Turning performance of SEA fighters

Seriously snipped.

Corner velocity, by definition, is the minimum speed at which you can
generate maximum allowable G-load. So, the corner for the F-4 relates
to 7.33+ G at most weights. We usually used 420 KIAS for the F-4
hard-wing. The max G, of course, could be considerably reduced based
on stores retained--even empty fuel tanks.

The F-4's I flew (non-slatted J) had a 6.5 limit in the fighter
configuration. There was a flight regime and gross weight where up to 8.5
G was permissible (around .7 mach ... which meant you had to be pretty low
otherwise the KIAS wasn't there ... and 37.5K). IIRC, the Vn diagram
tapered off from that peak of 8.5 at .7 IMN to 6.5 at approx 1.0 IMN. (I
suspect a function of fuselage bending loads as the center of lift moved
aft).

Any time we'd exceed 6.5, the maintenance types would get your G, mach and
weight and enter the performance charts to compute whether the over-G was
truly in or out of the envelope. Typical culprit was an unexpected
transonic pitch up at low altitudes.

Generally, the sustained turn rate was around 14-15 degrees/second for
the F-4 hard-wing and about 12.5-13.5 for the F-105.

Don't know where you got these numbers, but sustained for the F-4 was under
10 degrees/sec at combat altitudes and weights (we typically used 15K, 4+4,
no tanks, and 60% fuel) and was found at around 450 KIAS. The F-8 could do
just under 11 degrees/sec @ 400 in similar conditions (better wing, less
wing loading, not much less T/W). ... roughly a 1 degree/sec advantage. Of
course the Mig-21 (the adversary we trained for) was a couple better than
that. Still looking at under 15 degree/sec sustained.

Ignoring momentary pitch rates (which can be phenomenally high) current
fighters can exceed 20 degrees/second.

That is SUSTAINED!!!! The idea of holding 9 Gs for a while still makes
my vision dim sitting at the computer.

Many jets have a lower G limit (typically 7.5). I've timed the F-14 and
F-18 at airshows (do the T-bird solos do a max perf 360?). Of course,
whether or not the pilot is truly at max performance or not in the wind-up
turn is unknown, but a 360 (roll in to roll out) takes around 20-24 seconds,
somewhat less than 20/sec. I got a single seat A-4 (stripped adversary) to
20 degrees/sec (not quite sustained, I lost a couple knots) in a 360 @ 1,000
feet and 180 KIAS 1/2 flaps.

R / John

John Carrier wrote:

snip

Generally, the sustained turn rate was around 14-15 degrees/second for
the F-4 hard-wing and about 12.5-13.5 for the F-105.

Don't know where you got these numbers, but sustained for the F-4 was under
10 degrees/sec at combat altitudes and weights (we typically used 15K, 4+4,
no tanks, and 60% fuel) and was found at around 450 KIAS.

For reasons known only to the services, the USN standard for 'combat' weight is
with 60% fuel, while the USAF uses 50%.

The F-8 could do
just under 11 degrees/sec @ 400 in similar conditions (better wing, less
wing loading, not much less T/W). ... roughly a 1 degree/sec advantage. Of
course the Mig-21 (the adversary we trained for) was a couple better than
that. Still looking at under 15 degree/sec sustained.

snip

I've got one source which gives 14 deg./sec. sustained for the F-15A, 16 deg.
instantaneous. The same source claims it can sustain 7.3g at 400 kts/15kft;
it's unclear if that's KTAS or KCAS, but I'm guessing the latter. It credits
the F-5E with slightly over 11 deg. sec. sustained -- IIRC corner for it is
around 375 or so. ISTR seeing the F-16A credited with ca. 16 deg./sec.
sustained. BTW, John, I've read that the (hard-wing) F-4 could generally beat
the F-8 at low/medium altitude (once the pilots learned to use its energy
advantage), but at high altitudes the F-8's lower drag (induced, parasitic
and/or wave) gave it the advantage. What's your take?

Guy

snip

I've got one source which gives 14 deg./sec. sustained for the F-15A, 16
deg.
instantaneous. The same source claims it can sustain 7.3g at 400
kts/15kft;
it's unclear if that's KTAS or KCAS, but I'm guessing the latter. It
credits
the F-5E with slightly over 11 deg. sec. sustained -- IIRC corner for it
is
around 375 or so. ISTR seeing the F-16A credited with ca. 16 deg./sec.
sustained. BTW, John, I've read that the (hard-wing) F-4 could generally
beat
the F-8 at low/medium altitude (once the pilots learned to use its energy
advantage), but at high altitudes the F-8's lower drag (induced, parasitic
and/or wave) gave it the advantage. What's your take?

Pretty good numbers, I think.

As to the F-8 versus F-4, you presented the prevailing conventional wisdom
of the time. When I was an F-8 guy, I felt I pretty much could have the
Phantom for lunch. But there was a time or two when the individual I
opposed transformed the jet into a serious adversary, "Who IS that guy?"

The F-8 had superior PsubS under G than the Phantom at altitudes above
15,000 feet, so any kind of classic turning fight (oblique loop, etc was the
thing in the tacmans at the time) played to its advantage. The Phantom was
more controllable very slow and enjoyed superior unloaded acceleration.
That points to a VERY vertical fight.

When I finally transitioned to the F-4, I thought, "No wonder it was so easy
to beat up on this jet." But, by the 500 hour mark I had changed to, "How'd
we EVER beat up on this jet?" The F-4 was the antithesis of the
point-and-pull fighter and required a great deal of finesse to fight well
(skills that many never achieved IMO). Once mastered, you could
successfully engage just about any aircraft of its generation ... albeit a
roller with a Mig-17 was ill-advised (hear that, Duke?). Of course, once
the next generation appeared (F-14 and subsequent), there really wasn't
anyplace to take the fight they couldn't go.

R / John

On Sun, 15 Aug 2004 06:54:50 -0500, "John Carrier"
wrote:

BTW, John, I've read that the (hard-wing) F-4 could generally
beat
the F-8 at low/medium altitude (once the pilots learned to use its energy
advantage), but at high altitudes the F-8's lower drag (induced, parasitic
and/or wave) gave it the advantage. What's your take?

Pretty good numbers, I think.

As to the F-8 versus F-4, you presented the prevailing conventional wisdom
of the time. When I was an F-8 guy, I felt I pretty much could have the
Phantom for lunch. But there was a time or two when the individual I
opposed transformed the jet into a serious adversary, "Who IS that guy?"

The F-8 had superior PsubS under G than the Phantom at altitudes above
15,000 feet, so any kind of classic turning fight (oblique loop, etc was the
thing in the tacmans at the time) played to its advantage. The Phantom was
more controllable very slow and enjoyed superior unloaded acceleration.
That points to a VERY vertical fight.

When I finally transitioned to the F-4, I thought, "No wonder it was so easy
to beat up on this jet." But, by the 500 hour mark I had changed to, "How'd
we EVER beat up on this jet?" The F-4 was the antithesis of the
point-and-pull fighter and required a great deal of finesse to fight well
(skills that many never achieved IMO). Once mastered, you could
successfully engage just about any aircraft of its generation ... albeit a
roller with a Mig-17 was ill-advised (hear that, Duke?). Of course, once
the next generation appeared (F-14 and subsequent), there really wasn't
anyplace to take the fight they couldn't go.

R / John


I concur. One major factor was that the F-8 community was much like
the USAF's 479th TFW/435th TFS F-104 bunch--a group optimized for day
fighter air-superiority ops. They were the lead element of the
creation of new tactics--things like Fluid Attack and Loose Deuce
along with detailed analysis of what was really going on in vertical
maneuver, split-plane operation, and one-circle/two-circle fights. (I
freely admit that the USN was well ahead of the USAF at that point in
air/air development).

And, you highlight the demand of that era to take the fight to your
best corner of the envelope. Plus, you correctly note that the advent
of the "teen fighters" means that every corner of the modern envelope
is now available and the fight goes to the better weapon and better
trained aviator.


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
"Phantom Flights, Bangkok Nights"
Both from Smithsonian Books
***www.thunderchief.org

My F-5E chart for 5000'MSL (50% fuel, 2 AIM-9) gives a 7g corner at about
365KCAS and a sustained 7g capability at about 600KCAS for a rate of just
under 12dps. That's really honkin' for this jet...a more realistic sustained
value is about 9.5dps at 430KCAS...the curve wanders a bit, but that works
out as around 4.5g or so.
"Guy Alcala" wrote in message
. ..
John Carrier wrote:

snip

Generally, the sustained turn rate was around 14-15 degrees/second for
the F-4 hard-wing and about 12.5-13.5 for the F-105.

Don't know where you got these numbers, but sustained for the F-4 was
under
10 degrees/sec at combat altitudes and weights (we typically used 15K,
4+4,
no tanks, and 60% fuel) and was found at around 450 KIAS.

For reasons known only to the services, the USN standard for 'combat'
weight is
with 60% fuel, while the USAF uses 50%.

The F-8 could do
just under 11 degrees/sec @ 400 in similar conditions (better wing, less
wing loading, not much less T/W). ... roughly a 1 degree/sec advantage.
Of
course the Mig-21 (the adversary we trained for) was a couple better
than
that. Still looking at under 15 degree/sec sustained.

snip

I've got one source which gives 14 deg./sec. sustained for the F-15A, 16
deg.
instantaneous. The same source claims it can sustain 7.3g at 400
kts/15kft;
it's unclear if that's KTAS or KCAS, but I'm guessing the latter. It
credits
the F-5E with slightly over 11 deg. sec. sustained -- IIRC corner for it
is
around 375 or so. ISTR seeing the F-16A credited with ca. 16 deg./sec.
sustained. BTW, John, I've read that the (hard-wing) F-4 could generally
beat
the F-8 at low/medium altitude (once the pilots learned to use its energy
advantage), but at high altitudes the F-8's lower drag (induced, parasitic
and/or wave) gave it the advantage. What's your take?

Guy

Andy Bush wrote:

My F-5E chart for 5000'MSL (50% fuel, 2 AIM-9) gives a 7g corner at about
365KCAS and a sustained 7g capability at about 600KCAS for a rate of just
under 12dps. That's really honkin' for this jet...a more realistic sustained
value is about 9.5dps at 430KCAS...the curve wanders a bit, but that works
out as around 4.5g or so.

My thanks to you and John for the info.

Guy