Thread: F-22 Comparison
View Single Post
  #40  
Old December 4th 03, 04:25 PM
Scott Ferrin
external usenet poster
 
Posts: n/a
Default


Which is why he said the maximum speed is classified. Did you even
read what he said?


So why hasn't Air Force or manufacturer released this information?


Do you know what "classified" means?


And if
Metz is allowed to release number 2.5, this would mean that real speed is
considerably (at least M0.2) greater, which stretches the boundaries of
belief even more.


Like I said- he's the test pilot and presumably gone 2.5 and knows.
Why don't you ask *him* why he appears to be full of it in your
opinion?



Despite what much of the media would have you believe fixed inlets
mean zippo.

No, they mean very much. It is certainly POSSIBLE to make a mach2+ plane
with fixed intake, but this will do very bad things to inlet performance

in
other speeds (which are considerably more important). All your cited
examples are such cases.


Actually the Crusader III was excellent at low speeds as is the F-22.


Excellent, as compared to what?


Excellent as compared to the fighters of the day. According to the
test pilots it was far superior to the F-4 in air combat and if we'd
have had it in Vietnam it would have "eaten them alive".


Certainly inferior to even basic F8U,


And that is based on what? Your opinion?


and
massively inferior to any modern fighter.


I certainly hope so.





See above. It comes down to what is possible and what is sensible. If
solving problems of Mach2+ flight regarding *serviceable combat aircraft*
was so trivial as you make it sound, each and every modern fighter plane
would go Mach3 or more.


Where did I say that or even hint at it?


For example he
Despite what much of the media would have you believe fixed inlets
mean zippo.


And what has that got to do with going Mach 3 or more? Do you think
the inlet is the only thing that prevents an aircraft from reaching or
sustaining Mach 3?




Why haven't other manufacturers put these fixed "do-it-all" intakes to their
fighters? Why they even bother putting variable intakes, even to planes
which can't reach Mach 2.5?


2+ seems to be the magic number. They have to look at where the
aircraft is going to spend most of it's time and then design it as
such. For example pretty much every current fighter spends 95% of
it's time below Mach one so to optimize the intake for Mach 2+ would
be a bad idea. Aircraft that spend most of their time below Mach 1 or
2 but need but have the need to exceed Mach 2 more than a little bit
need intakes that can do it but are still optimized for the lower
speeds Thus the variable intake. An aircraft that is going to spend
a significant amount of time about Mach 1 would have it's intake
optimized for the higher speeds but still needs to account for the
lower speeds. This is just based on observation but the two aircraft
that I know of that fit the bill both have blow out doors to dump
excess air. Not only that why would the F-22 have these blow out
doors on the back AND those little spoilers right above the intake if
it was just fixed like an F-16 or F-18?



Engine thrust has not been a limiting factor in
fighter top speed in like 40 years.


Dry thrust certainly has been.


Fighters don't reach their max speeds on dry thrust.


My point exactly.



Besides, though F-22 thrust-to-weight ratio is truly excellent, it's not
unique.

In addition to that, F-22 also has
considerable stealth requirements. Radar-absorbing paints for example may
not be very tolerant to high speeds.


You mean like the stuff that was on the Blackbird?


SR-71 was a maintenance nightmare, and large part of it was it's skin.


Do you have any cites that mention the paint being a problem? I've
never seen it written that it was.



Could be. IIRC, YF-22 with F119 engines went something like Mach 1.4 on
supercruise (at least what was initially released). Remember, that
combination was slowest of all 4 candidates.


I know. In my opinion they should have went with the F-23 with the
F120s. But then maybe they felt the F-22 was more versitile. Why
knows?