On Thu, 05 Jun 2014 06:38:42 +0100, Phil W Lee
wrote:

John B. considered Wed, 04 Jun 2014
08:49:14 +0700 the perfect time to write:

On Tue, 03 Jun 2014 04:25:16 +0100, Phil W Lee
wrote:

John B. considered Wed, 28 May 2014
07:57:25 +0700 the perfect time to write:

On Tue, 27 May 2014 01:39:34 +0100, Phil W Lee
wrote:

Frank Krygowski considered Sun, 25 May 2014
22:51:30 -0400 the perfect time to write:


The problem is that the exact fuel burn curve is different for every
airframe and engine combination, and the Vulcan had not had any
in-flight refueling capability since it's earliest days - and when it
DID have it, it was intended to be used in combination with a single,
high yield bomb or missile, of relatively light weight, where even
brim-full tanks would give something like 8 or 9 tons lower gross
weight, and with the earlier, slightly less powerful (and more
economical) engines, not the Olympus 301s as fitted to all of the

But the fuel use to gross weight equation is common to all aircraft
and the Vulcan people must have know about it. After all a jet burns a
vast amount of fuel just to get off the ground and to cruising
altitude - which admittedly combines gross weight and operation in
denser air, but still...

You've just demonstrated how little you know about aerodynamics.
The equation may be the same, but the variables that you have to plug
into it are different (as already noted, for each airframe and engine
fitment) - and they didn't have them.

Stop being ridiculous. I said that the equation is common to all
aircraft not the details. But if you say that the RAF flew the
aircraft from 1956 when they apparently entered service until 1984
when they flew to the Falklands without ever considering the fuel
use/weight characteristics of the aircraft, I can only say that the
RAF must have gone down hill at a remarkable rate since the Big War
ended.

All the had were the (fairly coarse) graphs in the operations manual,
which didn't go high enough. And the pocket calculator wasn't up to
the job of extrapolating from them without the formulae from which
they were derived.

So not only was there no current data on what the fuel consumption at
that loading would be, there never had been any.

Perhaps not but certainly the effects of full fuel loads combined with
large bomb loads must have been known.

No, they weren't.
No Vulcan had ever been flown at that total weight before, ever.
And since so much fuel is normally burned in takeoff and climb, and
the Vulcan had never had a properly functioning in-flight refueling
system, the cruise consumption had never been established at anything
even close to that weight, only at max takeoff weight minus takeoff
and climb fuel burn, which is considerably lower.

Slow down there. The RAF must have known what fuel consumption was for
a max gross take off and climb to altitude as that is probably the
most critical portion of an aircraft flight plan as it takes a
considerable portion of the fuel load just to get off the ground and
get to altitude.

And I can't believe that there weren't air density or pressure tables
to correlate that information. Twenty years before the Falkland flight
those figures were in common use even for ground grunts. I can
remember calculating temperature, vapor pressure and pressure altitude
to calculate the horsepower output for a recip engine. The charts were
even printed in the maintenance manual.

The British bombers in WW II made some pretty long flights and I can't
believe that fuel management was a mystery to them.

Remainder snipped
--
Cheers,

John B.
(invalid to gmail)