#1 Jet of World War II

Let's just say my reply has been delayed, but here goes.


The Revolution Will Not Be Televised wrote:

On Sat, 09 Aug 2003 18:50:48 GMT, Guy Alcala
wrote:

snip

[rear fuselage tanks in Spit Vcs]

I think you may be underestimating the difficulty re the Mk V. Quill, in His
"Spitfi A Test Pilot's Story," devotes an entire chapter to "Longitudinal
Stability and Increased Range."

Yes, but a close reading of that source and others leads me to the
conclusions which follow.

Ah, now we can compare close readings and interpretations of same. Onward.

He describes the weight additions and Cg
problems that led to the installation of bobweights on the Mk. Vs, as well as the
first fitting of a 75 gallon tank to a Mk. IX (ML 186), which he flew from
Salisbury Plain to the Moray Firth and back at low altitude and economical cruise
-- this a/c had a bob-weight in the elevator system plus an enlarged horn
balance. Quill writes that "the aeroplane was unstable to start with but as soon
as I had used up the rear fuselage fuel the handling was back to normal . . ."

Precisely the same condition as experienced with the rear fuselage
tank in the P-51B. I'll admit upfront that the CoG issues with the
Spit Vc/IX airframe were more serious, but this was not a binary
issue: it came down to what level of initial instability with a full
rear tank the institution concerned was prepared to tolerate.

I suggest, on the balance of evidence I've seen (which I admit is not
comprehensive), the RAF were far more sensitive to this than the USAAF
was. A case in point is the rear fusleage tank in the P-51B/Mustang
III. The instability caused by a full 85-gallon rear fuselage tank
was no different between Mustangs in RAF colours and those in USAAF
colours, the critical difference was the institutional appreciation
involved, which saw the RAF delete it entirely while the USAAF adopted
it happily. I suggest that the USAAF approach to rear-fuselage tanks
was materially different, and a similar need for long-range escorts
for a daylight strategic bombing strategy on the part of the RAF would
have entailed a similar approach as the USAAF adopted: i.e. the
instability would have been accepted in order to achieve the desired
operational aim.

Perhaps so, but again we're talking about the Spit, not the Mustang, and the former,
as you agree, had more problems with this.

I won't go into the institutional differences in detail here, but the
whole counter-factual only works if we adopt a USAAF-like commitment
to daylight strategic bombing. Absent that commitment, with all that
it entailed in terms of forcing long-range escort capacity regardless
of the difficulties (such as CoG issues with increased internal
tankage), and there wouldn't be any RAF daylight bombing effort to
start with. Without one, the other does not follow, but if we're
positing the first, we need to accept that this would modifiy
historical RAF fighter procurement and equipment beyond the historical
norm. In short, attitudes to things like the acceptable level of
temporary instability in a Spitfire with full rear-fuselage tanks
would have to change.

We agree on all the above, but I posit that the commitment would result in a shift to
Mk. VIIIs (or Mk. IXs with similar tankage), accepting the likely temporary decrease
in production.

While he and Joe Smith felt that some longitudinal instability at the start of
the flight was acceptable (as with the Mustang), the margins seem to have been
much smaller in the case of the Spit. The Mustang's stability was judged
acceptable once the rear tank was down to somewhere between 25 and 50% (opinions
differ),

Much like the behaviour of the actual Mk IX/XVIs with rear-fuselage
tanks in 1945.

True, but those Mk.IX/XVIs also had extra fuel in the regular fuselage tanks (ca.
94-96 gallons, depending on the source) forward of the datum. And correct me if I'm
wrong, but ISTR that only those a/c with cut-down rear fuselages got the aft tanks;
the aft fuselage of those a/c should have been lighter. Add in that the regular Mk.
IX was carrying around fixed ballast in the tail, and had CGs in the 4-5.0" aft of
datum range, when the Mk. Vs were in the 8-9" range. See

http://www.fourthfightergroup.com/eagles/ab197.html

as well as various Mk.V data from the same source:

http://www.fourthfightergroup.com/eagles/spittest.html

and if you want to extend the escort range it's the amount of fuel you
can carry internally to fight and return on that determines escort radius, no
matter how much fuel you hang externally to boost endurance.

Agreed. This is why the rear-fuselage tankage issue is critical to
this speculation.

Not for combat radius/return, unless you can use rear fuselage tankage for that;
otherwise you're just extending the endurance and ferry range. The Mustang could only
retain a fraction (ca. 25-50%) of that rear tank fuel to use for combat without being
dangerously unstable, with the contemporary Spit possibly (probably?) being unable to
retain any of it; at best, it could retain the same fraction as the Mustang. The
Mustang with rear tank didn't have 269 U.S. gallons to fight and return on; it had
somewhere between 205 and 227, depending on what fraction of the aft tank capacity
allowed acceptable combat handling.

To be an acceptable long-range escort, the Spit still needed the extra forward
fuselage fuel of the later Mk. IXs and the Mk. VIIIs, plus the leading edge tanks of
the latter. The Mk. VIII carried 124 Imperial gallons internally (149 U.S), ALL of
which was usable in combat, plus whatever extra fuel usable in combat (if any) a rear
tank provided.


They key difference between the Mustang and the Spitfire here, I
suggest, is institutional, and not just a matter of engineering. The
two Mk IXs with internal capacity enlarged by Wright Field at the same
time (July 1944) are a similar example: the RAF turned them down,
while the USAAF were clearly prepared to tolerate engineering
trade-offs (such as changes to the wing structure) that the RAF
wasn't. I suggest this gives us an indication of the approach
differential involved on an institutional basis which transcends the
engineering problems.

In the case of the Spit wing it seems to have been a strength issue, at least
according to Quill

I fully accept that the Spit had less CoG margins to play with, but I
still believe the required engineering solutions were at hand. On a
chronological basis, the bob-weight issue first came into focus when
Tony Bartley returned to operations with 65 Squadron after a spell
working under Quill as a test pilot at Supermarine, in February 1942
(as mentioned in the memoirs of Quill, Bartley and the other flight
commander in 65 Sqn at the time, Geoff Wellum).

The bob weights were an immediate answer to the failure of squadrons
to properly maintain the equipped CoG of their aircraft. I suggest
that a greater institutional emphasis on maintaining correct CoG
weighting would have had an impact on this. More relevantly,
solutions to this issue which gave a much greater margin of CoG
movement were at hand, as Quill states in the same chapter, with the
trial and testing of an improved Westland elevator (October 1942) and
an increased elevator horn balance (tested early 1943). In addition,
long-range reinforcement flights from Gibraltar to Malta in October
1942 actually involved the use of a 29-gallon rear fuselage tank in
addition to the 170 gallon drop tank used in the Vcs involved. So I
suggest basic experience of rear-fuselage tankage, and measures to
combat the worst CoG issues resulting were at hand in plenty of time
to have an impact on the postulated fitting of rear-fuselage tanks in
the summer of 1943.

The difference being that the flights to Gibraltar were ferry flights, and no
formation maneuvering or combat flying with the aft tanks full was required. The
Mustangs didn't do so either, except by mistake; SOP on long missions was to take off
on the left wing tank (it had the fuel return line, so some fuel needed to be drained
from it or it would dump overboard), then switch to the aft tank once sufficient
height was reached, burn that down to an acceptable level for combat handling, then
switch to the drops and empty them before going back to the rear tank, and only then
to the main tanks.


Talking about the development of the Mk. XIV into the Mk. XVIII, Quill writes
that "the basic stability margins of this aircraft, with its more forward center
of gravity due to its heavier engine, and with the latest standard of modified
elevator and the larger vertical tail surfaces, were thought likely to be
adequate to enable the aircraft to be cleared for long-range escort duties
accepting some instability in the early stages. However, we had more difficulty
than we anticipated in reaching an acceptable standard of handling with the rear
tank in use and the war was over before it was possible to clear the aircraft
with the rear tank in full operation."

In the end, even the RAF cleared the rear-fuselage tanks for
production usage in 1945, and they were happy enough to fit half of
the tankage in the FR XIV and the full thing in the XVIII.

Again, both a/c with cut-down rear fuselages. Getting to our respective readings and
conclusions on Quill, I note that he says in the case of the Mk. 21 that he disagreed
with A&AEE on whether the Mk. 21's handling was acceptable at a certain point, and
that he felt that such handling deficiencies could be accepted to get an a/c with
superior performance into the field (he's also man enough to admit that he may have
been overconfident by this point that average squadron pilots wouldn't have had
serious difficulties, based on his own skills). Now, it may just be a question of him
not thinking to mention it, or the way he worded it, but he maentions no such
disagreement between himself and A&AEE regarding the handling of the rear fuselage
tank-equipped a/c; he just says that the handling wasn't acceptable for a long time,
and required a lot of development.

I'm certainly not going to claim, based on such flimsy evidence, that this is
definitive proof that the a/c couldn't have been flown in operations with an aft tank
with accceptable handling much earlier given sufficient motivation, especially given
your comments re the prevailing attitude of the A&AEE. But I do think it at least
suggests that the Cg problems were real and agreed to be so by both the A&AEE _and_
Quill. And that's as far as I'm prepared to gaze into my crystal ball. Your reading
may well be different.


I suggest
with the equivalent of Eaker, Spaatz and Arnold lighting fires under
people's arses to increase range in 1943, this would have happened
earlier.

Not Eaker or Spaatz; it was Arnold through Giles. From "To Command the Sky":

"Under the pressure of events in Europe, in June 1943 Arnold gave Barney Giles [DCAS]
6 months 'to get a fighter that can protect our bombers. Whether you use an existing
type or have to start from scratch is your problem. Get to work on this right now
because by January '44, I want fighter escort for all our bombers from U.K. into
Germany.'"

As to someone lighting fires for the R.A.F., that was what Pete and I were
postulating, only for the Spit IX/VIII, with the highest priority to getting increased
range British fighters in the U.K. soonest, with all other Spit improvements pushed
back. Grabbing available Mk. VIIIs first (the MTO and CBI/PTO will just have to suck
it up for a while), at the cost of MK.XII/XIV production, then either expanding Mk.
VIII production at the cost of the Mk. IX or (if possible) transitioning to Mk. IXs
with the extra leading edge tanks of the VIII, with aft fuselage tanks and whatever
airframe mods required to pack usable _combat_ fuel in.


I'm happy to accept that the Vc would have had proportionately more

CoG problems than the Mustang, but the overall problem seems
identical. Allowing for some flexibility in terms of the final
compromise (maybe a tank size between the 29-gallon ferry tank of 1942
and the 75-gallon rear tank of 1945) would seem reasonable, but
dismissing the option altogether goes too far, I think. Operational
neccessity was a powerful advocate. Absent the need to escort their
own bombers in long-range daylight raids, the RAF had no need to
pursue the issue with the same vigour and tolerance for compromises
that the USAAF had, so I don't think we can take their historical
behaviour absent this need in the first place as the ultimate
determinant factor when we speculate on their behaviour in a scenario
where this factor exists.

I agree, but see my comments re the difference between ferry fuel and combat fuel.

[Spiteful tail]

I suggested the larger Mk VIII tail for similar reasons, given that it
actually was produced in a relevant timescale. Increasing the tail
area was a significant issue, and there were moves afoot to do so in
production long before the Spiteful tail. Again, not an optimal
solution, but an improvement that works towards operational utility in
the timescale involved without major production issues coming into
play.

Sure, and that with an aft tank was next on the agenda after boosting production of
the standard Mk. VIII/leading-edge tank Mk. IX. Either of the latter should have given
us an escort radius of 250-300 miles.


The two-stage Merlin was shorter and lighter than the Griffon, but was still
about 6" longer (second stage supercharger case) and 200 lb. heavier than the
single stage Merlins, and the Mk. Vs had already been suffering from overstess
breakups due to too far aft Cg prior to the fitting of bobweights. I don't think
Mk. Vs would have worked.

Well, I appreciate your point, but I have to disagree. Remedial
measures were in hand - Quill attributes the bob-weights and horn
balance eliminated the overstressing issue, and these were in play
before the time-scale in question in the summer of 1943.

The Mk V would clearly not be optimal as a long-range escort on
performance grounds, but then neither was any wartime mark of Spitfire
on other grounds. The key issue for the adoption of the Mk V is
availability, and again, as I suggest, this would be played out at an
institutional level. We have to arrive at some manner of execution
which addresses known historical factors which work against this
speculation and the biggest of these, beyond the engineering problems
involved, was the doctrinal reluctance of RAF high command to tolerate
range increases rightly or wrongly perceived as coming at the expense
of combat performance. Without eliminating or at least addressing
that intangible, the whole scenario is a non-starter.

It's interesting to see in the Mk. IX weight and loading chart I referenced above that
the a/c (AB 197) weight includes "Ballast consisting of 5 x 17.5 lb. standard weights
is permanently fitted on a bar situated in the fuselage adjacent to the tail wheel."

Unfortunately, a similar chart for a Mk. V doesn't seem to be available on the site,
but I have my doubts that the Mk. V was carrying around any such ballast in 1943, or
if it did, so far aft. Of course, AB197 was a very early Spit IX (the report date
seems to be June 10th, 1942), so that ballast was probably reduced as more operational
equipment was added, but it at least suggests (combined with the Mk. V's further aft
Cg vs.the Mk. IX as reported in various tests on the site) that the Mk. V was pretty
much at the limit, while the Mk. IX had considerably more Cg range available.


If Mk. VIII airframes were available we would have taken them as is, and asked
for more. Even the unmodified Mk. VIII would get us to the Ruhr at least,
probably a bit further.

This would have impacted on IX production, specifically at Castle
Bromwich, which hadn't fully gone over to the IX until October 1943.
I fully appreciate the operational benefit of the VIII vs IX in this
situation, but I fear you underestimate the pressures for maximal
production which argue against converting all IX production to VIII
airframe standard. There were major political ramifications to
cutting back IX availability while there was a world-wide need for
them, including lend-lease supply to the USA and Soviets, and even
more the internal RAF requirements for offsetting wastage and
re-equipping units in combat over the Channel and in the MTO.

I don't underestimate the pressures, I just think (as you mentioned a few paragraphs
above) that if the decision had been made to go over to daylight, fighter range
extension would have increased in priority and changes would have to have been
accepted, whatever the disruption elsewhere. Because otherwise, it wasn't going to
work.

No need to - the supply of two-stage Griffons was the main bottleneck
for Mk XIV production, and there would still be unmodified Mk VIII
airframes available by the end of 1943 for conversion to Mk XIVs as
the Griffons came along.

Lots of Mk.VIIIs were what we needed, not the Mk. XIV, so we would have grabbed
those airframes.

The Mk XIV was settled long before production started in October 1943,
the number of airframe's you'd be losing in that year (six for
development work most of which didn't need massive work for Mk XIV
testing and ended up testing contra-props instead, maybe 20 for
delivery to operational squadrons) is trivial. Simply cutting out the
Mk VIII airframe allocation to the Mk XII production might free twice
as many as that.

And we'll be happy to take them, and we'll just have to accept the occasional FW-190
Jabo getting through. But we'll also take the airframes that became 610 Squadron's
Mk. XIVs in January 1944.

If we're talking about an operational need in the summer of 1943,

No, the postulated date of the decision (to go over to days) was sometime in the fall
of '43, although the exact date was a bit unclear. It seemed to be in the
September/October timeframe, but we were unable to get ACM Kramer to be more precise.

as I
am, then Mk XIV production isn't a bottleneck in terms of Mk VIII
supply until early 1944, by which time minor contractors (e.g.
Westland) could have been added to the Mk VIII production line even if
it wasn't possible to have Castle Bromwich churning them out full-time
in the short term to the exclusion of all else.

If you're positing a earlier beginning to this, e.g. at the end of
1942, then the industrial variables change, but so do the political
ones. Frankly, I can't see the RAF even attempting anything like a
significant daylight strategic campaign until the USAAF showed the way
in the spring and summer of 1943.

Agreed.

The delay in the Mk. XIV would have been a question of
development manpower available. They were still working out the bugs on the Mk.
XIV at the time, and we would have told them to put that on the back burner and
get tanks into the leading edges of Mk. IXs, convert over to Mk. VIII production,
and/or devote much more effort to qualifying a rear fuselage tank.

I don't think the Mk XIV is as big an issue as you feel it is in terms
of design load, nor the rear-fuselage tankage.

Lacking better data, we'll have to disagree on this point.


What really counted
would have been converting all IX production to VIII-standard, and for
that you'd need Castle Bromwich to join Eastleigh in producing Mk
VIIIs at a time when I just can't see the whole of Spitfire supply,
world-wide, being permitted to be disrupted to facilitate one
campaign. If you have CBAF converting to Mk VIII production from July
or August 1943, you'll have no shortage of airframes for the Mk XIV
and Mk VIII production in 1944. There was a further institutional
concern with maintaining the competitiveness of the Spitfire after the
experience of the Mk V at the MAP in 1942, and this would beed to be
addressed with the Mk XIV (and this would have been useful in 1944
anyway).

I suspect F.21
development would have been held up at Supermarine, as the Mk VIII
airframe (which was the basis of the Mk XIV) was already in series
production. This just means the RAF don't get two squadrons worth of
F.21s in spring 1945, after interminable airframe development work
throughout most of 1944 delays them anyway. No great loss there,
methinks.

See comments above.

I think we disagree over what precisely Supermarine were working on at
the end of '43 and which would subsequently have been affected by the
LR development required.

Right.

Frankly, I don't think much development was
required to field a usable (albeit sub-optimal) LR Spitfire in 1943,
and the things which I believe would have been affected by any
prioritisation would have been the F.21 and the Seafire. It was all
just a question of priority.

No question about it.

See my comments on Spit V Cg problems above. In 1943, with lots of Mk. IXs not
able to do much, I think the effort needed to go there or into the Mk. VIII.

Ideally, yes. But I suggest we have to work closely within the
context of what was likely given the RAF's preconceptions and
requirements at the time. Frankly, I think no LR escort force was
going to impinge upon new production Mk IX supply until the concept
had been proven. Hence the movement of the existing Vc force in 12
Group (which did historical do USAAF daylight escorting) into an LR
mode.

RAF Spits had been escorting U.S. a/c from 1942, so IMO there was no question as to
operational utility, just a question of priority.


The
Spit V was just too inferior at B-17/24 heights, even assuming it could carry the
fuel (better than nothing, I grant you, but I expect fighter squadron morale
would have been the pits).

The key here is having the Vs unshackled from their range limitations.
They were not the best escorts, but they would have been the most
likely to be available. There's no question in my mind that VIIIs/IXs
or even P-47s would have been better. But a 1943 LR effort was not
going to suffer the same critical limitations the RAF and the Spitfire
V force endured over the Pas de Calais in 1941-42, in terms of
operational scope and endurance. Actually escorting a bomber force
the Germans were compelled to consider attacking would have been a
major advantage by itself. The tactical background was going to be
different, and more in their favour, than it was over the Channel on
short-range operations. As it was, in the summer of 1943 the V force
operating over Holland with Vs don't seem to have been demoralised. I
tend to be a little sceptical of Caldwellesque claims in this respect.

They were still in for a hard time, though, I agree. But as a
component part of a diffuse deep-penetration escort, they wouldn't be
carrying the burden alone. And most of all, the Luftwaffe wouldn't
have the freedom to avoid engagement en masse whenever they couldn't
get the tactical advantage, as they could with shorter-ranged Circus
operations.

Good points, and I don't disagree about the utility of the Mk. V as 'certainly better
than nothing,' and better to lose people one at a time rather 7 or 8 at a time Again,
my main concern with the V is whether they could in fact have been given the radius
(not range).

snip various areas of agreement

AOC 12 Group: "Clearly other commands want the LR Spitfire as well.
I suggest the VCAS recommends increased tankage production and the MAP
is instructed accordingly."

And that's what we planned to push for: Mk. VIIIs or Mk. IXs with VIII tanks,
plus whatever extra fuel Supermarine could make work until the Mustangs were
available in sufficient numbers. Ideally, we wanted the Mk. XVI a year earlier.

I don't think the early XVIs actually had the rear-fuselage tankage
when they first came off the production lines (September 1944),

Right, I should have said the rear fuselage tank (and I think they only came in with
the cut-down rear fuselage) about 16-18 months early, as i forget just when those
versions came out, but I think it was only in '45.

but I
think the main reason the tanks didn't appear earlier has far more to
do with institutional preconceptions than the real engineering
problems involved. When it comes to it, if we push the tankage issue
for Spits, there's no reason for them to delete the rear-fuselage
tanks in their Mustangs, either.

Well, if they didn't need them for their own purposes, why carry the weight around?

snip more agreement

Just my opinion, though.

Agrees with our reasoning exactly, with the reservations stated re the Mk. V.

Please desist from this moderate rationality or I will complain to
your ISP.

Did I mention that I have INCONTROVERTIBLE PROOF that the U.K. government has been
testing UFOs ( and dissecting ALIEN CORPSES) at their base at Machrihanish, cleverly
disguising test flights of same as those by Aurora and, in times past, SR-71s? Wait,
I hear the black helicopters coming to get me. I can feel the beams as they try to
alter my brain. Excuse me while I done my tinfoil hat.

Guy

The Revolution Will Not Be Televised wrote:

On Sat, 09 Aug 2003 07:52:50 GMT, Guy Alcala
wrote:

[snip unacceptable tirade of rational discourse]

[3 Group flying B-24s]

Remember, though, that the U.S. phased out B-24 production at 3 of the 5 factories
making them (Douglas Tulsa, Convair Fort Worth, and North American in Dallas) during
1944, as Ford and Consolidated San Diego were able to produce sufficient numbers for U.S.
requirements. Even so, according to Joe Baugher's website the RAF received 1,600 B-24H, J
and Ls between Spring '44 and August '45, so there was clearly excess capacity
available.

OK, I can accept the increased B-24 availability in 1944, but what do
we lose as a consequence, and what do we do in 1943 meanwhile?

The RAF loses very little. The USAAF slows down the formation of B-24 groups slightly, but
mainly doesn't need to cut training time for its heavy crews owing to high loss rates, as the
RAF crews will be taking up much of the slack.

They had some in East Anglia, and could be allocated more. Just like
3 Group (and 8 Group), they were adjacent to USAAF bases, so the fuel
pipeline and rail links would have been available.

I was thinking more of runway/taxiway/ hardstand length and strength, as well as hangar
size, bomb dumps, accomodations etc. All would likely need upgrading.

They'd just re-allocate the bases to the relevant groups. Swap a
grass strip for an asphalt one in another Group. I don't think it's a
major issue.

Not quite that simple, if you want to base them close to the U.S. daytime units. Who's going
to use the grass strips 2 Gp. would be giving up? The heavies aren't.

I think the B-25
is a contender he it had the range for shallow penetration raids
to the Ruhr, reasonable defensive armament and a good bombload. I
suggest phasing out the Boston in 2 Group and replacing it with the
Mitchell, and using the six to eight squadrons in 2 Group for daylight
strategic bombing. Further expansion could follow if the aircraft
were available.

Nah, same limitations of range and ceiling as the B-26s, with a smaller bombload.

Really? I thought it had a better range and bombload, but I'm no
expert.

Slightly (but not significant in a tactical sense) better range, but only 3,000 lb. vs. 4,000
lb. bombload. Going into the Ruhr by day in 1943/early '44 at 10-15,000 feet (vs. the 20,000
feet plus of the heavies) would be a 'really bad idea' (tm).

I saw it fulfilling a diversionary/supporting role, hitting
airfields and less-heavily defended targets outside the major heavy
Flak belts and giving the Luftwaffe controllers headaches trying to
identify the main raiding force formations. In other words, doing for
the B-24s in 3 Group what the 2nd Bomb Division B-24s did for the
B-17s in the rest of the 8th AF historically at this point.

The mediums were doing what you say, but at shorter ranges, and there was never much doubt by
the Luftwaffe who they were owing to the very different cruise and bombing altitudes.

Hell,
the mediums were operating down below Stirling height (both the R-2600s in the B-25 and
the R-2800s in the B-26 had single-stage two-speed supercharging, optimized for about
15,000 feet) which is okay for relatively lightly defended tactical targets but a really
bad idea going after German industrial targets. If they wanted to go to Germany from
England it had to be with heavies, or the unavailable in sufficient numbers Mossie.

The tactical bombers had to face the Flak when operating over western
Germany in 1945, and it was suvivable given adequate support and
decent planning.

In 1945, when much of the defense was in a state approaching collapse, and where our airpower
was overwhelming.

And many of the tactical targets they did hit had
substantive flak defence (albeit nowhere near 1943 Ruhr levels, let
alone 1945 Politz levels). Even so, I wouldn't suggest using them as
a deep-penetration strategic force.

Seems we agree on that, then.


Well, if it would help get things back to normal around here, whenever one of us chooses
to present and discuss factual data that contradicts hoary old myth and one-sided
perceptions, the other could accuse him of belittling the accomplishments, bravery and/or
importance of various aircrew nationalities/theaters/periods.

At last, a contribution in this thread which reaches beyond
rationality to advocate a return to the traditional and time-honoured
mode of usenet discourse.

How much civil discussion,
analysis and argument can r.a.m. stand? ;-)

Of course, the key difference between a USAAF daylight strategic
bombing effort and an RAF one would be the greater efficiency of the
latter. I mean, once we factor out all those ludicrous PX
requirements for Coca-Cola, ice-cream and signed movie star's
underwear, we should free up about 50% extra import capacity for bombs
and replacement aircraft.....

Ha! And if we could eliminate all the manhours lost/opportunites missed to morning and
afternoon tea/brewing up, we could have won the war in 1944 at the latest;-)

Guy

I've been delayed my own self, but I'll invite myself back in...

In article ,
(The Revolution Will Not Be Televised) writes:
On Sat, 09 Aug 2003 18:50:48 GMT, Guy Alcala
wrote:

[snip isolated points of contention in a torrent of otherwise
dispicably rational discussion and nauseating agreement]

[rear fuselage tanks in Spit Vcs]

I think you may be underestimating the difficulty re the Mk V. Quill, in His
"Spitfi A Test Pilot's Story," devotes an entire chapter to "Longitudinal
Stability and Increased Range."

Yes, but a close reading of that source and others leads me to the
conclusions which follow.

He describes the weight additions and Cg
problems that led to the installation of bobweights on the Mk. Vs, as well as the
first fitting of a 75 gallon tank to a Mk. IX (ML 186), which he flew from
Salisbury Plain to the Moray Firth and back at low altitude and economical cruise
-- this a/c had a bob-weight in the elevator system plus an enlarged horn
balance. Quill writes that "the aeroplane was unstable to start with but as soon
as I had used up the rear fuselage fuel the handling was back to normal . . ."

Precisely the same condition as experienced with the rear fuselage
tank in the P-51B. I'll admit upfront that the CoG issues with the
Spit Vc/IX airframe were more serious, but this was not a binary
issue: it came down to what level of initial instability with a full
rear tank the institution concerned was prepared to tolerate.

I have to respectfully disagree. I took some time to dig up figures
on the CG range of various model Spitfires and U.S. fighters.
Sources, in this case being A&AEE Reports in the case of the Spits and
the Mustang I, and U.S. Federal Aviation Agency Type Certificate Data
Sheets for the others.

The Spit, especially the small tailed Mk V, had a very narrow CG
range. Something on the order of 1.6". The later aircraft, both the
2-stage Merlin powered VIII, IX, and XVIs, and the various Griffon
models, also had a narrow range, but had the advantage of a heavier
engine way up front to even things out. It'a also teh case that
retracting the gear on a Spit translated the CG aft nearly half of its
range. That's teh problem with dainty little airplanes - it doesn't
take much to upset 'em.

In contrast, a P-51A has a CG range of 5.4", and a B has a CG range of
a bit over 7". Witn no noticable CG shift gear up or down.
A Spit, loaded to, or just beyond the aft CG limit is going to be
displaying a really nasty pitchup just after takeoff when the gear
comes up. It couldn't come at a worse time.
Other U.S. fighters that I could dig up in short order are the P-40,
with a CG range of 8.9", and the P-63 with a range of 5.4". On first
analysis, stuffing an aft fuel tank into a Spit V is a much more dicey
proposition that doing the same with a P-51.

Actually, if you're looking for a fairly long-ranged Medium/Low
altitude escort fighter already in RAF hands in 1942, might I suggest
the Allison-engined Mustang I, IA and II. They're long legged, adn
while they don't climb as well as a normally loaded Spit V, they're
danged fast, accelerate well, and can meet an Fw 190A on fairly equal
terms. Mustang Is were the first RAF fighters over Germany, after teh
fall of France, and they spent a lot of time stooging around in the
same areas that are being proposed as Medium Bomber targets.

I suggest, on the balance of evidence I've seen (which I admit is not
comprehensive), the RAF were far more sensitive to this than the USAAF
was. A case in point is the rear fusleage tank in the P-51B/Mustang
III. The instability caused by a full 85-gallon rear fuselage tank
was no different between Mustangs in RAF colours and those in USAAF
colours, the critical difference was the institutional appreciation
involved, which saw the RAF delete it entirely while the USAAF adopted
it happily. I suggest that the USAAF approach to rear-fuselage tanks
was materially different, and a similar need for long-range escorts
for a daylight strategic bombing strategy on the part of the RAF would
have entailed a similar approach as the USAAF adopted: i.e. the
instability would have been accepted in order to achieve the desired
operational aim.

Perhaps. It's also the case that the RAF were never really in the
Long Range Escort business. Most of their missions didn't require
flying Combat Air Patrols over German airfields near Prague. The aft
fuel tank didn't provide a whole lof of gain for the RAF.

I won't go into the institutional differences in detail here, but the
whole counter-factual only works if we adopt a USAAF-like commitment
to daylight strategic bombing. Absent that commitment, with all that
it entailed in terms of forcing long-range escort capacity regardless
of the difficulties (such as CoG issues with increased internal
tankage), and there wouldn't be any RAF daylight bombing effort to
start with. Without one, the other does not follow, but if we're
positing the first, we need to accept that this would modifiy
historical RAF fighter procurement and equipment beyond the historical
norm. In short, attitudes to things like the acceptable level of
temporary instability in a Spitfire with full rear-fuselage tanks
would have to change.

Just my opinion, mind, but I think the thing that really would have
crimped an RAF long range day bombing effort would have been pilot
availability. The RAF Night Heavies (Except, I think, for the
Sirling), were 1 pilot airplanes. That's not enough if you expect to
be getting shot at by people wh actually can see what they're shooting
at. You're going to want copilots, and where are you going to get
them? The Empire Air Training Scheme was a tremendous achievement,
but it was pretty stretched supplying the pilots that the RAF needed
in real life. And you'll have to divert even more pilots to be
instructors.


While he and Joe Smith felt that some longitudinal instability at the start of
the flight was acceptable (as with the Mustang), the margins seem to have been
much smaller in the case of the Spit. The Mustang's stability was judged
acceptable once the rear tank was down to somewhere between 25 and 50% (opinions
differ),

Much like the behaviour of the actual Mk IX/XVIs with rear-fuselage
tanks in 1945.

and if you want to extend the escort range it's the amount of fuel you
can carry internally to fight and return on that determines escort radius, no
matter how much fuel you hang externally to boost endurance.

Agreed. This is why the rear-fuselage tankage issue is critical to
this speculation.

They key difference between the Mustang and the Spitfire here, I
suggest, is institutional, and not just a matter of engineering. The
two Mk IXs with internal capacity enlarged by Wright Field at the same
time (July 1944) are a similar example: the RAF turned them down,
while the USAAF were clearly prepared to tolerate engineering
trade-offs (such as changes to the wing structure) that the RAF
wasn't. I suggest this gives us an indication of the approach
differential involved on an institutional basis which transcends the
engineering problems.

Again, I must disagree. The cold, hard numbers say that the Spit was
a lot less tolerant of stuffing weight behind the wings. It's
intersting to note that the Wright Field modified Spits got a big
chunk of their extra capacity by stuffing fuel into the wing leading
edges, which not only didn't upset the CG as much, but moved it in the
forward (good) direction, somewhat counterbalancing the tank behind
the cockpit.

I fully accept that the Spit had less CoG margins to play with, but I
still believe the required engineering solutions were at hand. On a
chronological basis, the bob-weight issue first came into focus when
Tony Bartley returned to operations with 65 Squadron after a spell
working under Quill as a test pilot at Supermarine, in February 1942
(as mentioned in the memoirs of Quill, Bartley and the other flight
commander in 65 Sqn at the time, Geoff Wellum).

Much less, according to the reports. To increase the CG range of a Mk
V enough to fit a rear tank, you'll need a bigger tail, and ballast in
the nose. At that point, it stops being a Field Conversion, and
starts looking like a remanufacturing job.

I'm happy to accept that the Vc would have had proportionately more
CoG problems than the Mustang, but the overall problem seems
identical. Allowing for some flexibility in terms of the final
compromise (maybe a tank size between the 29-gallon ferry tank of 1942
and the 75-gallon rear tank of 1945) would seem reasonable, but
dismissing the option altogether goes too far, I think. Operational
neccessity was a powerful advocate. Absent the need to escort their
own bombers in long-range daylight raids, the RAF had no need to
pursue the issue with the same vigour and tolerance for compromises
that the USAAF had, so I don't think we can take their historical
behaviour absent this need in the first place as the ultimate
determinant factor when we speculate on their behaviour in a scenario
where this factor exists.

If I get a chance, I'll run some numbers for how much fuel it would
take to get a Spit V to its rear limit. At a first guess, I'd say
"Not Much". The rearward shift when the gear comes up is a problem.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

Alan Minyard wrote:

: Actually, the death knell was sounded by the P-80 and the Meteor. They
: were developed into the future of aviation, while the Me-262 was a
: dead end project.

: Al Minyard

Hi Al,

Not arguing with you, but I'd be curious to know what rationale you
use to arrive at the conclusion that the ME-262 was a dead end
project.



--- Gregg
"Improvise, adapt, overcome."

Smithsonian Center for Astrophysics
Phone: (617) 496-1558

"Gregg Germain" wrote in message
...
Alan Minyard wrote:

: Actually, the death knell was sounded by the P-80 and the Meteor. They
: were developed into the future of aviation, while the Me-262 was a
: dead end project.

: Al Minyard

Hi Al,

Not arguing with you, but I'd be curious to know what rationale you
use to arrive at the conclusion that the ME-262 was a dead end
project.



--- Gregg

Has there been a follow-on project?

Tex

On Tue, 26 Aug 2003, Tex Houston wrote:

"Gregg Germain" wrote in message
...
Alan Minyard wrote:

: Actually, the death knell was sounded by the P-80 and the Meteor. They
: were developed into the future of aviation, while the Me-262 was a
: dead end project.

Hi Al,

Not arguing with you, but I'd be curious to know what rationale you
use to arrive at the conclusion that the ME-262 was a dead end
project.

Has there been a follow-on project?

Soviet Sukhoi Su-9 and Su-11.

Japanese Nakajima "Kikka".

Arguably, the Czech S.92.

Cheers and all,

"Tex Houston" wrote in message
...

"Bill Shatzer" wrote in message
...
Has there been a follow-on project?

Soviet Sukhoi Su-9 and Su-11.

Japanese Nakajima "Kikka".

Arguably, the Czech S.92.

Cheers and all,

Gee, none of these sound like a German aircraft. Oh, well.


Well the Germans were rather discouraged from building new
jet fighters between 1945 and the mid-50's

Keith

"Emmanuel Gustin" wrote in message ...
"Tex Houston" wrote in message
...

Has there been a follow-on project?

Gee, none of these sound like a German aircraft. Oh, well.

Messerschmitt jet design followed several tracks. One track
was the development of the 'HG' (Hochgeschwindigkeit, high
speed) versions of the basic Me 262. These involved sweeping
back the wings and tail to get a better transsonic performance,
and,

in the HG III project, moving the engine nacelles to the
wing roots.

The HG III used He S11 engines which I believe would have better
resistence to turbulent flows. This was meant to be the original
position.


These designs were intended as heavy fighters or nightfighters.

The more important, for in the long term much more influential,
development track was the P.1101 series. These were swept-wing
jet fighters from start, and directly provided the inspiration for
post-war designs such as the F-86 Sabre. (The P.1101 looked
like a cross between a Sabre and a Saab J29.)

As far as I know the Me 262 HG design never got beyond the
wind tunnel stage, while metal was cut on the P.1101 projects.
(The P.1101 development aircraft was constructed and shipped
to the USA after the war; Bell derived the variable-sweep X-5
from it.) So in practical terms the Me 262 was not a basis for
significant further development; the Germans did not have the
resources left to build the Me 262 HG designs anyway. The
German influence on post-war jet fighter design was very great,
but it came from the more advanced Messerschmitt and
Focke-Wulf projects, not from the Me 262.

But the Me 262 was not any more a 'dead end' than the Meteor
or the P-80. The first jet fighters were simply a poor basis for
further development, because new aerodynamic concepts were
imposing themselves. The design teams did try, of course, but it
was much better to start with a clean sheet of paper. The exception
was the F-97, aka F-94C, which was derived from the basic
F-80/F-94 design as a stopgap nightfighter, and for which speed
of development was the overriding factor.


The Arado 234 is often neglected. The 4 engined (BMW 003) Arado 234C
was easily the fastest jet of WW2 (3 entered troop testing I believe)
at some 568 mph. (this was mach limited: the aircraft could excede
its own mach limit in level flight!)

It's designer Kosin (first name Rainer I think) came up with the idea
of lofting the Ar 234 wing on a computer to join rivets and spars at
points of equal curvature instead of equal chord. This produced an
incredubly smooth surface that is essential in high speed aircraft
swept wings or not. This method was orderd to be studied by the
other German designers.

The 4 engined Ar 234C also had the first modular engine installation.

Kosins reasearch also influenced the double delta seen on the RAAFs
Victor bomber.

Also quite influencial were the German Jet engine designers such as
Franz Anselm (designer of the Me 262a Jumo 004 and T53 for Allison,
Pabst von Ohain Himself and Max Bentley.

The term "after burner" is a derivative of the german "nach-brenner".
The British still often use their own term "reheat". I believe the
jumo 004E was the first afterburning engine to run.

On 26 Aug 2003 14:26:00 -0400, Gregg Germain
wrote:

Alan Minyard wrote:

: Actually, the death knell was sounded by the P-80 and the Meteor. They
: were developed into the future of aviation, while the Me-262 was a
: dead end project.

: Al Minyard

Hi Al,

Not arguing with you, but I'd be curious to know what rationale you
use to arrive at the conclusion that the ME-262 was a dead end
project.



--- Gregg
"Improvise, adapt, overcome."

Smithsonian Center for Astrophysics
Phone: (617) 496-1558

The fact that there were no follow on aircraft. Of course the fact
that Germany lost the war was a major factor in this, but it is still
a fact. The 262 was the first and last jet fighter of its linage.

Al Minyard

The Kikka was a copy, not a follow on, and very few were produced. The
Sukhoi SU-9 was a single engine, delta wing design in no way related
to the 262, while I fail to see any relationship of the SU-11 to the
Me.

Al, there was an earlier Sukhoi with the same designation that was scotched by
Stalin personally, as he was convinced it was nothing more than a 262 copy
(which it was).

I am unfamiliar with the S.92, and I cannot find it in any of my
references or Google. Please let me know where I can research it.

Its a Czech version of the 262. The Nazis built some of their 262s in
waldwerks and in other out of the way places, distributing production to escape
Allied bombing (didn't work, btw - quality control was absolutely awful and
many of these a/c were "completed" but never flew). Towards the end, the trend
was reversed and gigantic, protected shelters were built to house factories
underground - made no difference of course, there were means available to
penetrate such structures as Kahla, etc.

At any rate, some of the production was shifted to Czechoslovakia and when the
curtain fell on Hitler's insane 15 minutes of fame, the Czechs found themselves
with a country littered with Nazi hardware and small production facilities.
Included in this bonanza were production lines for the 262, as well as quite a
few examples and piles of spares. These parts were assembled postwar into the
CS 92 (2-seater equating to the Me 262 B-1a dual control trainer - NOT a
nightfighter as some think) and the S-92 singleseat nightfighter. Before you
correct me as to its status as a 'follow on', I wouldn't suggest that it was -
these were essentially parts-birds. Two examples remain at the Kbely aviation
museum, I believe.

Getting back to the earlier "262-ski" built by the Soviets - it was absolutely
a follow on, albeit short lived. I think the role of the Me 262 in history was
to act as a dividing line between prop fighter supremacy and the rise of the
jet. General Arnold agreed with this and made remarks that "We were really
lucky, weren't we?", when he was given an 'airshow' with a captured example.

v/r

Gordon
====(A+C====
USN SAR Aircrew

"Got anything on your radar, SENSO?"
"Nothing but my forehead, sir."