Turning performance of SEA fighters

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

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

Easy question but no easy answers.

Turn performance is going to depend on gross weight, configuration, and
density altitude. It all boils down to drag and engine performance...so
clean configurations, low fuel weights, and low density altitudes are
required to get max performance.

Unfortunately, we seldom had these when turn performance counted...we were
usually heavy and relatively high...so much of this is just an academic
discussion.

As Ed pointed out, corner is the most g for the min speed. I might add that
there is no "one" corner speed. Corner varies with the three variables I
mentioned above. Most of our energy maneuverability (EM) diagrams were
based on optimistic conditions (relatively clean and 1/2 internal fuel).
From these, here are some generalizations.

1. Corner velocities varied from the high 300s to the high 400s (indicated
airspeed...we didn't think in terms of TAS or mach, again as Ed said)...and
this varied with aircraft type, weight, and altitude.

2. Max g in the F-4 was 8.5...but you had to be running practically on fumes
to be able to get there without over-g'ing the jet.

3. A slatted F-4 at about 420KIAS could hit a little over 20 degrees per
second in instantaneous turn rate...but could not sustain this. A relatively
clean F-4E(S) at 39000+ lbs and 5000' MSL could sustain about 7.5 g's...but
had to be at about 525KIAS to do this. Sustained g in the lower 400s dropped
off to around 6g for these conditions.

4. I haven't flown the F-8 but I would imagine its numbers would be similar
but attained a slightly slower speeds.

5. An interesting comparison is the F-104G. Under similar conditions, the
Zipper had a lesser instantaneous g capability...about 15 dps (lower placard
g limit) but a higher sustained capability (around 10-12dps, depending on
which EM diagram you want to believe). Corner for the 104 was about 420KIAS
under 10,000'MSL and best 0 Ps was at about 500KIAS or so.

These numbers and observations come from personal experience in the jets and
moldy old EM diagrams!

Andy Bush


"Wolfhenson" wrote in message
om...
I have recently red that instantenious rate of turn of Vietnam vintage
supersonic
fighters is less than 15 deg/sec. What are the excat figures for F-4,
F-105 and
F-8? Please include speed and altitude.


Nemanja Vukicevic
student of aircreft engineering