Joe Broady
Airman
- 99
- May 30, 2019
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For these raids, I'm curious if they removed the gun-computer, or kept that. From what I remember, 300 B-29's were built without the gun-computer installed.
They would typically climb to about 19 - 20 thousand feet and cruise, once they hit a waypoint offshore that turned them towards Tokyo, they'd start their descent and level off at 5 thousand before target.Did they fly 5000' from Tinian to Tokyo and back? Or did they cruise higher?
UnderstoodComputers, plural.
When you say parallax, does that mean the fact that the computer would compute lead and drop, or lead, drop, and the position of the turret relative to the plane's centerline? I figure if the turrets were pointed sideways that would make the bullets seem to curve off behind the aircraft quite a bit. On a fighter it's not as complicated as you have the guns pointing wherever you're flying...The single parallax computers for the
Did they climb back to the same altitude (19000-20000') or to a lower altitude? I remember some profiles for the P-47N when used as an attack-plane, which would see it cruise in at altitude and egress fairly close to sea-level.They would typically climb to about 19 - 20 thousand feet and cruise, once they hit a waypoint offshore that turned them towards Tokyo, they'd start their descent and level off at 5 thousand before target.
This helped both with fuel consumption and maintaining speed for their egress and climb back to altitude for the trip home without burning excessive fuel.
Because of the distances involved, the B-29's pilot had to keep an eye on fuel management, so they would climb back to an altitude that provided a better cruise setting.Did they climb back to the same altitude (19000-20000') or to a lower altitude? I remember some profiles for the P-47N when used as an attack-plane, which would see it cruise in at altitude and egress fairly close to sea-level.
I wasn't trying to suggest they cruised out at sea-level -- I was just trying to determine if they climbed to the same altitude they entered at, or a lower altitude.Because of the distances involved, the B-29's pilot had to keep an eye on fuel management, so they would climb back to an altitude that provided a better cruise setting. The air's density at sea level would mean a higher consumption of fuel, plus a disadvantage if intercepted by Japanese elements.
Understood
When you say parallax, does that mean the fact that the computer would compute lead and drop, or lead, drop, and the position of the turret relative to the plane's centerline?
J Joe Broady
So, if you turn the turret sideways, the reticle will not be displaced further to the side to factor in that the bullets will appear to fly sideways as well as forward?
Basically, when I said "displaced", I meant positioned to factor in lead: As described in the first link, at a distance of 800 yards, gravity will cause the bullet to drop 4.6 yards, so the reticle would be displaced so it matches where the impact point would be.Not sure what you're asking
So the reticle in the sighting station is pointed at the target, with the computer positioning the turret based on where the reticle is aimed?The pipper of a B-29 gun sight has a fixed direction with respect to the sight. It is not displaced to compensate for ballistics and target motion.
I didnt see this post when it was made maybe 'cos it was on my birthday, but as I understand it the pilot of a B-29 was aware of the issues of fuel management but it was the flight engineers job. The flight engineer on a B-29 took more training than the pilot from what I've read and most of the time he was telling the pilot what to do as far as airspeed and altitude goes.Because of the distances involved, the B-29's pilot had to keep an eye on fuel management, so they would climb back to an altitude that provided a better cruise setting.
The air's density at sea level would mean a higher consumption of fuel, plus a disadvantage if intercepted by Japanese elements.
Happy birthday!I didnt see this post when it was made maybe 'cos it was on my birthday, but as I understand it the pilot of a B-29 was aware of the issues of fuel management but it was the flight engineers job. The flight engineer on a B-29 took more training than the pilot from what I've read and most of the time he was telling the pilot what to do as far as airspeed and altitude goes.
Update: In going through some old paperwork, I found a reply from the Air Force Museum to my inquiry about a B-29 named "The Dutchess". The penciled notes are what I wrote while I was on the phone with Paul Tibbets. I thought I would pass this along as someone may be interested.In the '70s a forward section of a B29 fuselage arrived in a local Tucson salvage yard. Nose art identified it as "The Dutchess" and the salvage yard owner maintained that it had been one of the planes involved in the A-bomb program. If this were true it should have been placed in the Pima Air Museum or some other place to preserve it. I undertook to try to trace The Dutchess' history and talked to Paul Tibbets on the phone for 45 minutes about it. Tibbets was friendly and quite helpful and gave me some things to check to see if it had been one of the 509th Composite Group's planes. The most significant feature was the single bomb-bay rather than two shorter bomb bays on a standard production B29. He also related that many other changes were also made to the Wichita production run of these special versions. He gave me Chuck Sweeney's phone number and I talked to him as well. He did not know of a B29 named The Dutchess but said that it might have been one of the Los Alamos research planes.
I never did find out the history of The Dutchess B29 and it disappeared from the salvage yard thereafter.
Wait, at 300 mph that would take 14 minutes for the whole bomb run... what kind of CEP did that have compared to the traditional Norden bombsight, and the LORAN aid (I think they were used in the pacific theater).The 311 lightened B-29B version was interspersed on the Bell Atlanta production line (small batches and sometimes single aircraft) with normal B-29. The normal AN/APQ-13 B-29 radar was replaced on these aircraft with the aerofoil shaped AN/APG-7 Eagle radar and the tail turret was fitted 3x0.5" guns with an AN/APG-15B radar control system. Most went to the 315th Bomb Wing which began to arrive in the Marianas at the end of May 1945, flying their first mission a month later. The Eagle radar needed a 70 mile bomb run but was very accurate. So the group flew at night or in bad weather to avoid interception. Their principal targets were oil related, refineries and storage facilities on Honshu, earning them the nickname "The Gasoline Alley Boys".