Ed Rasimus wrote:

On Fri, 13 Aug 2004 14:24:14 -0500, "John Carrier"
wrote:


"Wolfhenson" wrote in message
. com...
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.


Well, I don't have any pubs or tacmans available, so we're going on memory,
but you number is maybe a bit low for a hard-wing F-4, real close for the
F-8, definitely too high for the 105.

Corner speed (6.5 G) for Phantom was about 425KIAS, 370 for F-8, 105 was
higher. Ed Rasimus should be able to give you some data there.

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.

For the F-105, which had a max allowable G of 8.2, the speed was
higher--generally considered around 480 KIAS. But, the fact of the
matter was that drag rose so fast at high G that you couldn't sustain
for very long--airspeed bleed off put you below corner very rapidly.
(One reason why an F-105 driver only felt comfortable in the 540-600
KIAS region!).

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.

H'mm, those numbers seem kind of high for both, as far as sustained capability
goes.

400 KTAS, turn rate in Deg./sec. (rounded off) = 19 (7g); 22 (8g).

500KTAS, turn rate in Deg./sec. (rounded off) = 15 (7g); 17 (8g); 20 (9g).

600KTAS, turn rate in Deg./sec. (rounded off) = 13(7g); 14 (8g); 16 (9g).

One source (Richardson/Spick) gives steady state turn radii and time to make a
180 for the slat-wing and hard-wing, @ M0.6 and 0.9, 10kft. The slat-wing has
the advantage, making a 180 in 15.53 sec. @ M0.6 (11.59 deg./sec.), and 13.96
sec. @ M0.9 (12.89 deg./sec.). The hard wing appears to be perhaps 10-20 deg.
or so behind. Assuming ISA, @10kft, Mach 1.0 is 638 knots. M0.6 and M0.9 = 383
and 574 KTAS respectively, so M0.6 is well under F-4 (hard) corner, M0.9 a bit
over at that height -- assuming KIAS = KCAS, 420 KCAS = 490 KTAS @10kft. OTOH
the Thuds 480 KCAS corner is slightly under M0.9; ca. 558 KTAS.

FWIW, the same source has a graph comparing the hard and slat-winged F-4's Ps
capability @ M0.9 and10kft. The hard-wing has a Ps advantage at low g (4.5g),
with the slat-wing advantaged at higher g, although the slats apparently have a
lower max. g limit, +7 vs. +7.33g.

Guy