B-29 reset

If you have to have a defense in a bomber, I want all the overkill I can get!

I was wondering how the radar-aimed guns decided whether or not the target was friendly or hostile. I'd HATE to be in the middle of the formation and have my IFF go on the blink or get shot out in an attack ... IF they used IFF's in WWII to distinguish targets from friendlies ... that is.

I never checked into that before ...

I'm thinking it was optical and the gunner could SEE his target reflected in the sight.

GregP said:

If you have to have a defense in a bomber, I want all the overkill I can get!

I was wondering how the radar-aimed guns decided whether or not the target was friendly or hostile. I'd HATE to be in the middle of the formation and have my IFF go on the blink or get shot out in an attack ... IF they used IFF's in WWII to distinguish targets from friendlies ... that is.

I never checked into that before ...

I'm thinking it was optical and the gunner could SEE his target reflected in the sight.

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I was thinking along the lines of ditching all but the tail gun and flying higher and faster? As I see the video, the radar is for range, one of the inputs into the "computer" but for some reason it wont play anymore on this laptop here.

I would think from the footage I have seen of raids over Europe it would be easy for the guys targeting the guns to select completely different planes, just a thought.

US presidents, prone to hoof in mouth syndrome, often do not commit US military forces in the most efficient or effective way.
As part of the B-29 reset, might we deploy to the ETO instead of Asia?
After all, the agreed upon grand strategy was Germany first: https://en.wikipedia.org/wiki/Europe_first

The distances covered would be less, and the logistics of operating from the UK significantly better (B-29's would not be needed to ferry their own supplies over the highest mountain range on the planet.)

Flying higher and faster, I can only imagine Axis flak and fighters would be less effective.

As far as the B-29 in the ETO - From Wiki...

"Originally, the Army Air Forces intended the B-32 as a "fallback" design to be used only if the B-29 program fell significantly behind in its development schedule. As development of the B-32 became seriously delayed this plan became unnecessary due to the success of the B-29. Initial plans to use the B-32 to supplement the B-29 in re-equipping B-17 and B-24 groups before redeployment of the Eighth and Fifteenth Air Forces to the Pacific were stymied when only five production models had been delivered by the end of 1944, by which time full B-29 operations were underway in the Twentieth Air Force."

A couple of points on engines.

1. Aircraft diesels Were great in theory but nobody really came up with goodones. Ones that worked yes, ones that could compete with engines running on 80-87 octane gas (at least in some areas) yes.
Diesels used higher peak pressures inside the cylinders and had to be built heavier than an equivalent spark ignition engine. Once the Gas engines went to 100 octane and higher the power to weight ratio of the diesels got worse in comparison. High powered diesels would take even longer to develop than high powered gas engines. ( please look at how long it has take to come up with high powered diesel car engines)
2. The early R-3350 was quite different than the later WWII R-3350 and the Post-war R-3350s were changed quite a bit again. The R-3350 engines used in the B-29 used quite a bit of knowledge that Wright had learned working on the R-2600s so while slowing or stopping work on the R-2600 to work on the 1st R-3350 design might ave speeding things up a bit it would not have changed things by years as Wright had to learn somehow all the stuff they wound up using on both engines. For example the early engines of both types didn't use the harmonic balancers that the later engines did and there was no room inside the crankcase on the early engines for them, later engines used crankcases several inches longer.
I am not sure when Wright shifted to the "W" style sheet metal fins on the R-3350.
3. WHile the Russians did power the TU-4 with 18 cylinder radial engines it was their 4th attempt at an 18 cylinder Wright based radial and the first 3 were less than stellar successes. Not only no hope there but rather points out that an 18 cylinder is not quite as simple to make as some people think even if you have a working 14 cylinder engine using the same cylinders.
4. in the early years (1939/40/41) before 100/130 fuel the Wrights extra displacement would be seen as an advantage as neither the R-2800 or R-3350 could use the higher boost levels. Also please remember that the late war 2800hp R-2800s were basically a whole new engine with new methods of manufacture and much improved cooling ability (less cooling drag for same power), While P&W started work on this version in 1940 it didn't see service until late 1944 and planners would have had to have been fairly optimistic
to plan on this engine powering a major bomber program back in 1941/42 when factory allocations were being made.

Napier spent a lot of time and money postwar trying to get the Nomad diesel working and even after 9 years with the best of will it was a dull engine beaten by a Wright Turbo Compounf R3350 in power and economy terms.

Napier Nomad - Wikipedia, the free encyclopedia

GregP said:

I was wondering how the radar-aimed guns decided whether or not the target was friendly or hostile.

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Bomber Command's AGLT ('Village Inn') used an infra-red IFF system to discern friend from foe.

GregP said:

I was wondering how the radar-aimed guns decided whether or not the target was friendly or hostile.
I'm thinking it was optical and the gunner could SEE his target reflected in the sight.

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GregP,

I'm thinking you are right (optical sight A.K.A. Mk 1 eyeball). I do remembering reading somewhere that the P-61s shot down a friendly or two that weren't squawking friendly on their return from runs over Japan (I assume the Widow had an IFF interogator on board). The Japanese were evidently following the bombers back to Okinawa.

Cheers,
Biff

GregP said:

In practice it was very effective because the B-29's would climb higher than necessary so they could attack from a shallow dive and be at the correct altitude over target at high speed, on the order of 320+ mph. That means that most, but not all, attacks on a B-29 were from the rear ... with radar-aimed tail guns.

There was almost no way a typical Japanese fighter could make a pass and then circle around to attack a second time. If he made a head-on pass, by the time he turned 180° the B-29 was already 2 - 3 or more miles ahead and the closing speed and extra fuel wasn't sufficient for a tail chase. There were very few beam attacks on B-29's over Japan.

Had the B-29 been deployed over Europe, things might have been a bit tougher since Europe was a high-altitude war at higher speeds. But it never was deployed there except as a visiting decoy. There was at least one B-29 that made a circuit of the UK bases, probably to cause concern in Germany.

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Yes, this method of descending high-altitude attack by B-29s made life even harder for the Japanese defenders. (It also contributed to the "too fast" problem caused by the jet stream, mentioned by pbehn.) Of course the B-29 high-altitude attacks ultimately contributed almost nothing to ending the war, due to lack of suitable targets, inability to bomb accurately from that altitude, the fact that the factories being bombed had no raw materials due to effective blockade of Japan, etc. The B-29s became useful only when LeMay changed to low altitude fire bombing.

In Europe, German pilots eventually used head-on attacks as their most effective, due to high closing speed and relatively weaker forward armament in B-17s. The same would have been true with B-29s in Europe. A problem with head-on attacks, though, was that they required considerable advance warning to get into position ahead of the bombers. That warning was often not provided by the German zone-control air defense system. Furthermore, by 1944, German pilots were so inexperienced that most of them had difficulty to "join up" for a second attack, once the first pass was over. I have to think that higher speed of B-29s would have made all of these problems more serious for the defenders. (Wikipedia lists the cruise speeds as 182 knots for B-17, 190 knots for B-29, but this does not match what I remember from reading memoirs. Of course actual cruise speed depends on load and altitude. )

Wait...what??

If you do some research, you'll find that the Japanese were quite capable of employing head on attacks against the B-29 over Japan.
The Germans were using the head on attacks successfully to the point that the chin turret was introduced (late B-17F onward) to try and ward off such attacks.

In 1944, the attacks on the bombers were anything but amateur attempts and multiple passes were the norm. Perhaps read some B-17 crew memoirs on how savage the attacks were, by Luftwaffe interceptors...or perhaps read some Luftwaffe pilot memoirs on how they employed their attacks.

Any inexperienced pilots were told to stick the Rotte leader and follow through with them...they weren't allowed to just wander around up there.

Over Japan the B-29's were not operating at cruise speed. They cruised to the target area and accelerated to "attack speed" which was usually between 290 and 335 mph or more depending on the shallow dive. Once out of local fighter range, they decelerated back to cruise speed to the flight home.

The B-17's in Europe never, apparently, tried that tactic. Perhaps the smaller B-29 formation made it possible. It would have been very dangerous to try coordinating a uniform acceleration and dive for several hundred or more bombers.

GregP said:

Over Japan the B-29's were not operating at cruise speed. They cruised to the target area and accelerated to "attack speed" which was usually between 290 and 335 mph or more depending on the shallow dive. Once out of local fighter range, they decelerated back to cruise speed to the flight home.

The B-17's in Europe never, apparently, tried that tactic. Perhaps the smaller B-29 formation made it possible. It would have been very dangerous to try coordinating a uniform acceleration and dive for several hundred or more bombers.

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I think that depends on the mission. It they were bombing at altitude using a bombsight they were flying about 210 mph.

http://www.ww2aircraft.net/forum/ot...ngineering-flight-book-8691-2.html#post137292

Just going from B-29 vet's given at the museum. If we have any of them, it's usually when the subject is "Long Range Escorts." Mostly we hear from P-51 or P-47 pilots, but occasionally we hear from a bomber guy.

It is possible they did both, depending on the actual target. I wouldn't argue too hard either way.

GregP said:

Over Japan the B-29's were not operating at cruise speed. They cruised to the target area and accelerated to "attack speed" which was usually between 290 and 335 mph or more depending on the shallow dive. Once out of local fighter range, they decelerated back to cruise speed to the flight home.

The B-17's in Europe never, apparently, tried that tactic. Perhaps the smaller B-29 formation made it possible. It would have been very dangerous to try coordinating a uniform acceleration and dive for several hundred or more bombers.

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Were the B-29's accelerating to attack speed, or were they backing off to prevent engine fires?

They were not backing off to prevent engine fires. Don't be a spokesman for disinformation. The R-3350's had issues but. again, I might remind you the B-29 had the lowest combat loss rate of ANY heavy bomber of WWII. If that's a dangerous engine, I'll fly behind it every time regardless of engines, if given the choice of the B-29 or any other heavy bomber.

If I had to choose one and only one bomber to fly, I'd take Douglas A-26's every time.

Gis238, please don't troll for an argument. If you attend one the talks given by the vets and ask that kind of question, they'll eat you alive and you'll be asked to leave if you do it twice. State your opinion by all means if you can back it up with facts, but it's tough to say something was a death trap when it flew 31,000+ sorties with the lowest loss rate in the USAAF for it's class of aircraft, don't you think?

It was a simple question.

GregP said:

but it's tough to say something was a death trap when it flew 31,000+ sorties with the lowest loss rate in the USAAF for it's class of aircraft, don't you think?

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In the later part of the war, as engine issues were worked out (but not eliminated), and high altitude flights were abandoned, the performance certainly improved, in turn improving the statistics you quote.

What are the stats for the earlier high altitude long duration flights?

You have already suggested that a V-3420 powered B-29 might have improved on this record and I agreed that that may be a worthwhile alternative to explore.

GregP said:

The B-29 could certainly have been improved and it was covered a ways back. The R-3350 was developed and ran very early. Then it languished for 5+ years while they developed the R-2600. If the main customer had asked Wright to concentrate on the development of the R-3550, it would have been ready 5 years sooner, with the attendant benefits of a more mature engine sooner. But that is a what-if and has no bearing on what happened.

You couldn't just hang 6 R-2800's on it without considerable redesign, probably more span, probably requiring more tail and possibly more length. That would waste enormous effort and resources, all for nothing. The B-17 and B-24 were doing the job we needed done and the development of the B-29 was pretty much tied to the development of the R-3350 or other suitable large piston engine ... not the R-2800.

You could certainly develop an alternate aircraft around 6 R-2800's, but doing it with the B-29 would be a waste of effort.

Just my opinion. Apparently Boeing thought the same as they never pursued the concept. In fact. nobody pursued the concept, not even the USAAF.

They DID try the V-3420 and I believe they should have gone that way when the R-3350 proved to need development. It was feasible, would not have resulted in any redesign that was major in any way, and could easily have been switched back over should the R-3350's ills be cured sooner, if so desired. The V-3420 variant also had better performance than the R-3350 counterpart.

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gjs238 said:

In the later part of the war, as engine issues were worked out (but not eliminated), and high altitude flights were abandoned, the performance certainly improved, in turn improving the statistics you quote.

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Not abandoned, limited. Because of errant air currents over the Japanese islands, causing targeting issues.

The B-29 was not the PoS that some people are making it out to be and if it was such a problematic failure, the Japanese sure didn't think so. They spent alot of time and materials to build interceptors in the hopes of stopping it.

The B-29 was a new innovation in technology and anything new always has bugs to be worked out. There rarely is a door-buster in technology that goes from the drawing board to hands-on without some sort of issue being encountered. Even the first Space Shuttle, the Enterprise, was found to have a fatal flaw in the wingroot system that caused the wings to flex under stress. That discovery was made only after it was released from the 747 for it's maiden flight. Had it gone to space, it would have become a supersonic lawndart on re-entry.

So the point here is, yes, the B-29 had problems. Those problems were corrected as time went by, but in the mean time, it's service was what was needed, when it was needed and it got the job done.

gjs238 said:

In the later part of the war, as engine issues were worked out (but not eliminated), and high altitude flights were abandoned, the performance certainly improved, in turn improving the statistics you quote.

What are the stats for the earlier high altitude long duration flights?

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How about "later"? Like Korea?

B-29 in Korean War

The mission here men, is how to help the WWII effort. How can we get the aircraft fielded sooner and improve the early performance?
One suggestion was a different engine.
Another suggestion was two more engines.
Another suggestion was improving development of the historical engine.
All, I am sure, could be interesting discussions, but we keep getting off onto defensive lines of thought.