VX-4 phantom loads

Ed Rasimus wrote:

On Thu, 10 Mar 2005 22:52:45 GMT, Guy Alcala
wrote:

Ed Rasimus wrote:

On 9 Mar 2005 08:33:25 -0800, "Bob" wrote:

The Navy did not use wing tanks on their F-4's. The normal external
tank configuration was the single centerline tank. The reason was that
wing tanks made the already cumbersome F-4 even harder to turn. Roll
rate was reduced and nose high maneuvers were harder.

The Navy bought a different centerline tank than USAF did. (Not sure,
but as I recall it was a MacAir tank for USN and a Sargent-Fletcher
for AF).

From an RF-4C stores limitation chart, the USAF used McAir and Royal Jet C/L
tanks. McAir and Sargent-Fletcher made the wing tanks. The McAir C/L
limits are somewhat higher than the Royal Jet's, but the jettison limits are
the same.

You are correct--it was the Royal Jet tank, not Sargent-Fletcher. But,
the flight load limits for the RJ tank are a lot lower than the McAir.

Here's what the chart has --
(limits are Carriage KIAS/Mach/Sym. G/Unsym G/Roll Rate/Stick Throw/Jettison
limits Min KIAS/Max. KIAS/Mach. Note: "-" means basic airframe limits apply.
Jettison limits list 3 values for below 35,000 ft., then 3 values above 35,000
feet. "NE" means "Not established"):

McAir, 0% - 10% full: -/-/+ - & -2.0/-/200/Full/NE/375 KIAS/NE/NE/420
KIAS/NE

10% - 75% full: -/-/+6.5 & -2.0/+5.2 & 0.0/150/one half/Not authorized/Not
authorized

75% - full: -/-/+5.0 & -2.0/+4.0 & 0.0/150/one half/NE/375/NE/NE/420/NE


RJ, 0% -10% full: 600/1.8/+5.0 & 0.0/+4.0 & +1.0/**/**/NE/375 KIAS/NE/NE/420/NE

10% - 75% full: 600/1.8/+5.0 & 0.0/+4.0 & +1.0/**/**/Not authorized/Not
authorized

75% - Full: 600/1.8/+3.0 & 0.0/+1.0 & +1.0/**/**/NE/375/NE/NE/420/NE

As far as jettison limits (which hadn't been addressed until this
point), let me suggest that anyone who was jettisoning the RJ tank at
the published flight conditions was looking for a belly bumping
experience. The 'rule-of-thumb' we used with good results was one G
for every 100 knots of airspeed at jettison. Going 400 KIAS? Then pull
to 4 G before hitting the button. Clean separation guaranteed.

I'll confess to only having done it about 100 times, so others may
have different experiences.

I've read similar comments by other pilotsas to actual procedures.

The Navy tank was stressed for close to aircraft limits and
with lower drag than a pair of outboard 370s made for better
efficiency all around.

Drag appears to be the same as a pair of 370s.

Drag index of 12.8 for two 370s. Drag of 9.6 for one C/L 600.

My source may be in error. I was going by the sample planning problems in the
T.O. 1F-4C-34-1-1, which list the same drag, 9.6, for a pair of 370s or a single
600 C/L, but that may be a mistake. OTOH, it does show different weights for the
two, 269lb. for the empty C/L vs. 680 lb. for a pair of empty 370s.



snip

Normally each
F-4 carried 2 Aim-7 missiles in the under fuselage cavities and four
Aim-9H or G missiles on under wing pylons.

Here you highlight one shortcoming of the C/L tank option. Two of the
four missile wells couldn't be used.

Considering the reliability of AIM-7s after a few cat shots and traps, I
imagine it wasn't a big deal. And you could always punch the tank. By 1972
USAFf-4s were normally just carrying a pair of AIM-7s in the aft wells, with
jamming or camera pods in the forward wells.

By 1972, I was just checking out in the F-4 and arriving in theater.
We were NORMALLY carrying three AIM-7s on all missions with one pod in
a forward missile well. No camera pods.

You had a different mission (H/K). Judging by photo frequency, strikers and
strike escorts were often carrying a pair of ALQ-87s in the forward wells by that
time, if they weren't carrying a strike camera in place of one of the jammers.
For instance, I've got a shot of Coe and Webb's 34th TFS F-4E waiting to tank P/S
after they'd gotten their MiG-21 on 5 Oct. 1972. They were tasked as strike
escort, and theyre carrying four AIM-9Es, plus two ALQ-87s forward and a single
AIM-7E-2 aft (they got the MiG with the other). Course, they had to sit there
and wait for the SAMs and MiGs to a greater extent than you did, plus they turned
the pods ON, so I imagine carrying a pair of them was a lot more valuable to them
than an extra (and unlikely to be used) AIM-7. The Strike escorts seem to have
felt that they were primarily there as Atoll absorbers for the strikers, and
comments by COM 7th AF (or maybe it was CINCPACAF, I forget) at the time seem to
confirm that was the case.

The 432nd MiGCAP guys seem to have carried a full load of AIM-7s and AIM-9s, but
also carried two ALQ-87s or -100s, one on each I/B.

Guy