#1 Jet of World War II

On Wed, 23 Jul 2003 14:00:12 +0100, John Halliwell
wrote:

The crucial point though, is that you're assuming the Lanc would have to
follow US practises and fly in the big box formations.

Standard RAF practice was to tighen up daylight formations around
three-plane elements in vics. This was not as tight as a USAAF combat
box, but under a heavier fighter threat it probably would have evolved
further in that direction.

Whilst this may
have suited the B-17 with machine guns sprouting everywhere (although I
don't think it was appropriate before P-51D escorts were available), it
may not have suited the Lanc. You simply can't enforce US practises on
UK types in an attempt to 'equate' them with one another.

Close formation flying both increased the concentration of the bomb
pattern and the effectiveness of return fire from the gunners. The
RAF were extolling this in 1939 with Wellingtons over Heligoland
Bight, and continued to do so in "large-scale" daylight ops (e.g. the
Lancasters in the Augsburg raid).

One Halifax squadron removed the nose and mid-upper turrets, armour,
flame dampers and various other bits, the lighter weight and less
restricted engines flew higher, faster and their losses were reduced
significantly.

This works at night, where difficulty of interception is the primary
defence. It would have been a lot less effective when some measure of
resiliance and defensive capacity was required, which is why the RAF
stuck self-sealing tanks, protective armour and increased armament on
their bombers after their daylight experiences in 1939. Increasing
height and cruising speed at night made it harder for night-fighters
with a marginal performance advantage to achieve an interception,
particularly within a context where there were easier targets at
slower speeds and lower height to engage first. The same dynamic
doesn't neccessarily apply in daytime, in fact loose formations and
seperation from the main body positively attract enemy fighter
attention in those circumstances.

Gavin Bailey
--

"...this level of misinformation suggests some Americans may be
avoiding having an experience of cognitive dissonance."
- 'Poll shows errors in beliefs on Iraq, 9/11'
The Charlotte Observer, 20th June 2003

"The Revolution Will Not Be Televised" wrote in
message ...
On Wed, 23 Jul 2003 14:00:12 +0100, John Halliwell
wrote:

The crucial point though, is that you're assuming the Lanc would have to
follow US practises and fly in the big box formations.

Standard RAF practice was to tighen up daylight formations around
three-plane elements in vics. This was not as tight as a USAAF combat
box, but under a heavier fighter threat it probably would have evolved
further in that direction.


More likely reverted to night bombing. Without air superiorty
over the target daylight bombing created too many losses.

Whilst this may
have suited the B-17 with machine guns sprouting everywhere (although I
don't think it was appropriate before P-51D escorts were available), it
may not have suited the Lanc. You simply can't enforce US practises on
UK types in an attempt to 'equate' them with one another.

Close formation flying both increased the concentration of the bomb
pattern and the effectiveness of return fire from the gunners. The
RAF were extolling this in 1939 with Wellingtons over Heligoland
Bight, and continued to do so in "large-scale" daylight ops (e.g. the
Lancasters in the Augsburg raid).



Which were unmitigated disasters. The Heligoland raid had 50%
losses and during the Augsburg raid 97 squadron lost 7 out of 12
aircraft. Bottom line is the .303 was worfully inadequate against
fighters armed with 20 and 30 mm cannon and unescorted daylight
raids were unsustainable.

One Halifax squadron removed the nose and mid-upper turrets, armour,
flame dampers and various other bits, the lighter weight and less
restricted engines flew higher, faster and their losses were reduced
significantly.

This works at night, where difficulty of interception is the primary
defence. It would have been a lot less effective when some measure of
resiliance and defensive capacity was required, which is why the RAF
stuck self-sealing tanks, protective armour and increased armament on
their bombers after their daylight experiences in 1939. Increasing
height and cruising speed at night made it harder for night-fighters
with a marginal performance advantage to achieve an interception,
particularly within a context where there were easier targets at
slower speeds and lower height to engage first. The same dynamic
doesn't neccessarily apply in daytime, in fact loose formations and
seperation from the main body positively attract enemy fighter
attention in those circumstances.


Sure but as both the USAAF and RAF learned the hard way
tdeep penetration daylight raids were NOT sustainable without
fighter escort. Once air superiority had been gained the major risk
came from flak and in that case a tight formation may be a liability

ISTR that during late 44/45 daylight raids 617 squadron deliberately
flew in loose gaggle of aircraft rather than a tight box as this presented
a more dispersed target for the flak.

Keith

On Wed, 23 Jul 2003 15:35:11 +0100, "Keith Willshaw"
wrote:

Standard RAF practice was to tighen up daylight formations around
three-plane elements in vics. This was not as tight as a USAAF combat
box, but under a heavier fighter threat it probably would have evolved
further in that direction.

More likely reverted to night bombing.

Of course.

Without air superiorty
over the target daylight bombing created too many losses.

No disagreement here.

Close formation flying both increased the concentration of the bomb
pattern and the effectiveness of return fire from the gunners. The
RAF were extolling this in 1939 with Wellingtons over Heligoland
Bight, and continued to do so in "large-scale" daylight ops (e.g. the
Lancasters in the Augsburg raid).

Which were unmitigated disasters.

Of course they were. The point is that the RAF when flying in
daylight, did rely on some extent to formation flying and gun defence.
This was known to be inadequate in the absence of air superiority, and
I'm not claiming otherwise.

The Heligoland raid had 50%
losses and during the Augsburg raid 97 squadron lost 7 out of 12
aircraft. Bottom line is the .303 was worfully inadequate against
fighters armed with 20 and 30 mm cannon and unescorted daylight
raids were unsustainable.

The .5in-armed B-17's suffered from the same dynamic. Given the
ranges at night were generally closer, the .303s were more effective
as a night defensive armament than by day. Even so, the main value of
a night bomber gunner was as a lookout to initiate evasive action.

Sure but as both the USAAF and RAF learned the hard way
tdeep penetration daylight raids were NOT sustainable without
fighter escort.

Of course not, and I'm not contending otherwise. I'm just pointing
out how the late-war Lanc family evolved in the operational climate of
1944-45, which was permissive enough to allow daylight bombing to be
resumed and a certain level of adaption for that role in terms of
aircraft equipment to be utilised.

ISTR that during late 44/45 daylight raids 617 squadron deliberately
flew in loose gaggle of aircraft rather than a tight box as this presented
a more dispersed target for the flak.

Formation flying in fully-laden B.1S Lancs was never a practicable
proposition - there was almost no margin of available power in hand
for formating.

Gavin Bailey

--

"...this level of misinformation suggests some Americans may be
avoiding having an experience of cognitive dissonance."
- 'Poll shows errors in beliefs on Iraq, 9/11'
The Charlotte Observer, 20th June 2003

John Halliwell wrote:

In article , Guy Alcala
writes
In short, design and equip them
to do the same job and they'll do it with payloads within a couple of hundred
pounds (either way) of each other. The whole Lanc vs. B-17 argument is just
ludicrous.

The crucial point though, is that you're assuming the Lanc would have to
follow US practises and fly in the big box formations.

No, I'm saying that _if_ you followed US practises etc., the Lanc's performance
would be within a few % either way of the B-17's. Nowhere did I say that you had
to do so, but that is the variable that is always left out of the Lanc vs. B-17
threads, so that they wind up comparing apples and oranges.

Whilst this may
have suited the B-17 with machine guns sprouting everywhere (although I
don't think it was appropriate before P-51D escorts were available), it
may not have suited the Lanc. You simply can't enforce US practises on
UK types in an attempt to 'equate' them with one another.

See above.

One Halifax squadron removed the nose and mid-upper turrets, armour,
flame dampers and various other bits, the lighter weight and less
restricted engines flew higher, faster and their losses were reduced
significantly.

And so did B-17 and B-24 groups operating by day at various times and places, and
that's my point - it's ludicrous to compare two aircraft designed and equipped for
totally different missions and claim that one is "superior" to the other, by
looking _only_ at the mission for which one of them is optimised. In the B-17 vs.
Lanc argument, this method is routinely used to 'prove' that the Lanc had a better
payload/radius than the B-17, by comparing the Lanc's performance operating singly
at night, with the B-17's performance operating in formation by day at higher
altitudes. Basing a conclusion on such an 'analysis' is a prime example of GIGO.

Guy

In article , Guy Alcala
writes
No, I'm saying that _if_ you followed US practises etc., the Lanc's performance
would be within a few % either way of the B-17's.

But why drag the performance of an aircraft down by using it in a way
that is clearly inefficient? All this discussion has confirmed to me is
how inefficient the big box formations actually were. Dragging the
performance of a heavy bomber down to the point where it is carrying a
similar load to a Mossie, whilst remaining considerably vulnerable (and
with a crew of ten), doesn't make much sense to me.

A couple of Mossies with a light load, perhaps 2,000lbs each start to
sound more and more promising. Small, fast formations may have been very
effective.

Nowhere did I say that you
had
to do so, but that is the variable that is always left out of the Lanc vs. B-17
threads, so that they wind up comparing apples and oranges.

The B-17 bomb bay was not the best arrangement for carrying large loads.
As such had it been used in night ops, the range/payload may not have
been able to be improved to compensate for lighter fuel (or fewer
guns/crew) loads. On that basis, it's easier to drag the Lanc down by
hampering it with US practises than boost the B-17 by using RAF
practises.

--
John

John Halliwell wrote:

In article , Guy Alcala
writes
No, I'm saying that _if_ you followed US practises etc., the Lanc's performance
would be within a few % either way of the B-17's.

But why drag the performance of an aircraft down by using it in a way
that is clearly inefficient? All this discussion has confirmed to me is
how inefficient the big box formations actually were. Dragging the
performance of a heavy bomber down to the point where it is carrying a
similar load to a Mossie, whilst remaining considerably vulnerable (and
with a crew of ten), doesn't make much sense to me.

Who says it was inefficient, under the prevailing circumstances? Clearly, the RAF
heavies would have suffered much heavier losses than U.S. heavies if they had tried
to operate by day, in formation, in the same time frame (especially before air
superiority had been won). Out of formation, they would have been slaughtered on an
even more routine basis than the U.S. heavies were, because they had no effective
daytime defensive armament, lacked armor, altitude performance, co-pilots etc. etc.
And they would have been knocked out of formation much more easily, lacking all the
above.

A couple of Mossies with a light load, perhaps 2,000lbs each start to
sound more and more promising. Small, fast formations may have been very
effective.

Small 'formations' for point targets, sure. For large industrial targets covered by
smoke and clouds, almost certainly not. A Mossie could carry at most 6 x 500 lb.
bombs (2 external), while a B-17 could carry twice that internally, i.e triple the
bmb load you recommend. If the Mossie's extra speed prevents more intercepts and it
can bomb from a lower altitude, it may well be more efficient than carrying more
bombs and dropping from higher up, but it's by no means certain that's the case
(unlike some on the NG, I don't rule out the possibility, but the only way to find
out for sure would have been to actually try it, and that didn't happen).

Now, could a B-17's performance be improved by removing some or all of the defensive
armament? Sure, which was done starting mid-44. At first, they removed the radio
room gun and left one of the waist gunners behind; less ammo was usually carried as
well. By 1945, one combat wing ordered one of its groups to remove the ball turret
from their a/c, another group the chin turrets and the third group both waist guns
(and their gunners). A different group in '45 was given permission to remove the
chin turret, ball turret AND either both waist guns or the top turret (forget
which). It boosted cruise speed by about 25 mph, or allowed a tradeoff of fuel,
bombload, and/or height. But it was possible (and made sense to do so) because by
then the fighter threat was rapidly shrinking. Defensive armament doesn't help
against flak, which was the primary threat in that period, but speed and altitude
do.

Nowhere did I say that you
had
to do so, but that is the variable that is always left out of the Lanc vs. B-17
threads, so that they wind up comparing apples and oranges.

The B-17 bomb bay was not the best arrangement for carrying large loads.

Certainly (the same was true to a lesser extent with the B-24), but that was due to
the structural design decisions made, not an inherent effect of design for day vs.
night bombing. Just look at the B-29 and B-36. I don't know why U.S. heavy bomber
designers pre-war went for short and tall bomb bays rather than long and shallow
oones like the RAF's; FAIK it was considered to give a better bomb pattern, or maybe
there was some different reason. It certainly wasn't universal among U.S.
bomber/attack a/c, as I can attest having had to slide over the wing spar (just like
a Lanc) to go from fore to aft in a P-2 Neptune.


As such had it been used in night ops, the range/payload may not have
been able to be improved to compensate for lighter fuel (or fewer
guns/crew) loads. On that basis, it's easier to drag the Lanc down by
hampering it with US practises than boost the B-17 by using RAF
practises.

The question is, what was the typical load actually carried by Lancs? In 1943, it
was about 8,000 lb. (effective bombload was something like 7,450 lb. The difference
represents aborts and a/c shot down before bombing ). In 1944 and '45 it increased,
both because there were more short-range tactical missions (to more lightly defended
targets), the defenses were lighter, and because friendly terrain was closer
(allowing more fuel efficient flight profiles and more divert possibilities if low
on fuel, i.e. less reserve fuel needed to be carried). Can a B-17 carry 8 x 1,000
lb. bombs in the bomb bay? There seems some question about that - it could
definitely carry 6 (the B-24 could carry 8), and could carry a pair externally.
Could a British heavy carry more individually larger bombs internally? Yes (with
the possible exception of the Stirling), but again that was a design decision, not
an inherent effect of the type of bombing to be done.

Guy

"John Halliwell" wrote in message
...
In article , Guy Alcala
writes
No, I'm saying that _if_ you followed US practises etc., the Lanc's
performance
would be within a few % either way of the B-17's.

But why drag the performance of an aircraft down by using it in a way
that is clearly inefficient? All this discussion has confirmed to me is
how inefficient the big box formations actually were. Dragging the
performance of a heavy bomber down to the point where it is carrying a
similar load to a Mossie, whilst remaining considerably vulnerable (and
with a crew of ten), doesn't make much sense to me.


Its a good job they didnt do that then isnt it ?

A couple of Mossies with a light load, perhaps 2,000lbs each start to
sound more and more promising. Small, fast formations may have been very
effective.


In daylight they would have suffered excessive losses. The Mosquitoes
of Bomber Command were excellent night bombers but unless
you have long range fighter escorts they would not have survived
over Germany in 1943.

The Mosquito's that were used in daylight raids were mostly
the FB variety typically carrying 1000lb bomb loads and
making relatively shallow penetration raids into France
and the low countries


Nowhere did I say that you
had
to do so, but that is the variable that is always left out of the Lanc
vs. B-17
threads, so that they wind up comparing apples and oranges.

The B-17 bomb bay was not the best arrangement for carrying large loads.
As such had it been used in night ops, the range/payload may not have
been able to be improved to compensate for lighter fuel (or fewer
guns/crew) loads. On that basis, it's easier to drag the Lanc down by
hampering it with US practises than boost the B-17 by using RAF
practises.


Not really. Discarding the waist gunners and fairing over the positions
would have saved several hundred pounds and cruising at 30,000 ft
the B-17 would have been a tough target for German nightfighters.

Indeed bomber command used Fortress III's (B-17G) in 214
squadron in the Radio countermeasures role. Their operational loss
rate was 1.1%

Keith

In article ,
Guy Alcala writes:
John Halliwell wrote:

In article , Guy Alcala
writes
In short, design and equip them
to do the same job and they'll do it with payloads within a couple of hundred
pounds (either way) of each other. The whole Lanc vs. B-17 argument is just
ludicrous.

The crucial point though, is that you're assuming the Lanc would have to
follow US practises and fly in the big box formations.

No, I'm saying that _if_ you followed US practises etc., the Lanc's performance
would be within a few % either way of the B-17's. Nowhere did I say that you had
to do so, but that is the variable that is always left out of the Lanc vs. B-17
threads, so that they wind up comparing apples and oranges.

Whilst this may
have suited the B-17 with machine guns sprouting everywhere (although I
don't think it was appropriate before P-51D escorts were available), it
may not have suited the Lanc. You simply can't enforce US practises on
UK types in an attempt to 'equate' them with one another.


I've just come across my notes from the Day Bomber Lanc thread, and
here's some stuff that didn't make it into the thread that may be
germane to this discussion. With reference to armor weight.
Wartime Lancasters didn't have a whole lot of armor. The only armor,
in fact, was the Pilot's seatback, and a bulkhead over the main wing
spar, where it crosses the fuselage. Figure about 150# of armor.
It did have self-sealing tanks. (I don't know if it was for all
tanks, though. If not, you lose about 7% fuel capacity, and 3/4# for
every gallon protected.
U.S.A.A.F. day bombers carried armor at all crew positions, except
Bombardier 9Can't se through armor, after all) and the rule of thumb
was 100# per position, doubled in the case of the cockpit, which was
armored both to the rear, and to the front. Each oil cooler or
radiator that was armored cost 80#, Turret weights, less guns, are
about the same. A .50 cal gun weights as much as 2 .30s, so the tail
turret doesn't change, but the nose and top turrets gain 65#. A ball
turret, with guns, or its equivalent in a remotely sighted turret,
plus the extra crewman to operate it, is 1200#.

So - added weight for a day-bomber Lanc. (This will have to come out
of fuel or bombs), we'll assume similar ammunition wieghts

Armor for nose, tail, and top turrets: 300#
Armor for cockpit, pilot only 200#
Addition of lower turret 1200#
upgrade guns to .50 cal 130#
Armored Oil Coolers 320#
Armored Radiators 320#
That's a total of 2470#

Note that a co-pilot is a good thing
if adding a copilot, add 370#
(170# crewman, more armor)
Total oe 2840#

Note that that isn't adding stuff like waist guns.
THere's another area of vulnerability. Liquid-cooled engines are much
less tolerant of damage, even if teh cooling system is protected. A
single substantial hit (.50 cal & up) on the blcok of a liquid cooled
engine _will_ crack the block, causing coolant and oil leaks. The
air-cooled radials are much more tolerant of this kind of damage. You
can remove entire cylinders, and the engine may run well enough to get
home. There's a substantial extra safety margin, there.

One Halifax squadron removed the nose and mid-upper turrets, armour,
flame dampers and various other bits, the lighter weight and less
restricted engines flew higher, faster and their losses were reduced
significantly.

There's an old story we tell up here in the North Woods. Two friends
are out hiling, and they spot a very angry Black Bear. (Black Bears,
btw, while smaller than Grizzlies, are much better tree climbers.)
One hiker immediately drops his pack, and pulls out a pair of sneakers.
(Trainers, for you U.K. blokes) His companion inquires "What are you
doing? You can't outrun that bear!" The reply was "Don't have to
outrun the bear. I just have to outrun _you_!"
The point is, you want to be faster and higher than somebody else,
making _them_ the easier target.

And so did B-17 and B-24 groups operating by day at various times and places, and
that's my point - it's ludicrous to compare two aircraft designed and equipped for
totally different missions and claim that one is "superior" to the other, by
looking _only_ at the mission for which one of them is optimised. In the B-17 vs.
Lanc argument, this method is routinely used to 'prove' that the Lanc had a better
payload/radius than the B-17, by comparing the Lanc's performance operating singly
at night, with the B-17's performance operating in formation by day at higher
altitudes. Basing a conclusion on such an 'analysis' is a prime example of GIGO.

Concur.

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

Peter Stickney wrote:

snip

I've just come across my notes from the Day Bomber Lanc thread, and
here's some stuff that didn't make it into the thread that may be
germane to this discussion. With reference to armor weight.
Wartime Lancasters didn't have a whole lot of armor. The only armor,
in fact, was the Pilot's seatback, and a bulkhead over the main wing
spar, where it crosses the fuselage. Figure about 150# of armor.
It did have self-sealing tanks. (I don't know if it was for all
tanks, though. If not, you lose about 7% fuel capacity, and 3/4# for
every gallon protected.


U.S.A.A.F. day bombers carried armor at all crew positions, except
Bombardier 9Can't se through armor, after all) and the rule of thumb
was 100# per position, doubled in the case of the cockpit, which was
armored both to the rear, and to the front.

Later, they removed much of the crew armor and replaced it with flak curtains, as the
latter was considerably lighter and only slightly less effective.

Each oil cooler or
radiator that was armored cost 80#, Turret weights, less guns, are
about the same. A .50 cal gun weights as much as 2 .30s, so the tail
turret doesn't change, but the nose and top turrets gain 65#.

Mo 65 vs 24lb (some sources give 22, but that may be the fixed variety).

A ball
turret, with guns, or its equivalent in a remotely sighted turret,
plus the extra crewman to operate it, is 1200#.

So - added weight for a day-bomber Lanc. (This will have to come out
of fuel or bombs), we'll assume similar ammunition wieghts

Armor for nose, tail, and top turrets: 300#
Armor for cockpit, pilot only 200#
Addition of lower turret 1200#
upgrade guns to .50 cal 130#
Armored Oil Coolers 320#
Armored Radiators 320#
That's a total of 2470#

Note that a co-pilot is a good thing
if adding a copilot, add 370#
(170# crewman, more armor)
Total oe 2840#

And then you can add all the extra fuel for formating, close formation, climbing higher,
and hauling all of it there and back.

I've read it somewhere that the single-pilot B-25s and B-26s saved about 300 lb., but
ISTR that the inference was that this was due to the emoval of dual controls/instruments
plus the armored seat, i.e. not counting the co-pilot's weight or any other armor.
There's also some minor additional weight for the extra oxygen tanks/regulators/lines
and the intercom lines for each additional crewman. And then there's the ammo weight.
I've seen 'typical' loads quoted as 13,000 rounds for a Lanc, 6,500 rounds for a B-17.
Belted .50 cal. weighs roughly three times as much as .30 cal. For long, deep daytime
missions beyond fighter range in 1943, that 6,500 rounds might grow to 10 or even 12,000
depending on the crew's inclinations and what the pilot would allow (some crewmen were
wont to build 'cocoons' for themselves out of extra flak vests; tail gunners who did
this could cause serious Cg problems). BTW, I don't recall seeing a photo or reading
that the Brit bomber crews wore flak vests and helmets, at least by night. I imagine
they might have adopted them if they went over to day bombing, but does anyone know for
a fact?

Guy

On Wed, 23 Jul 2003 11:40:46 GMT, Guy Alcala
wrote:

[Lanc bombing height]

The most common bombing heights (excluding exceptions like the
Peenemunde raid) seem to have been around 18,000 feet.

Odd that you should mention that, as Middlebrook ("The Nuremberg Raid") says
that a/c of all the Groups on the mission (with the exception of No. 1 GP;
see below), whether Lanc or Halifax, were evenly assigned to one of four
cruise heights -- 20, 21, 22, or 23 thousand feet.

This was common practice: although I was suprised to see 3 Group
getting the lower height bands even as they started to re-equip with
Lancasters in early 1944. The raids I researched may not be
representative, however, and I think those might have included some
late Stirling raids, which would explain it, although they were
normally banded by Group and by type within that, just like the wave
timings for TOT.

As it happens, the bombing height for the crew in question varied from
aircraft to aircraft, and seemingly independent of the assigned height
bands. The highest bombing altitude recorded was 21,500 ft (30/31 Jan
44, Berlin) otherwise 20,000 -20,500 ft (27/28 Sep 43, Nuremburg; 3/4
Sep 43, Berlin) and a lot of 18,000 -19,000 ft (31 Aug/1 Sep 43,
Berlin; Munchengladbach 30/31 Sep 43, etc, etc).

In addition to the engine differences, there's the considerable difference in
fixed weights (carried both to and from the target) due to extra crew, armor,
guns, turrets etc., and the extra fuel required for formation assembly (an
extra 1/2 to 2 hours before setting out), climb to higher cruise altitude and
flying in formation (throttle jockeying).

Yeah, I've just exhumed that one myself.

[snipadoodledo]
In short, design and equip them
to do the same job and they'll do it with payloads within a couple of hundred
pounds (either way) of each other. The whole Lanc vs. B-17 argument is just
ludicrous.

Agreed. Still, it beats doing the housework.

Gavin Bailey

--

"...this level of misinformation suggests some Americans may be
avoiding having an experience of cognitive dissonance."
- 'Poll shows errors in beliefs on Iraq, 9/11'
The Charlotte Observer, 20th June 2003