Norden Bombsight
Musicman59
Allies using in its place?
Craig
William Black
> Did the USA share it with any other allies? If not, what were the
> Allies using in its place?
>
The 'Blackett, which, unlike the Norden, could be set so the bombs
hit what you aimed at...
Plus the Germans didn't pinch all the secret stuff in it in 1938...
Blackett also invented 'Operational Research' and was the bloke who said
that the UK couldn't afford to build a bomb and the information in the
MAUD report should be given to the USA, which it was...
http://en.wikipedia.org/wiki/Patrick_Blackett
--
William Black
"Any number under six"
The answer given by Englishman Richard Peeke when asked by the Duke of
Medina Sidonia how many Spanish sword and buckler men he could beat
single handed with a quarterstaff.
mike
>
> The 'Blackett, which, unlike the Norden, could be set so the bombs
> hit what you aimed at...
If it was so good, why didn't 617 Squadron use it for Tallboy drops?
They used the SABS, which was tachometric like the Norden,
and its suspiciously close relative, the Lofte 7.
None of those bombsights dealt with windsheer that occurred
between drop and impact, one of the main causes of poor results,
but only the crosswind on the bomber itself and true groundspeed
The other Mk XIV couldn't compute the crosswind at the level
the bomber was flying at, and had to be estimated by the
bombardier, and dialed in, as well as other parameters,
rather that calculated like the others.
The biggest problem with the Norden, was that the 8AF had
Toggle with Group Leader for the rest of the box, so every other
plane could had just had a release button, for all the good the
Norden did for them if the Leader's bombardier was off.
**
mike
**
William Black
> On Nov 18, 1:56 pm, William Black <william.bl...@hotmail.co.uk> wrote:
>> The 'Blackett, which, unlike the Norden, could be set so the bombs
>> hit what you aimed at...
>
> If it was so good, why didn't 617 Squadron use it for Tallboy drops?
Because it was designed to hit an area target and Tallboy wasn't...
SABS was first used by 617 Squadron in late November 1943, The Mk XIV
(Blackett) was first used over a year earlier.
Don Phillipson
news:2a261f6c-b07f-44d6...@1g2000vbm.googlegroups.com...
> Did the USA share it with any other allies? If not, what were the
> Allies using in its place?
1. Each country with its own bombing force had its own
bomb-aiming technology (all mechanical in 1939: radar
bombsights were developed during WW2.)
2. Security at the Norden production plant was imperfect:
Memory suggests at least one spy (German or Russian)
had by 1941 obtained and passed on Norden sight details.
3. In action, when bombing by day, most Norden bombsights
sat idle because of the USAAC preference for salvo bombing
by formations. Although all crews carried a trained bombardier
and bombsight, formations usually just watched the lead
aircraft of each formation and copied it, i.e. opened bomb bay
doors when he did and toggled the bomb release as soon
as the first bomb fell from the lead aircraft. This reflected:
3a. USAAC training methods over the continental USA in
clear weather and with abundant fuel. It was normal for
formations to circle for one hour or two before setting course
for the target. It took that much time to assemble formations
and correct their spacing. British and German bomber
forces did not train like this (which European weather
seldom encouraged anway.)
3b. The B17 and B24 were designed to carry the biggest
bombs of the 1930s, i.e. 500 lb. to one ton, and could not
carry larger-sized bombs. (Several European designs
notoriously the Stirling were similarly limited. The B-29,
Lancaster and Halifax were designed to carry larger bombs.)
US training doctrine thus approached "carpet bombing,"
seeking to destroy targets by a well-distributed number of
small and medium bombs -- most simply achieved by
bombing by salvo, simultaneously, in formation. If
successful, this also produces attractive photographs.
Bombing theory was (we now know) notoriously vulnerable
to prewar propaganda, such as Gen. Mitchell's spectacular
demonstration of sinking German warships (at sea but at
anchor) and RAF folklore about skilled navigation. German
bombing theory was different, viz. from 1940 relied on radio
beam navigation, requiring skill in the pilot but none in the
navigator. RAF doctrine was revolutionized by the Butt
report on bombing failures1940-41, accelerating British
research on Gee, Loran and H2S viz. semiautomatic
navigation and bomb aiming. The USAAC changed its
methods because of experience but its core doctrine was
never challenged the way the Butt report challenged
RAF beliefs about crew skill.
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)
David H Thornley
> 3b. The B17 and B24 were designed to carry the biggest
> bombs of the 1930s, i.e. 500 lb. to one ton, and could not
> carry larger-sized bombs. (Several European designs
I'm not as sure about the B-24, but the B-17 was capable
of carrying bombs up to 2000 pound size in its bomb bay,
and (for short ranges) could carry a pair of 4500-pound
bombs under its wings. They primarily carried 500-pound
bombs, but not because they couldn't carry larger.
--
David H. Thornley | If you want my opinion, ask.
da...@thornley.net | If you don't, flee.
http://www.thornley.net/~thornley/david/ | O-
Geoffrey Sinclair
news:he6jpn$3o9$1...@theodyn.ncf.ca...
> "Musicman59" <cwest...@gmail.com> wrote in message
> news:2a261f6c-b07f-44d6...@1g2000vbm.googlegroups.com...
>
>> Did the USA share it with any other allies? If not, what were the
>> Allies using in its place?
>
> 1. Each country with its own bombing force had its own
> bomb-aiming technology (all mechanical in 1939: radar
> bombsights were developed during WW2.)
> 2. Security at the Norden production plant was imperfect:
> Memory suggests at least one spy (German or Russian)
> had by 1941 obtained and passed on Norden sight details.
German.
> 3. In action, when bombing by day, most Norden bombsights
> sat idle because of the USAAC preference for salvo bombing
> by formations.
Not in the Pacific as far as I am aware, though the later B-29
strikes may have done so, but they were much smaller formations
than were in use in Europe. Also not in Europe in the early part
of the campaign. The irony is the tolerances of the Norden were
relaxed by a factor of between 5 and 6.in order to make enough,
then the biggest user, the 8th Air Force, started removing the sites,
and using toggoleers to release the bombs when the lead crew did.
The initial training in the US was the lead aircraft would sight for
range and deflection, the other aircraft would sight for range only.
This was assuming something like a three aircraft element.
This tactic upped the collision risk considerably in tight formations,
so the 8th moved to squadron leader sight for range and deflection,
element leaders would sight for range only.
As fighter opposition increased it became group leader sight
for range and deflection, squadron leaders would sight for
range only. The drop on leader doctrine became standard
in July 1943, after trials starting in March.
The early lack of pathfinder aircraft reinforced the drop on
leader approach. It took a long time for even each group to
have its trained pathfinder aircraft. As fighter opposition
declined there were opportunities to go back to more individual
aircraft doing their own aiming.
However the way the best bombardiers were chosen to man
the lead aircraft meant it turned out the group drops tended to
be more accurate. The 15th Air force disagreed with the idea
of group drops.
> Although all crews carried a trained bombardier
> and bombsight, formations usually just watched the lead
> aircraft of each formation and copied it, i.e. opened bomb bay
> doors when he did and toggled the bomb release as soon
> as the first bomb fell from the lead aircraft.
Note given the high percentage of non visual bombing and the
way bombing aids could not be fitted to all aircraft this was
going to be the release method for most attacks against targets
in Germany by the 8th Air force.
> This reflected:
> 3a. USAAC training methods over the continental USA in
> clear weather and with abundant fuel. It was normal for
> formations to circle for one hour or two before setting course
> for the target. It took that much time to assemble formations
> and correct their spacing.
Factor in the time it took for a bomb group to have all its aircraft
safely take off. How long the aircraft would have their engines
running while waiting to take off.
http://edwardgdanaii.info:8000/401st/New/history/mission_sum.asp?mid=77
> British and German bomber
> forces did not train like this (which European weather
> seldom encouraged anway.)
Actually they did for day raids, but the difference was the numbers,
the 8th Air Force was much bigger. By the time Bomber Command
started bombing Germany by day the fighter defences were weak
enough, and the targets usually shallow enough, that they did not bother
much about formations, unless using aids like GH which again was
drop on leader.
> 3b. The B17 and B24 were designed to carry the biggest
> bombs of the 1930s, i.e. 500 lb. to one ton, and could not
> carry larger-sized bombs. (Several European designs
> notoriously the Stirling were similarly limited. The B-29,
> Lancaster and Halifax were designed to carry larger bombs.)
The biggest bomb the B-17 and B-24 could carry internally
was 2,000 pounds. I have not seen a good bomb bay diagram
of the B-29 and I note the size of the nuclear weapons, but I
suspect it was also, as designed, limited to 2,000 pound bombs.
While the Halifax could carry a 4,000 pound bomb in
practise it rarely did so on operations.
> US training doctrine thus approached "carpet bombing,"
> seeking to destroy targets by a well-distributed number of
> small and medium bombs -- most simply achieved by
> bombing by salvo, simultaneously, in formation. If
> successful, this also produces attractive photographs.
Sort of, the idea of precision bombing is to hit the target, a
large factory covers a reasonable amount of space. In
reality the 8th flew large and tight formations because of
the strength of the defences, firstly the fighters but also
to saturate the ground defences near the target.
However there are trade offs, small formations tended to
be more accurate, but that meant more formations had to
fly over the target, which degraded accuracy unless the
formations were well spaced out, to allow the dust and
smoke from the earlier strikes a chance to disperse.
Of course the smaller the formations and the bigger the
gap between them the more escorts they need, or weaker
defences.
> Bombing theory was (we now know) notoriously vulnerable
> to prewar propaganda, such as Gen. Mitchell's spectacular
> demonstration of sinking German warships (at sea but at
> anchor) and RAF folklore about skilled navigation.
Plus ideas of chemical and biological warfare.
> German
> bombing theory was different, viz. from 1940 relied on radio
> beam navigation, requiring skill in the pilot but none in the
> navigator.
Not really, the radio aids were being developed as ways for
better navigation and bad weather/night bombing aids. The
preference was to bomb visually by day, the defences in the
west forced the change over the night bombing and the rapid
need to deploy the bomb aiming systems. Note there were
three radio aids, one of which was for all bombers and for
navigation, two were bombing aids, restricted to a single group
each, used as pathfinders.
A pattern the western allies would follow.
Think how few radio aids were deployed by the Luftwaffe
in the east beyond the standard radio beacons. The RAF
was quite active in jamming Luftwaffe radio systems.
> RAF doctrine was revolutionized by the Butt
> report on bombing failures1940-41, accelerating British
> research on Gee, Loran and H2S viz. semiautomatic
> navigation and bomb aiming.
GEE was already well on the way in mid 1941 but I agree
the report made it clear the bombers needed aids or the
whole idea was unworkable.
> The USAAC changed its
> methods because of experience but its core doctrine was
> never challenged the way the Butt report challenged
> RAF beliefs about crew skill.
If you mean about precision bombing ideas you are largely
correct, the defences, or their threat, played a big part in
overall bombing accuracy and bomb loads carried even
before we talk about their direct attacks on hostile aircraft.
However one of the biggest errors the USAAF made was
an assumption of how good the European weather would
be for high altitude bombing,. that threw the idea of a
sustained precision bombing campaign into doubt.
Geoffrey Sinclair
Remove the nb for email.
David H Thornley
>
> Bombing theory was (we now know) notoriously vulnerable
> to prewar propaganda,
Everybody overestimated the potential, both of their own
aircraft and their enemies'. There was also the widespread
belief that "the bomber will always get through". One of
the issues in the Munich crisis was fear of the Luftwaffe,
particularly since Hitler made it sound far larger than it
was.
Of course, prewar air power enthusiasts, like Douhet,
foresaw the use of chemical weapons in city bombing.
Factory bombing might have been far more effective if
it included not only HE but also persistent chemical
agents. Use HE to blow the roofs off, and then drop
mustard agent on factories instead of incendiaries.
such as Gen. Mitchell's spectacular
> demonstration of sinking German warships (at sea but at
> anchor)
And unmanned.
This spawned a lot of folklore on its own, which obscures
the fact that most contemporary naval officers considered
the carrier to be probably the second most important warship,
right behind the battleship.
The British were making plans to do an air strike on
the German fleet for 1919, when there'd be enough torpedo
bombers for the British carriers.
> navigation and bomb aiming. The USAAC changed its
> methods because of experience but its core doctrine was
> never challenged the way the Butt report challenged
> RAF beliefs about crew skill.
>
You could say that the USAAF changed its methods by
concluding that unescorted bomber formations wouldn't
work. Other than that, and the adaptation to European
weather, the original USAAF techniques worked well.