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David L. Pulver
November 27th 03, 11:54 AM
I am wonderning what the top speed (in mph) a clean F-15C, Mirage
2000, F-16C, and MiG-29 could accelerate to in level flight at optimum
altitude (not just sea level) without afterburner. I usually see the
top clean speed and the top sea level speed (with afternburner?)
quoted, but rarely the top military power speed.

If there are any online references for non-afterburner speeds of other
supersonic jets, I'd be interested to know where to find them!



Secondary question: did the F-15 get faster recently? Reference books
of a decade or so ago tended to quote 1650 mph as top speed in clean
configuration ion a good day (etc.) but now I see figures of 1875 mph
on USAF web sites.

Any help would be appreciated.

Ed Rasimus
November 27th 03, 04:04 PM
On 27 Nov 2003 03:54:51 -0800, (David L. Pulver)
wrote:

>I am wonderning what the top speed (in mph) a clean F-15C, Mirage
>2000, F-16C, and MiG-29 could accelerate to in level flight at optimum
>altitude (not just sea level) without afterburner. I usually see the
>top clean speed and the top sea level speed (with afternburner?)
>quoted, but rarely the top military power speed.
>
>If there are any online references for non-afterburner speeds of other
>supersonic jets, I'd be interested to know where to find them!
>
>
>
>Secondary question: did the F-15 get faster recently? Reference books
>of a decade or so ago tended to quote 1650 mph as top speed in clean
>configuration ion a good day (etc.) but now I see figures of 1875 mph
>on USAF web sites.

You would probably need to have the -1-1 charts to get a number. Since
you specify "optimum altitude" the number wouldn't give you a
comparison between aircraft. My suspicion (and it has little more
going for it than that) is that with modern engines and low-drag
shapes, the number will be pretty close to .95 mach for each. The
governing factor isn't the thrust or drag so much as the transonic
shock wave with associated high drag rise. Once supersonic, many of
those aircraft could ease back out of reheat and stay super for a
while.

As for the two top speeds, it looks at a glance like the difference is
pretty close to the difference between knots and miles/hour.

John Smith
November 27th 03, 07:39 PM
"David L. Pulver" > wrote in message
om...
> I am wonderning what the top speed (in mph) a clean F-15C, Mirage
> 2000, F-16C, and MiG-29 could accelerate to in level flight at optimum
> altitude (not just sea level) without afterburner. I usually see the
> top clean speed and the top sea level speed (with afternburner?)
> quoted, but rarely the top military power speed.
>
> If there are any online references for non-afterburner speeds of other
> supersonic jets, I'd be interested to know where to find them!
>
>

Clean F-15C, F-15E, F-16s with -220, -229 engines can hold .98 to .99 Mach
in Mil power..

phil hunt
November 27th 03, 08:41 PM
On Thu, 27 Nov 2003 16:04:29 GMT, Ed Rasimus > wrote:
>
>You would probably need to have the -1-1 charts to get a number. Since
>you specify "optimum altitude" the number wouldn't give you a
>comparison between aircraft. My suspicion (and it has little more
>going for it than that) is that with modern engines and low-drag
>shapes, the number will be pretty close to .95 mach for each.

That wouldn't surprise me at all.

--
"It's easier to find people online who openly support the KKK than
people who openly support the RIAA" -- comment on Wikipedia
(Email: >, but first subtract 275 and reverse
the last two letters).

WaltBJ
November 28th 03, 03:25 AM
Don't know about the new stuff but an F104A with the J79-19 engine was
good for .97M at sea level and would accelerate to 1.05M in honest to
God level flight at 25,000, all in military power (non-AB). Did it
myself.
Walt BJ

Wingedhoof
November 28th 03, 03:32 AM
> The F-15C has better engines than the
> F-15A. Maybe that is the cause for
> the discrepancy.
>
> I think its like this:
>
> A- 25,000 lbs each
> C,E- 29,000 lbs each

Nope. Only some of the E's have the IPE (PW-229). The remainder as well as
all the A's through D's have PW-220s or PW-220Es (except for the C/D's at
Langley, Eglin, and Tyndall, and several A/B ANG units that still use the old
PW-100s).

During flight test the clean E with PW-229s easily cruised above M 1.0 at mil,
whether accelerating up to it or decelerating down to it. It is not likely the
fully loaded E can do this.

John Carrier
November 28th 03, 02:20 PM
> During flight test the clean E with PW-229s easily cruised above M 1.0 at
mil,
> whether accelerating up to it or decelerating down to it. It is not
likely the
> fully loaded E can do this.

By clean, do you mean w/o conformal tanks? By easily cruised, do you mean
accelerated through mach w/o resorting to A/B? Is this based on personal
experience?

I have little doubt the clean F-15E can sustain 1.2 give-or-take in mil ...
but the acceleration through transonic might be a problem. By the same
token, the F-14B/D's can also supercruise, but they need A/B to get there
first.

The difficulty is handling the transonic drag rise, largely a function of
the design drag characteristics of the jet. Low aspect ratio, area-ruled,
thin-winged aircraft tend to do best (think F-104, Mig-23). Drag rises
sharply starting around .92 or so and peaks around 1.1-1.2. Most aircraft
run into a wall here (particularly at military thrust) and the difference in
speeds attained is remarkably little (I found the F-8 to be a wee bit faster
in military than the F-4, but I never flew the older and cleaner Phantoms
.... the F-4H1 was reputedly good for 1.04 or so, similar to F-104). And
recent designs have generally abandoned minimum-drag configurations to
attain other, more useful, characteristics.

A/C top speeds are illusory ... sometimes I think they're based more on what
comes from marketing than engineering. The F-14 was attributed with 2.34
(it attained 2.41 ONCE in flight test and was artificially limited to 1.88
in the fleet ... though it got there easily enough). The F-18 has a 1.8
claim ... I know NO ONE who's seen close to that (so maybe once in flight
test?). The F-15 is always attributed with 2.5/1650mph ... again maybe once
in flight test? (The PsubS curves I've seen would suggest otherwise, and
perhaps nobody told them about what happens to plexiglas at those speeds.)
Of course when you hang some ordnance, drag goes up and speed goes down ...
sometimes dramatically.

If one restricts the argument to military thrust only, top speed ranges from
..92 or so (low thrust or high drag limited) to maybe 1.04. Not much of a
difference if you're trying to outrun an AIM-120.

R / John

David L. Pulver
November 30th 03, 02:50 AM
Thanks for the responses!

Scott Ferrin
November 30th 03, 03:13 AM
>A/C top speeds are illusory ... sometimes I think they're based more on what
>comes from marketing than engineering. The F-14 was attributed with 2.34
>(it attained 2.41 ONCE in flight test and was artificially limited to 1.88
>in the fleet ... though it got there easily enough). The F-18 has a 1.8
>claim ... I know NO ONE who's seen close to that (so maybe once in flight
>test?).


Sometimes I wonder if the marketing guys just go something like "well
it's got a thrust to weight of X, it's got them there fixed intakes so
it's automatically less than two, and it's not quite as streamlined as
an F-16, let's slap '1.8' on it and call it good".

Any 4th generation aircraft with fixed intakes is automatically
assigned 2 or less and if it's got variable intakes they'll give it a
2.2 or a 2.35. Those seem to be the magic criteria but I doubt
they're based on anything but numbers pulled out of somebody's
backside.

John Cook
November 30th 03, 04:06 AM
On Sun, 30 Nov 2003 03:13:36 GMT, Scott Ferrin >
wrote:


I think it has more to do with the government/military original
specifications, I would think it goes something like this..

Military "We'd like a M2.5 aircraft..."

Manufacturer "Ah but they would require a variable inlet more
development work and thats more expensive!!"

Military "so how fast can you go without all the extra expence?"

Manufacturer " about M2.0"

Military " Ok close enough"

These figures are then carried through the life of the program, even
when those figures are exceeded by a large margin..


cheers


>
>>A/C top speeds are illusory ... sometimes I think they're based more on what
>>comes from marketing than engineering. The F-14 was attributed with 2.34
>>(it attained 2.41 ONCE in flight test and was artificially limited to 1.88
>>in the fleet ... though it got there easily enough). The F-18 has a 1.8
>>claim ... I know NO ONE who's seen close to that (so maybe once in flight
>>test?).
>
>
>Sometimes I wonder if the marketing guys just go something like "well
>it's got a thrust to weight of X, it's got them there fixed intakes so
>it's automatically less than two, and it's not quite as streamlined as
>an F-16, let's slap '1.8' on it and call it good".
>
>Any 4th generation aircraft with fixed intakes is automatically
>assigned 2 or less and if it's got variable intakes they'll give it a
>2.2 or a 2.35. Those seem to be the magic criteria but I doubt
>they're based on anything but numbers pulled out of somebody's
>backside.

John Cook

Any spelling mistakes/grammatic errors are there purely to annoy. All
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Scott Ferrin
November 30th 03, 06:16 AM
>I think it has more to do with the government/military original
>specifications, I would think it goes something like this..
>
>Military "We'd like a M2.5 aircraft..."
>
>Manufacturer "Ah but they would require a variable inlet more
>development work and thats more expensive!!"
>
>Military "so how fast can you go without all the extra expence?"
>
>Manufacturer " about M2.0"
>
>Military " Ok close enough"
>
>These figures are then carried through the life of the program, even
>when those figures are exceeded by a large margin..
>
>
>cheers


I've seen it go both ways. I've seen many say a clean F-4 could no
way in hell break 2.2 clean despite the fact it reached 2.62 when it
was going for the speed record (yes I'm aware of the water injection
etc. etc.) On the other hand there was someone a while back that said
they were familiar with an individual who reached 2.83 in an F-111F
briefly even though it's generally listed as 2.5. I know I remember
reading that it was limited to five minutes at a shot over 2.2 or so
because of heating. I guess the only way to know for sure would be to
get a clean aircraft up to it's optimum altitude, top of the tanks,
and put the pedal to the metal until you either stopped accelerating,
were about to exceed heating limits, or were out of gas. LOL I wish
they'd do that for aircraft about to be retired anyway. I'd have
loved it if the Blackbird would have went out with new high marks for
speed and altitude. Oh well.

John Carrier
November 30th 03, 12:40 PM
> I've seen it go both ways. I've seen many say a clean F-4 could no
> way in hell break 2.2 clean despite the fact it reached 2.62 when it
> was going for the speed record (yes I'm aware of the water injection
> etc. etc.)

Early F-4B's were good for an easy 2.2 (skinny wing and lack of add-on
antennas) and I suspect with the right conditions and trimmed engines,
somewhat more. Best I saw was 2.05 out of a late J (S-config without the
slats) and it had the wing pylons attached. The Skyburner F-4 was the early
one with small nose and canopy ... certainly not representative of
production A/C.

On the other hand there was someone a while back that said
> they were familiar with an individual who reached 2.83 in an F-111F
> briefly even though it's generally listed as 2.5.

I've heard a number of claims for the F as well. It had higher thrust
engines and w/o pylons etc was VERY clean.

I know I remember
> reading that it was limited to five minutes at a shot over 2.2 or so
> because of heating. I guess the only way to know for sure would be to
> get a clean aircraft up to it's optimum altitude, top of the tanks,
> and put the pedal to the metal until you either stopped accelerating,
> were about to exceed heating limits, or were out of gas.

It's usually gas and (these days) airspace. The F-8U3 never exceeded 2.39
because of canopy problems. Inlet heating is also a biggie.

LOL I wish
> they'd do that for aircraft about to be retired anyway. I'd have
> loved it if the Blackbird would have went out with new high marks for
> speed and altitude.

I think they came pretty close with the last records. I asked Darryl
Greenameyer why the SR couldn't just do a nice smooth pull up from 80K for
the absolute altitude record and he said it wouldn't work.

R / John

Scott Ferrin
November 30th 03, 05:50 PM
>I think they came pretty close with the last records. I asked Darryl
>Greenameyer why the SR couldn't just do a nice smooth pull up from 80K for
>the absolute altitude record and he said it wouldn't work.
>
>R / John

It still boggles my mind that that Mig-25 made it all the way to
123,000ft.

On one of the last flights (for the Air Force anyway) when they set a
few new records the Blackbird flew one stretch of the flight at 2242
mph or Mach 3.4.

Tex Houston
November 30th 03, 06:07 PM
"Scott Ferrin" > wrote in message
...

> On one of the last flights (for the Air Force anyway) when they set a
> few new records the Blackbird flew one stretch of the flight at 2242
> mph or Mach 3.4.

The official absolute speed record still belongs to retired Major General
Eldon W. Joersz at 2,193mph set in June 1976 using the SR-71.

Tex

Scott Ferrin
December 1st 03, 12:23 AM
On Sun, 30 Nov 2003 11:07:23 -0700, "Tex Houston"
> wrote:

>
>"Scott Ferrin" > wrote in message
...
>
>> On one of the last flights (for the Air Force anyway) when they set a
>> few new records the Blackbird flew one stretch of the flight at 2242
>> mph or Mach 3.4.
>
>The official absolute speed record still belongs to retired Major General
>Eldon W. Joersz at 2,193mph set in June 1976 using the SR-71.
>
>Tex

Yep. I'm wondering if it's becuase the the "offical" gates that the
FAI recognized were at the beginning and end of the flight or
something along those lines.

Tex Houston
December 1st 03, 12:43 AM
"Scott Ferrin" > wrote in message
...
> On Sun, 30 Nov 2003 11:07:23 -0700, "Tex Houston"
> > wrote:
>
> >The official absolute speed record still belongs to retired Major General
> >Eldon W. Joersz at 2,193mph set in June 1976 using the SR-71.
> >
> >Tex
>
> Yep. I'm wondering if it's becuase the the "offical" gates that the
> FAI recognized were at the beginning and end of the flight or
> something along those lines.

Almost certainly. If going after an existing record you have to comply with
the rules. One of the easiest tasks is to go about setting records for
which nothing presently exists. Lots of point-to-point records have been
done this way. Absolute records...a different story.

As an aside, I know Eldon from his F-105 days when he was a First
Lieutenant.

Tex

Wingedhoof
December 1st 03, 02:11 AM
>> During flight test the clean E with PW-229s easily cruised above M 1.0 at
mil,
>> whether accelerating up to it or decelerating down to it. It is not likely
the
>> fully loaded E can do this.
>
> By clean, do you mean w/o conformal tanks? By easily cruised, do you mean
> accelerated through mach w/o resorting to A/B? Is this based on personal
> experience?

Yes. Yes. Yes (from the control room).

Dweezil Dwarftosser
December 1st 03, 04:21 PM
John Carrier wrote:
>
> Early F-4B's were good for an easy 2.2 (skinny wing and lack of add-on
> antennas) and I suspect with the right conditions and trimmed engines,
> somewhat more. Best I saw was 2.05 out of a late J (S-config without the
> slats) and it had the wing pylons attached. The Skyburner F-4 was the early
> one with small nose and canopy ... certainly not representative of
> production A/C.

Most of the F-4 (E-model) mach logs I saw topped out
about 1.8-1.9, with only a few FCFs pushing it to 2.2
or so.

However, in those (1970) days of slick wings (no slats)
and the short gun fairing, I did see one F-4E come out
of phase and pull a mach 2.4 FCF before returning to
the flightline at Korat. Nobody believed it - so they
checked the TAS system. It was accurate. A dirty old
warbird from the Korat flightline could still pull 2.4
without any preparation (other than pylon/stores removal).

John Carrier
December 1st 03, 07:13 PM
> However, in those (1970) days of slick wings (no slats)
> and the short gun fairing, I did see one F-4E come out
> of phase and pull a mach 2.4 FCF before returning to
> the flightline at Korat. Nobody believed it - so they
> checked the TAS system. It was accurate. A dirty old
> warbird from the Korat flightline could still pull 2.4
> without any preparation (other than pylon/stores removal).

Skinny nose and -19 (??? IIRC) engines helped I'm sure.

R / John

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