Lockheed Martin F-22 Raptor

[siegecrossbow]

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?

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?

Mig-31 is a dedicated interceptor optimized for high speed performance.

Do you happen to have a link for F-15? Also, are the missiles short range or medium range like AMRAAM?

 

[Firefinder]

Do you happen to have a link for F-15? Also, are the missiles short range or medium range like AMRAAM?

Likely Sparrows slash AMRAAM since you can fit four on the waist flush against the body.

Which is a very low drag set up.

Also believe the F14 could hit Mach 2 as well with four Aim54 or Sparrows in the tunnel.

 

[siegecrossbow]

Do you happen to have a link for F-15? Also, are the missiles short range or medium range like AMRAAM?

Likely Sparrows slash AMRAAM since you can fit four on the waist flush against the body.

Which is a very low drag set up.

Also believe the F14 could hit Mach 2 as well with four Aim54 or Sparrows in the tunnel.

For F-14 it definitely makes sense. One of its key roles is to fleet defense by intercepting Backfires.

 

[Dreamfighter]

Do you happen to have a link for F-15?

No, sorry. It´s just what I remember, and so certainly not 100% sure.

 

[icyplanetnhc (Steve)]

An F-15C with F100-PW-100 can touch Mach 2.1 with four conformal carriage AIM-7s or AIM-120s, or Mach 2.2 with VMAX thrust. Again, even though it can reach this speed, there is little utility or operational value, as your endurance there can be measured in minutes, perhaps.

As pointed out, even for intercepting supersonic bombers, a Mach 1.5-2 speed is more than sufficient, which is what the F-22 can operate at pretty regularly. Sure, if it ignored the operational limits imposed by the RAM skin, it can dash at similar speeds to a clean F-15, around Mach 2.4 or so, but frankly it’s pretty pointless, hence an operational maximum of Mach 2.

The MiG-31, being a dedicated interceptor, is the only aircraft meant to regularly operate above Mach 2. However, its characteristics would not be well suited for a tactical fighter, with poor maneuver performance outside of speed.

 

[TomcatViP]

I beg to differ: the max sustainable ram temperature of the 22 is above the arrested temperature of an a/c flying well over Mach 2.6. Hence, this is not about dash speed only but raw sustainable performances, aka operational limitation or max speed.

 

[icyplanetnhc (Steve)]

The RAM temperature limit is around 250 F, which correspond to roughly Mach 2 in terms of sustained skin heating. This temperature also corresponds a figure given in the book by Aronstein, Hirschberg, and Piccirillo (program manager of the ATF) on the ATF/F-22. Any speeds above this would be a time limited dash and have little operational value.

 

[Dreamfighter]

The RAM temperature limit is around 250 F, which correspond to roughly Mach 2 in terms of sustained skin heating. This temperature also corresponds a figure given in the book by Aronstein, Hirschberg, and Piccirillo (program manager of the ATF) on the ATF/F-22. Any speeds above this would be a time limited dash and have little operational value.

Well, except for the MiG-31 (and -25) as you said, for any fighter speeds above Mach 2 are (very) time limited 'dash speeds' and are rarely used.

 

[TomcatViP]

The RAM temperature limit is around 250 F, which correspond to roughly Mach 2 in terms of sustained skin heating. This temperature also corresponds a figure given in the book by Aronstein, Hirschberg, and Piccirillo (program manager of the ATF) on the ATF/F-22. Any speeds above this would be a time limited dash and have little operational value.

It's always preferable to look at scientific literature than the narrative from ppl that are probably restricted in their say.

 

[icyplanetnhc (Steve)]

Okay, and your own charts show that the ram inlet temperature (not exactly the same as skin heating from friction, adiabatic compression of the air, but an approximation) is roughly 390 K, or roughly 240 F at Mach 2.

Yes, the bismaleimide (BMI) composite structure as extensively (and expensively) used by the F-22 can see continuous use at roughly 400 F, or 204 C (477 K), but the RAM skin itself has a composition that's apparently more sensitive to high temperatures. Considering how maintenance-intensive the F-22's skin already is, I see little operational value in flying over Mach 2.

 

[TomcatViP]

at 36000ft

 

[icyplanetnhc (Steve)]

Static air temperature is relatively constant from 36,000 ft to 66,000 ft.

 

[TomcatViP]

True but density decreases, meaning that your IAS will increase while your stagnation temp will plateau

 

[icyplanetnhc (Steve)]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

 

[FighterJock]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

 

[siegecrossbow]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

 

[FighterJock]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

Could well be siegecrossbow, I never thought of that before.

 

[rooster]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

What pressing need is there to sustain speeds around 2 mach? It's one thing to have a few specialized types but you still have tremendous heat and fuel consumption and your turns require half the state of Ohio. You're not out running a missle and your IR signature is a neon light. If you want useable range that's one big flying fuel tank. Missiles need to be fast. Aircraft need to be fast enough but stealthy. Persistence and enough stealth to operate over contested airspace is more important.

Probably the canopy on the 22 won't like spending too much time over 2M.

 

[sferrin]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

What pressing need is there to sustain speeds around 2 mach? It's one thing to have a few specialized types but you still have tremendous heat and fuel consumption and your turns require half the state of Ohio. You're not out running a missle and your IR signature is a neon light. If you want useable range that's one big flying fuel tank. Missiles need to be fast. Aircraft need to be fast enough but stealthy. Persistence and enough stealth to operate over contested airspace is more important.

Probably the canopy on the 22 won't like spending too much time over 2M.

Because the Pacific is big. Same reason the MiG-31 is big and fast. Big areas to cover. Same reason basically every aircraft designed for that mission has been big. The XF-108 would be have been bigger and faster than even the MiG-31.

 

[quellish]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

No, that has the same temperature specs

 

[FighterJock]

The XF-108 would be have been bigger and faster than even the MiG-31.

A pity the XF-108 was cancelled long before its first flight. It would have been a beast of a plane to fly.

 

[siegecrossbow]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

What pressing need is there to sustain speeds around 2 mach? It's one thing to have a few specialized types but you still have tremendous heat and fuel consumption and your turns require half the state of Ohio. You're not out running a missle and your IR signature is a neon light. If you want useable range that's one big flying fuel tank. Missiles need to be fast. Aircraft need to be fast enough but stealthy. Persistence and enough stealth to operate over contested airspace is more important.

Probably the canopy on the 22 won't like spending too much time over 2M.

Because the Pacific is big. Same reason the MiG-31 is big and fast. Big areas to cover. Same reason basically every aircraft designed for that mission has been big. The XF-108 would be have been bigger and faster than even the MiG-31.

In that case range and loitering time is bigger concern than pure speed alone.

 

[sferrin]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

No, that has the same temperature specs

Not that I doubt you but where did you find out what the stuff is even made of?

 

[sferrin]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

What pressing need is there to sustain speeds around 2 mach? It's one thing to have a few specialized types but you still have tremendous heat and fuel consumption and your turns require half the state of Ohio. You're not out running a missle and your IR signature is a neon light. If you want useable range that's one big flying fuel tank. Missiles need to be fast. Aircraft need to be fast enough but stealthy. Persistence and enough stealth to operate over contested airspace is more important.

Probably the canopy on the 22 won't like spending too much time over 2M.

Because the Pacific is big. Same reason the MiG-31 is big and fast. Big areas to cover. Same reason basically every aircraft designed for that mission has been big. The XF-108 would be have been bigger and faster than even the MiG-31.

In that case range and loitering time is bigger concern than pure speed alone.

You need both. If you can't react quickly enough then you'll need more aircraft.

 

[Firefinder]

We're talking about the operational limits imposed by the sustained heating and temperature of the RAM skin. Numerous sources, including F-22 pilots I've personally spoken to, have indicated an operational limit of Mach 2.

Interesting to see that the F-22 is limited to Mach 2 because of the problem with the heating of the RAM. I hope that the NGAD will overcome this issue and not be not be affected by it.

Maybe that’s what the mirror paint is about.

What pressing need is there to sustain speeds around 2 mach? It's one thing to have a few specialized types but you still have tremendous heat and fuel consumption and your turns require half the state of Ohio. You're not out running a missle and your IR signature is a neon light. If you want useable range that's one big flying fuel tank. Missiles need to be fast. Aircraft need to be fast enough but stealthy. Persistence and enough stealth to operate over contested airspace is more important.

Probably the canopy on the 22 won't like spending too much time over 2M.

Because the Pacific is big. Same reason the MiG-31 is big and fast. Big areas to cover. Same reason basically every aircraft designed for that mission has been big. The XF-108 would be have been bigger and faster than even the MiG-31.

In that case range and loitering time is bigger concern than pure speed alone.

You need both. If you can't react quickly enough then you'll need more aircraft.

Problem is that it doesnt matter how fast you can react if you CANT REACH what you need to react to.

The F22 Raptor for all its strengths is a short legged fighter, 500 miles combat radius with tanks.

The F35 for example has over 600 miles of radius and the F15Es push 900 which is the same for the MIG31.

Going faster will just make the Raptors range short shorter. Just the fact of Aircraft design there unless you use special engines which the F22 does not.

While you can make the range longer with tankers. We dont have enough of the bloody things any more and the Navy replacement will not work since the Raptor is not fitted for the Drogue set up that they use. That not to mention that tankers themselves have limits and can increase the range only so much.

Unless the range and the 3 flow engines are better then publically said, the Raptor is going to be limited by its range til the NGAD replaces it.

 

[icyplanetnhc (Steve)]

Range is certainly an aspect of the F-22 that the USAF is not satisfied with especially for the Pacific theater of operations but your figures are quite off. The published subsonic air-to-air combat radius figures are as follows.

F-22: 590 nmi (678 miles, 1093 km)
F-35A: 750 nmi (863 miles, 1389 km)

With two 600-gal wing tanks, the F-22's combat radius is 850 nmi (978 miles, 1,574 km).

The adaptive cycle three-stream engine (XA100/XA101) is expected increase the F-35's range by 25-30%. The three-stream architecture itself currently doesn't seem to fit into the F-22, but applying the advances to the engine components is expected to result in a 17-18% range increase.

 

[F119Doctor]

Range is certainly an aspect of the F-22 that the USAF is not satisfied with especially for the Pacific theater of operations but your figures are quite off. The published subsonic air-to-air combat radius figures are as follows.

F-22: 590 nmi (678 miles, 1093 km)
F-35A: 750 nmi (863 miles, 1389 km)

The adaptive cycle three-stream engine (XA100/XA101) is expected increase the F-35's range by 25-30%. The three-stream architecture itself currently doesn't seem to fit into the F-22, but applying the advances to the engine components is expected to result in a 17-18% range increase.

Just remember that the three stream adaptive engines have the ability to increase range/persistence and increase thrust, but not at the same time. If pilot requests low bypass, high thrust supercruise performance, you are not getting the longer range simultaneously.

 

[kaiserd]

Range is certainly an aspect of the F-22 that the USAF is not satisfied with especially for the Pacific theater of operations but your figures are quite off. The published subsonic air-to-air combat radius figures are as follows.

F-22: 590 nmi (678 miles, 1093 km)
F-35A: 750 nmi (863 miles, 1389 km)

The adaptive cycle three-stream engine (XA100/XA101) is expected increase the F-35's range by 25-30%. The three-stream architecture itself currently doesn't seem to fit into the F-22, but applying the advances to the engine components is expected to result in a 17-18% range increase.

Just remember that the three stream adaptive engines have the ability to increase range/persistence and increase thrust, but not at the same time. If pilot requests low bypass, high thrust supercruise performance, you are not getting the longer range simultaneously.

Precisely - hence the “adaptive” name.

 

[Bhurki]

Just remember that the three stream adaptive engines have the ability to increase range/persistence and increase thrust, but not at the same time. If pilot requests low bypass, high thrust supercruise performance, you are not getting the longer range simultaneously.

Use cases for increased range and increased thrust don't overlap, thankfully.
(As in either is required almost entirely exclusively for different parts of the mission)

 

[rooster]

Had not seen this posted.... Nice artwork

The F-22 Is Finally Getting Some Much Needed Upgrades

The new upgrades for the F-22 have been teased both in official Air Force artworks and FY23 budget. 25 years after it entered service in the U.S. Air

theaviationist.com

 

[Forest Green]

Had not seen this posted.... Nice artwork

The F-22 Is Finally Getting Some Much Needed Upgrades

The new upgrades for the F-22 have been teased both in official Air Force artworks and FY23 budget. 25 years after it entered service in the U.S. Air

theaviationist.com

Here's a clickbait video showing much the same. Interesting about the GPS alternative.

View: https://www.youtube.com/watch?v=EJ_RtB53IIE

 

[TomS]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

 

[VTOLicious]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

Does F-35 have that capability?

 

[FighterJock]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

Does F-35 have that capability?

Probably, but the USAF won't talk about it due to it likely being classified

 

[TomS]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

Does F-35 have that capability?

Probably, but the USAF won't talk about it due to it likely being classified

To be clear, every technology I mentioned has been discussed/published in unclassified forms.

 

[Josh_TN]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

Does F-35 have that capability?

Any aircraft since the 80's has an inertial reference system of some kind. I think even an F-16C always had a laser ring gyro system. But presumably more modern, more accurate systems are incorporated now that have less drift. if my cell phone knows when its changed orientations than clearly accelerometry has gone through a lot of changes. I would think one easy option now adays would be radar ground mapping the local area to fix your position. AGM-86/BGM-109 did this with TERCOM before GPS, though they had to be loaded with specific features to look for and guide to them by INS. Back in the day the size of the library for comparisons and a lack of storage room on the aircraft would have been limitations; now I'm sure the entire globe has been SAR mapped to the foot or inch by the DMA (or whatever its called now) and you could probably store a copy on individual fighters, certainly at least the local topology of the theater you were operating in. Probably wouldn't be GPS level accurate and it would force you to briefly radiate but it would be available to an aircraft with a SAR mode in most any environment that wasn't open water.

 

[Forest Green]

AIRS on the LGM-118 had ridiculously small drift, that matched with other cross-referencing would probably work very well.

 

[VTOLicious]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

Does F-35 have that capability?

Any aircraft since the 80's has an inertial reference system of some kind. I think even an F-16C always had a laser ring gyro system. But presumably more modern, more accurate systems are incorporated now that have less drift. if my cell phone knows when its changed orientations than clearly accelerometry has gone through a lot of changes. I would think one easy option now adays would be radar ground mapping the local area to fix your position. AGM-86/BGM-109 did this with TERCOM before GPS, though they had to be loaded with specific features to look for and guide to them by INS. Back in the day the size of the library for comparisons and a lack of storage room on the aircraft would have been limitations; now I'm sure the entire globe has been SAR mapped to the foot or inch by the DMA (or whatever its called now) and you could probably store a copy on individual fighters, certainly at least the local topology of the theater you were operating in. Probably wouldn't be GPS level accurate and it would force you to briefly radiate but it would be available to an aircraft with a SAR mode in most any environment that wasn't open water.

So why would the Raptor be upgraded then?

 

[rooster]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

Muon detectors? Now we're finally getting some star trek tech. They only live for milliseconds.

 

[TomS]

GPS alternative PNT is a big field these day. You can supplement inertial with star trackers, terrain reference cameras, magnetic anomaly detectors, and even cosmic ray muon detectors.

Muon detectors? Now we're finally getting some star trek tech. They only live for milliseconds.

Cosmic rays generate them in the upper atmosphere, and there are tricky games you can use to measure the angle the rays are hitting at, which provides positioning information. Turns out it could be useful at higher latitudes where Navstar GPS is sketchy.

The Navy is testing a GPS-like device that doesn’t require satellites

The Navy is studying muons, a natural source of radiation that, unlike GPS, can be used deep underground or in the Arctic.

taskandpurpose.com