning an upper ceiling of about 65,000 to 70,000 feet and a top speed of about Mach 2.8."
I don’t see the operational need to operate above Mach 2 unless you need to intercept supersonic bombers. That said, could fourth gen fighters even hit Mach 2 with standard weapon load out?
Dreamfighter
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Or unless one wants/needs to intercept 'very fast things' other then supersonic bombers, or when time is extremely critical.
Or to add just a little bit more launch-velocity or range to a missile-shot in some circumstances.
Or to get away from something extremely fast.
But in most operational circumstances Mach 1.5 to Mach 2 will do fine.
I think F-15 is capable of Mach 2 with up to 4 AAMs beneath it´s fuselage.
MiG-31 probably too?
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