max altitude and Mach 1

is there a formula or chart for figuring KEAS?

--



Curiosity killed the cat, and I'm gonna find out why!
"Guy Alcala" wrote in message
. ..
Peter Stickney wrote:

In article ,
"John Carrier" writes:

snip

As to "very easily flown higher and faster" the J-79 would experience
burner
blow out between 65-70,000 feet and the engines would have to be shut
down
approaching 75,000 because their minimum fuel flow settings would be
too
high and cause overtemp. (Greenameyer intended to modify the fuel
control
and use specially formulated fuel to allow the engine to run longer
until
shutdown required in his zoom climb.)

That would be higher and faster at the same time - One very
interesting bit from the F-104A (-19) engine's SAC Chart, Jun 1970,
(If you need to see it, I'll be glad to E-mail you a copy)
Is that the ceiling is increasing as it approaches Mach 2,0/66,000'.
That's about 320 KEAS. As far as the engine is concerned, it's
being delivered 320 Kt/Sea Level conditions from teh inlet. They sure
seem
to run O.K. in that range. Of course, if you're slower, it'll be a
_lot_ different. But that's the point - With the -19 engines F-104A,
it had the power to go a lot faster than its flight limits would
allow. So it had the potential to, if you were ignoring the limits,
deliver some astounding performance.

There didn't seem to be that much problem with a J79 above 60 Kft -
the B-58 on a high altitude bomb run at Mach 2.0 would be over the
target at 64,000'.

Walt Bjorneby must be busy, or I'm sure by now he'd have mentioned his
cruising in
his F-104A w/-19 from Tyndall to Homestead at M2.0 and FL730 (he'd filed
IFR at
1,120 KTAS and that altitude). I believe he said he was using about 3/4
AB and
burning 6,000 pph.

Guy

In article ,
"John Carrier" writes:
You've asked a Short Question with a Long Answer, I'm afraid.

Peter, why do I suspect that when asked the time, you tell the inquirer how
to build a watch?

Nah. I just show them how to build a sundial.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

"Boomer" wrote in message ...
I 've noticed that many of the more modern fighters (F-16, SU-27) only reach
max alt while subsonic, whereas older fighters ( F-4, MiG-21 for instance)
reach max altitude around M 1.6 or more. Is there some general reason for
this?


Don't know where you picked up this info but it's bogus. Aircraft fly
(and stall) on indicated airspeed, which correlates with air density
(and thus developed lift). We are talking about level flight, right?
In zoom climbs you go on up until the aircraft runs out of energy and
starts falling back down. Usually it will be subsonic then but this is
in no way at a sustainable altitude. In level flight at max altitude
the faster you go the higher you can go. For instance M1.0 at 65000
gives an IAS of around 166 KIAS. This is way behind best L/D for
fighter aircraft. M2 gives double that, about 332 KIAS. A M2 16 or 27
should be able to cruise in level flight at rather better than 65000 -
barring any mechanical (engine) reason why it shouldn't be there.
Walt BJ

thanks for the feedback , but all I know is what I see right?
I have posted another note with the charts included. One chart is from
Sukhoi the others are USAF.

--



Curiosity killed the cat, and I'm gonna find out why!
"WaltBJ" wrote in message
om...
"Boomer" wrote in message
...
I 've noticed that many of the more modern fighters (F-16, SU-27) only
reach
max alt while subsonic, whereas older fighters ( F-4, MiG-21 for
instance)
reach max altitude around M 1.6 or more. Is there some general reason
for
this?


Don't know where you picked up this info but it's bogus. Aircraft fly
(and stall) on indicated airspeed, which correlates with air density
(and thus developed lift). We are talking about level flight, right?
In zoom climbs you go on up until the aircraft runs out of energy and
starts falling back down. Usually it will be subsonic then but this is
in no way at a sustainable altitude. In level flight at max altitude
the faster you go the higher you can go. For instance M1.0 at 65000
gives an IAS of around 166 KIAS. This is way behind best L/D for
fighter aircraft. M2 gives double that, about 332 KIAS. A M2 16 or 27
should be able to cruise in level flight at rather better than 65000 -
barring any mechanical (engine) reason why it shouldn't be there.
Walt BJ

1) Well, here I am again, home from reunions of the 25FIS/F86F/D and
the 319FIS/F104A.
2)One thing about charts - check where they came from. If from the
official flight manual, they're probably (not always) on the money. If
from a commercial pub, take them with large grains of salt. I'm
reminded of the posters sitting in front of display airplanes citing
such numbers as Mach 2, 2000 mile range max load 24000 pounds. Those
numbers may be true, just only not all at once.
3) 104 high cruise: Paul Martino and I did fly from Tyndall to
Homestead at M2.0 and 73000 in somewhat reduced AB. 73000 was selected
because of IFR altitudes - I just wanted to make FAA happy. I found we
could cruise at M2.0 and about 315 IAS - 315 to approximate best L/D
for the 104A. (If Paul does come through as he said he would and sends
me a copy of the DD175 flight clearance form I'll post it for y'all.)
4) Zoom: I kick myself now for not further exploring the 104/-19's
envelope. The only zoom climbs I did were with the 3b engine. Our
technique was to run out to M2.0 at the tropopause (38-43000 usually,
at latitude 25N.) Once at speed, I'd do a smooth 3-4G rotation to 45
nose high. Note that the aircraft did not lose a knot of airspeed
during this maneuver. I'd stabilize at 45 nose high and keep going up
until the airspeed neared stall - around 220IAS. Then I would slowly
nose over until at low G approximating 1/10G (Guesstimate). The IAS
'over the top' would be around 100-125 KIAS. Note that at that IAS the
aircraft did not stall because the AOA was still 'flying'. I never had
an overtemp nor a blowout but then I flew the aircraft very gently up
there. Any hamfistedness will most likely result in a duct stall and
flameout. Since the standard USAF three-needle altimeter has a
mechanical stop at about 86000 I have no idea what altitude was
actually attained but in every case except the introductory 75K zoom
when I was in combat crew training mission 86000 was well exceeded.
5) Lockheed's SURE publication indicated thrust crossed drag at about
2.36 - with the 3b engine! That crossover point with the Dash 19 would
be well over the heat limits for the airframe and canopy.
6) One of my squadron commanders once said "All the posted limits are
the maker's way of saying their guarantee doesn't cover anything past
them." I think most fighter pilots think the same way. If you need
more to get the job done, and it's there, use it. Here's where the
smart pilots (in all airplanes) make decisions based on priority - if
the choice is bend the bird versus bust your ass - screw the limits.
Walt BJ