TWINMAKER wrote:

Here is a good "what if" question. From all that I have read, the
RA-5C Vigilante seemed to be a very good photo recon aircraft -
longer range and faster than an F-4. I know the USAF used RF-4s
for a long time, but what if a deal had been made for "commonality"
in the 60s that had the USAF using RA-5Cs as the primary photo
recon bird? The large size of the Vigi would not have made much
difference on a land base (the size and fast approach speed made
them rather carrier-unfriendly, from what I understand), and if
purchased in the quantities that the RF-4 was purchased (about 500,
IIRC), the unit price would have come way down.

Was the RA-5C as good or better than the RF-4C for the recon mission?




Recently somebody posted a letter to rec.aviation.military.naval about
this. It was an exchange between to high ranking officers comparing the
RF-4B (which was in USMC service) to the RA-5 and the conclusion of it
was somewhat mixed. The RA-5 undoubtedly had the best sensor suite of
the two, but was more vulnerable. (I frankly don't know whether the
sensor capability of the RF-4C was very different from that of the
RF-4B. The former had SLAR, but I don't know about the latter.)
Anyway, the Vigilante was faster (as was pointed out by another poster),
which decreased vulnerability to some extent. It was faster primarily
because of carrying all its fuel internally, instead of having to resort
to external fuel tanks. I'm not sure, but I seem to recall reading
somewhere that they would normally be in afterburner during pretty much
their entire trip in enemy airspace. Escorting F-4s would have to
struggle to keep up because without
external fuel they wouldn't be able to do it because they'd simply run
out of fuel and with external fuel their drag was much higher.
However, the speed advantage was offset by the G-limitation of the
airframe. It was limited to something like 3Gs, which meant that it was
vulnerable to SAMs. Phantoms were often able to outmanoeuvre an
approaching SAM, but for a less agile aircraft like the Vigilante, this
would have been much more difficult.

Regards,
Ralph Savelsberg