B-29 Question.

[skorpx1]

Seeing that the B-29 was an exceptional bomber, and produced in massive amounts, why did it never see service in the European theater? With a 20k ord load you'd think that at least 100 B-29's flying over Berlin would have it leveled and wiped off the map within a week. Was there a reason why it only fought in the Pacific theater or was the 29 planned to be used in Europe?


I'd be googling this but I figured that i'd get more direct and clear answers here.

[Lusche]

B-29 entered war relatively late, at that point it was evident that the 17's 24s et al were adequate to finish the job. Even more important was the range requirement, the B-29's range was absolutely needed in the PTO, in the ETO, not so much.
B-29s were only send for publicity (=disinformation) to England in 1944.

[Karnak]

Seeing that the B-29 was an exceptional bomber, and produced in massive amounts, why did it never see service in the European theater? With a 20k ord load you'd think that at least 100 B-29's flying over Berlin would have it leveled and wiped off the map within a week. Was there a reason why it only fought in the Pacific theater or was the 29 planned to be used in Europe?


I'd be googling this but I figured that i'd get more direct and clear answers here.

20,000lbs isn't that much more than 14,000lbs or 13,500lbs and there were well more than 100 Lancasters and Halifaxes flying over Berlin on a regular basis.

[earl1937]

Seeing that the B-29 was an exceptional bomber, and produced in massive amounts, why did it never see service in the European theater? With a 20k ord load you'd think that at least 100 B-29's flying over Berlin would have it leveled and wiped off the map within a week. Was there a reason why it only fought in the Pacific theater or was the 29 planned to be used in Europe?


I'd be googling this but I figured that i'd get more direct and clear answers here.

  As Snailman pointed so accurately, the mission profile for the 29 was completely different than the 17 or 24. Because of the range requirements in Pacific, and flying out of bases in the Mariana's, Tinian, for example, you still had a 10 hour mission or more, depending on the target hit that day, so crew comfort was high on the requirements for development of the 29. (pressurized aircraft).
One of the problems when it was under development was this: The U.S. knew that the J2M "Raiden", which had a service ceiling of about 38,000 feet, and was capable of speeds in excess of 400MPH. It had 4 20MM cannon and 621 were built, but were never used properly by the Japanese. So the thinking was at the time, I guess, was, since at the time of design, there really wasn't an American fighter capable of flying to Japan with this B-29, so it had to be an independent weapon, which was not dependent upon a fighter for escort.
Problem was, by the time the 29 starting flying missions over Japan, most of the top Japanese pilots had been killed in action, so the perceived threat of the Raiden never really was a problem for the 29's.

[Saxman]

  As Snailman pointed so accurately, the mission profile for the 29 was completely different than the 17 or 24. Because of the range requirements in Pacific, and flying out of bases in the Mariana's, Tinian, for example, you still had a 10 hour mission or more, depending on the target hit that day, so crew comfort was high on the requirements for development of the 29. (pressurized aircraft).
One of the problems when it was under development was this: The U.S. knew that the J2M "Raiden", which had a service ceiling of about 38,000 feet, and was capable of speeds in excess of 400MPH. It had 4 20MM cannon and 621 were built, but were never used properly by the Japanese. So the thinking was at the time, I guess, was, since at the time of design, there really wasn't an American fighter capable of flying to Japan with this B-29, so it had to be an independent weapon, which was not dependent upon a fighter for escort.
Problem was, by the time the 29 starting flying missions over Japan, most of the top Japanese pilots had been killed in action, so the perceived threat of the Raiden never really was a problem for the 29's.

Not only that, but high-altitude strategic bombing over the Japanese islands proved largely ineffective, anyway.

[DaveBB]

The B-29 was fragile.  It was SOP in the PTO on takeoff that if an engine had a runaway temperature, that the crew was to bail out.  This may sound bit odd, but the B-29 had a few design flaws that resulted in catastrophic consequences.  The first design flaw were the valves on the rear cylinders.  They were subjected to much higher temperatures than the front cylinders.  If the valves stuck open, this could cause a fire in a few different ways.  Secondly, the magnesium accessories box mounted at the rear of the engine was a powder keg.  Once magnesium catches on fire, it burns very hot and is almost impossible to put out.  So if the flight engineer saw an engine temperature rising for no apparent reason, the crew was to bail out immediately.  Boeing engineers calculated it took only 90 seconds for a magnesium fire to burn through the main wing spar.

The most common cause of maintenance headaches and catastrophic failures was the engine. Though the Wright R-3350 would later become a trustworthy workhorse in large piston-engined aircraft, early models were beset with dangerous reliability problems, many caused by demands that the B-29 be put in operation as soon as possible. It had an impressive power-to-weight ratio, but this came at a heavy cost to durability. Worse, the cowling Boeing designed for the engine was too close (out of a desire for improved aerodynamics), and the early cowl flaps caused problematic flutter and vibration when open in most of the flight envelope. The 18 radial cylinders, compactly arranged in front and rear rows, overheated because of insufficient flow of cooling air, which in turn caused exhaust valves to unseat.

These weaknesses combined to make an engine that would overheat regularly at combat weights, particularly during climbs after takeoff. Unseated valves released fuel-air mixtures during engine combustion that acted as a blowtorch against the valve stems. When these burned through the engines disintegrated and caught fire. A fire that was not immediately contained in the forward part of the engine by fire extinguishers became impossible to put out. An accessory housing manufactured of magnesium alloy in the back of the engine would often catch fire and produced heat so intense it burned through the firewall to the main wing spar in no more than 90 seconds, resulting in catastrophic failure of the wing.

http://www.allpar.com/history/military/b-29.html

[earl1937]

Not only that, but high-altitude strategic bombing over the Japanese islands proved largely ineffective, anyway.

You are right! The reason being the constant "jet" streams which flowed over the islands of Japan. At the time the 29's were flying over there bombing, no one knew the effect the "jet" streams would have on bombing accuracy!
"Dumb" bombs are just that, Dumb! That is why the "guided" bombs of the "Desert storm" era became so famous, we could all watch them on TV, and all the bombardier had to do was put in the right co-ordinates of the desired target and no amount of wind or anything else was going to keep it from its assigned target.
Not sure why the "jet" streams around the European theater of operations did not have the same effect as winds over Japan, but maybe it did, as the target over Europe was considered hit, if the bomb landed with in a 2 mile radius of the target.  

[bozon]

20,000lbs isn't that much more than 14,000lbs or 13,500lbs and there were well more than 100 Lancasters and Halifaxes flying over Berlin on a regular basis.

Together with the two drones that is 21,000 lbs more per formation. Oh wait.....

[earl1937]

The B-29 was fragile.  It was SOP in the PTO on takeoff that if an engine had a runaway temperature, that the crew was to bail out.  This may sound bit odd, but the B-29 had a few design flaws that resulted in catastrophic consequences.  The first design flaw were the valves on the rear cylinders.  They were subjected to much higher temperatures than the front cylinders.  If the valves stuck open, this could cause a fire in a few different ways.  Secondly, the magnesium accessories box mounted at the rear of the engine was a powder keg.  Once magnesium catches on fire, it burns very hot and is almost impossible to put out.  So if the flight engineer saw an engine temperature rising for no apparent reason, the crew was to bail out immediately.  Boeing engineers calculated it took only 90 seconds for a magnesium fire to burn through the main wing spar.

http://www.allpar.com/history/military/b-29.html

 I am not sure how accurate this man's info is! The only "magnesium" parts that I knew anything about were the "dynafocals", which attached the engine to the wing, in the accessory section. The whole purpose of these was that if the engine caught fire, they would burn into and the engine would fall off the wing! I never heard of one doing that, but did see one land one time in Japan with the #3 engine "drooping" about 20 degrees because the top two mounts had burned into, but it did not fall off the wing.
One thing of note though, if you will look at any of the pictures from that time frame, you will see, waiting on takeoff, long lines of B-29's. The 29, as long as cowl flaps were fully open, did not have a heat problem, the problem came when you closed the cowl flaps to 10 degree settings for takeoff! The reason for that was the vibration of the elevator above 90 knots IAS. Engines 1 and 4 cowl flaps did not effect the elevators like 2 and 3, so our procedure was this, as soon as we approached VR speed on takeoff, usually around 105 to 115 knots IAS, depending on the load, #2 and #3 were placed in trail by the engineer, but 1 and 4 were left at 10 degrees. As soon as we broke ground, if I remember correctly, #1 and 4 were also placed in  trail, for accretion purposes as those big old cowl flaps would hinder the acceleration of the aircraft to V4 then to VX then to VY, again depending on load out,, as these speeds varied with load out. Then the engineer would adjust cowl flap settings to what ever opening for cooling purposes, but 2 and 3 were never open more than 10 degrees at any time because of the effect they had on the elevators.
I was never "trained" to bail if we had an engine fire, which we did on serveral occasions during 924 hours in the beast, but always the on board fire protection system would put them out, but we always had to shut down the engine. That was first order of business in the event of a fire!
Not real sure on this, but I believe the R-3350 "compound" engines were re-designed after the A and B models of the 29. The "C" model, which I was envoloved in, had the same engine as the Lockheed 1049G super "connie", and also the first of the Boeing model 377's had the same engine, but later were changed to the R-4360 engine.


But the 1049G always had the R-3350, as far as I know and there may have been some problems with the engine, when you look at the DOT accident reports on this aircraft, I could only fine 2 which crashed due to engine fire.


Maybe this is another case of "reputation" giving the aircraft a bad name through inaccurate information!

[earl1937]

The B-29 was fragile.  It was SOP in the PTO on takeoff that if an engine had a runaway temperature, that the crew was to bail out.  This may sound bit odd, but the B-29 had a few design flaws that resulted in catastrophic consequences.  The first design flaw were the valves on the rear cylinders.  They were subjected to much higher temperatures than the front cylinders.  If the valves stuck open, this could cause a fire in a few different ways.  Secondly, the magnesium accessories box mounted at the rear of the engine was a powder keg.  Once magnesium catches on fire, it burns very hot and is almost impossible to put out.  So if the flight engineer saw an engine temperature rising for no apparent reason, the crew was to bail out immediately.  Boeing engineers calculated it took only 90 seconds for a magnesium fire to burn through the main wing spar.

http://www.allpar.com/history/military/b-29.html

Another thing which I question is his statement that on Aug 1st, 1945, 836 B-29's took off to attack 12 different cities, but only 784 RTB'd. That is the loss of 92 B-29's in one mission and I can find no record of that many being lost in one mission. Remember, Aug 1st, the Japanese had very few fighters left in which to try to intercept the bombers, so if 92 were lost, what brought them down.
His opening statement about the 29 being a "fragile" aircraft is certainly not true! It was a tough bird and could take a lot of punishment, so don't know what he is refereeing to there!

[DaveBB]

There were enough Heavy Bomber losses in August of 1945 in the PTO to account for such an alleged high number of B-29 losses.  Though I am sure more than half of those were due to mechanical failure and running out of fuel.  Here is the Air Forces official list of "Very Heavy Bomber" losses for August 1945:

http://www.usaaf.net/digest/t101.htm

[earl1937]

There were enough Heavy Bomber losses in August of 1945 in the PTO to account for such an alleged high number of B-29 losses.  Though I am sure more than half of those were due to mechanical failure and running out of fuel.  Here is the Air Forces official list of "Very Heavy Bomber" losses for August 1945:

http://www.usaaf.net/digest/t101.htm

Yes, that is the figures I see also, but the author of that B-29 thing says on Aug 1st, we lost 92 bombers, by his figures. Now maybe he meant to say during August, I don't know, but we never lost 92 B-29's in one day!

[DaveBB]

I agree. I don't know if we totally lost 92 B-17s in one day.

[colmbo]

But the 1049G always had the R-3350, as far as I know and there may have been some problems with the engine, when you look at the DOT accident reports on this aircraft, I could only fine 2 which crashed due to engine fire.

In the early 80s there was a Connie being ferried out of Anchorage to the lower '48 for "restoration".  Right at rotation they blew a jug on #3 (departing head left a large hole in the cowling) and had an engine fire as a result.  As they made a 180 out west of the airport we got a planform view the airplane with flame streaming back from the #3 engine to the horizontal stab --- very impressive sight.  The crew got the airplane back to the runway, we knocked the fire out and the airplane was eventually flown out of Alaska.  Suffered a big oil leak over Arizona, eventually made it to the east coast where it was being used for parts.  I have a recording of the Tower, Ground and Crash radio transmissions around here somewhere.

Aircraft was N8083H.

[earl1937]

In the early 80s there was a Connie being ferried out of Anchorage to the lower '48 for "restoration".  Right at rotation they blew a jug on #3 (departing head left a large hole in the cowling) and had an engine fire as a result.  As they made a 180 out west of the airport we got a planform view the airplane with flame streaming back from the #3 engine to the horizontal stab --- very impressive sight.  The crew got the airplane back to the runway, we knocked the fire out and the airplane was eventually flown out of Alaska.  Suffered a big oil leak over Arizona, eventually made it to the east coast where it was being used for parts.  I have a recording of the Tower, Ground and Crash radio transmissions around here somewhere.

Aircraft was N8083H.

Good to see yu sir, we been worried about where you been! BTW, the connie you refere did not crash, and there may have been more incidents about the aircraft, but unable to find much on engine problems, although I know they had some.