5 ms·

I don't know of any current planes that go above Mach 3. I'm not even sure if the F-22 goes above Mach 2. Outside of experimental unmanned craft, nothing goes "

I don't know of any current planes that go above Mach 3. I'm not even sure if the F-22 goes above Mach 2. Outside of experimental unmanned craft, nothing goes "substantially" faster than Mach 3.

testvox 8y ago
It can just make Mach 2 with afterburners (supposedly).
mr_overalls 8y ago
I dunno. I don't have any sort of inside info (of course), but it just seems weird to me that the US designed aircraft in the late 1950s (XB-70 Valkyrie) that could cruise at Mach 3+, but now our stealth capabilities are so good (or drones so effective in replacing reconnaissance aircraft) that those high-speed capabilities are no longer required. I can only offer speculation. The subject of mysterious military aircraft is of course a rumor mill and field of conspiracy theories like no other. :-) https://nationalinterest.org/blog/the-buzz/rumors-secret-warplanes-preceded-mach-6-sr-72-spyplane-22556 https://nationalinterest.org/blog/the-buzz/rumors-secret-war...
- PeterisP 8y ago
  Improvements in satellite imaging have reduced the need for cruising at mach 3+; the same job can be accomplished with very different hardware.
- aurailious 8y ago
  > (or drones so effective in replacing reconnaissance aircraft) It's a combo of this and satellites. The only credible rumor I believe is that a even stealthier variant of the F-117 was used in the "gap" between the SR-71 and modern drones. But since then almost all ISR is done by drones, with the rare exception when the U2 is still flown. Otherwise satellites had gotten to the point in the 90s that they could provide real time feeds so it destroyed the need for a high end recon platform like the sr-71 and all other ISR could be done by cheap drones.
avar 8y ago
Depending on your definition of "current" the MiG-25 can fly at up to Mach 3.2 (at risk of damage to the airframe) and even though it was introduced in the 70s is still in service.
- aurailious 8y ago
  Wiki says only Libya, Syria, and Algeria operate it currently. I am skeptical it has flown above Mach 3 in decades.
  - vonmoltke 8y ago
    That's because the Soviet/Russian Air Force upgraded to the MiG-31 in the late 80s. The 31 has the same performance envelope as the 25.
captain_perl 8y ago
The issue with cruise above Mach 2 is that you need a lot of fuel, exotic materials and involved processes. None of which are compatible with the civilian airline industry. From a military perspective, high cruise reduces range, involving multiple refuelings. It also doesn't help in a head-on approach, but missiles do travel at Mach 3. The costs of Mach 3 outweigh the benefits unless you have an intercept or recon mission. So the discussion should be ... "we are here, where should we go next?" I would say re-examine the X-planes results, look at where we are in materials and CFD, and do another X program. For example, all modern jets use area ruling. What is the next step in supercritical airfoils for airliners? (The current record is around Mach 0.89 for an airliner at cruise.) NASA has a great track record at basic research. How we can use fuel efficiently and inject a minimum of toxic gases into the upper atmosphere? The SR-71 burnt most of its exhausts, resulting in no soot, can airline engines do the same?

I don't know of any current planes that go above Mach 3. I'm not even sure if the F-22 goes above Mach 2. Outside of experimental unmanned craft, nothing goes "substantially" faster than Mach 3.

testvox 8y ago

It can just make Mach 2 with afterburners (supposedly).

mr_overalls 8y ago

I dunno. I don't have any sort of inside info (of course), but it just seems weird to me that the US designed aircraft in the late 1950s (XB-70 Valkyrie) that could cruise at Mach 3+, but now our stealth capabilities are so good (or drones so effective in replacing reconnaissance aircraft) that those high-speed capabilities are no longer required. I can only offer speculation. The subject of mysterious military aircraft is of course a rumor mill and field of conspiracy theories like no other. :-) https://nationalinterest.org/blog/the-buzz/rumors-secret-warplanes-preceded-mach-6-sr-72-spyplane-22556 https://nationalinterest.org/blog/the-buzz/rumors-secret-war...

PeterisP 8y ago
Improvements in satellite imaging have reduced the need for cruising at mach 3+; the same job can be accomplished with very different hardware.
aurailious 8y ago
> (or drones so effective in replacing reconnaissance aircraft) It's a combo of this and satellites. The only credible rumor I believe is that a even stealthier variant of the F-117 was used in the "gap" between the SR-71 and modern drones. But since then almost all ISR is done by drones, with the rare exception when the U2 is still flown. Otherwise satellites had gotten to the point in the 90s that they could provide real time feeds so it destroyed the need for a high end recon platform like the sr-71 and all other ISR could be done by cheap drones.

avar 8y ago

Depending on your definition of "current" the MiG-25 can fly at up to Mach 3.2 (at risk of damage to the airframe) and even though it was introduced in the 70s is still in service.

aurailious 8y ago
Wiki says only Libya, Syria, and Algeria operate it currently. I am skeptical it has flown above Mach 3 in decades.
- vonmoltke 8y ago
  That's because the Soviet/Russian Air Force upgraded to the MiG-31 in the late 80s. The 31 has the same performance envelope as the 25.

captain_perl 8y ago

The issue with cruise above Mach 2 is that you need a lot of fuel, exotic materials and involved processes. None of which are compatible with the civilian airline industry. From a military perspective, high cruise reduces range, involving multiple refuelings. It also doesn't help in a head-on approach, but missiles do travel at Mach 3. The costs of Mach 3 outweigh the benefits unless you have an intercept or recon mission. So the discussion should be ... "we are here, where should we go next?" I would say re-examine the X-planes results, look at where we are in materials and CFD, and do another X program. For example, all modern jets use area ruling. What is the next step in supercritical airfoils for airliners? (The current record is around Mach 0.89 for an airliner at cruise.) NASA has a great track record at basic research. How we can use fuel efficiently and inject a minimum of toxic gases into the upper atmosphere? The SR-71 burnt most of its exhausts, resulting in no soot, can airline engines do the same?