Mission to Moscow-hypothetics

[HoHun]

Hi Delcyros,

Here is the cruise control chart from the B-29 Airplane Commander Training Manual (AAF Manual No. 50-9).

It looks like Moscow is within easy reach for the B-29 - I figure the bomb bay tanks won't even be necessary, and the plane will climb quicker and cruise higher without.

The altitude limit of the chart (rather than the aircraft however shows that cruising at 30000 ft, though possible, is not usually expected from the B-29.

Regards,

Henning (HoHun)

[timshatz]

Delc, read the chart. Yeah, that's what it says. True air speed and Indicated Air Speed are very different due to altitude and temperature. Maybe I spend to much time below 10k to notice it. Tell the truth, first time I've heard of it. Gotta get somebody like Flyboy J or Mkloby to eyeball. They have more stick time than I do.

As for working out the throttle settings for a B29 in that configuration (close to max weight), it will take somebody with a lot of knowledge on the engineer's station. I believe they had a lot to do with keeping the engines happy. Maybe Syscom again.

One thing that did pop into my head is the density altitude for England in August. If it is hot, muggy day, they are going to need every inch of runway to get up. Just another detail to think about. What is the density altitude of the home field at 2200 on the night of the mission? It could make the takeoff a bit wild for the pilot and crew (visions of Lindberg taking off for his transatlantic flight would look similar).

One last point. Both the airplane and the crew are going to be very important for the Soviets to get their hands on. Both would be best, but if it comes to a choice, they would probably prefer the crew. What they know about the mission (and the parameters of the bomb) would be more extensive than the aircraft itself.

Just a thought.

[Njaco]

Feel like I'm a sniper here...any thought to a Halpro / Ploesti type mission? Low on the deck, out of radar until near target. What would be the engine performance at a lower altitude? I'll go away now.

[Graeme]

Originally Posted by Njaco

Feel like I'm a sniper here...any thought to a Halpro / Ploesti type mission? Low on the deck, out of radar until near target. What would be the engine performance at a lower altitude? I'll go away now.

Fear not comrade, their capitalist plot will come to nought, I have informed the Motherland and they are ready!

[timshatz]

Originally Posted by Njaco

Feel like I'm a sniper here...any thought to a Halpro / Ploesti type mission? Low on the deck, out of radar until near target. What would be the engine performance at a lower altitude? I'll go away now.

On the way in, maybe. But it would be hairy. 1500 miles at tree top level. UGGGGHHHHH, that's gonna be a lot of work for the pilots. Plus, the sun will be up about half way through the mission. And the VVS is a low altitude air force. You'd be in their back yard, playing in their sandbox. Not good. All those Yaks and Laggs would be a real nusiance

Plus, you're fuel consumption is generally pretty high at low altitudes and relatively high speed. Can't do a 220 knot run down there. Have to be up as fast as it can go without blowing the engines up. On top of that, you'll have to climb (fast) to altitude of 25-30K to set up for the bomb run/bombing. Lower and you end up closer to the blast zone.

So, in short, you're climbing at 170 mph, within 200 miles of Moscow with fighters on you thicker than flies on a turd.

The only way I could think it would work is with a delayed detonation (parachutes and a drop at 10K or so) or with a smaller bomb, smaller (and faster) aircraft doing a pull up and bomb pitch from some miles out, pulling over the top and making a run for it back the way it came.

[timshatz]

Originally Posted by Graeme

Fear not comrade, their capitalist plot will come to nought, I have informed the Motherland and they are ready!

No worries, we have a secret weapon. A vodka sniffing missle! 100% effective in Mother Russia.

[delcyros]

HoHun wrote:

It looks like Moscow is within easy reach for the B-29 - I figure the bomb bay tanks won't even be necessary, and the plane will climb quicker and cruise higher without.

Henning, Can You explain this to me? I have checked every detail of the map but there indeed is no part relative to range on this chart. All You can derive from it is specific fuel consumption at a given horsepower, load and altitude. So I assume, You made a flight chart in order to get Your figures? Please feel free to post them.

Timshatz wrote:

One thing that did pop into my head is the density altitude for England in August. If it is hot, muggy day, they are going to need every inch of runway to get up. Just another detail to think about. What is the density altitude of the home field at 2200 on the night of the mission? It could make the takeoff a bit wild for the pilot and crew (visions of Lindberg taking off for his transatlantic flight would look similar).

The runway is concrete and 9.000ft. long, so I think it should work under good conditions (head wind is necessary). But we have to figure out whether or not the B-29 has to engage a climb immediately after take off or not. Problems I see in the engine cooling. At Guam they flew at comparable loads and had to dive down the 500ft. cliff before establishing a level flight and climb state finally. Not sure about Tinian as this airfield had no such slope. Don´t now either if our starting airport has trees in vicinity or not but construcion works should be possible in the timeframe in question.

I am working on a wind condition but it is difficult to figure out which figures could be known to the USAAF meteorological service and what couldn´t. There were no meteostations in a radius of 800-1000mls around Moscow accessable to the USAAF weren´t?

[Hop]

Looking at the maps and aerial photos, trees and buildings shouldn't be a problem at any of the 3 emergency fields. Manston is at 170 feet, with slopes down from either end, and no trees near. Both Woodbridge and Carnaby are lower, at about 30 - 40 ft, Woodbridge has trees about 3,000 ft from either end of the runway.

[timshatz]

Delc, have also read about loaded B29s taking off and flying in the ground effect. Some flew for a considerable distance in it. Not really an option in England.

However, having read HoHun's chart, it looks like there is only 4% more power required with a 5,000ft density altitude. That should be no problem.

The B29 has a helluva lot of power to it!

As for the weather en route, I would guess you would run out of timely info somewhere near Denmark. After that, it would be forecast weather.
I don't think the Soviets were big on giving out weather forecasts to anyone. Even their own citizens!

[HoHun]

Hi Delcyros,

>Henning, Can You explain this to me? I have checked every detail of the map but there indeed is no part relative to range on this chart. All You can derive from it is specific fuel consumption at a given horsepower, load and altitude.

The horizontal axis for the central diagram is cruise speed, and we know the fuel capacity of the B-29, so we can derive range. (From the manual, I'd say your first post actually listed a B-29A, while I think we'd have a "plain" B-29 with a slightly larger centre tank. I might be wrong, though.)

What we don't know is the actual cowl flap position, but it seems the WW2 aircraft were fairly content with small openings at high altitudes due to the low air temperatures.

I have zig-zagged over the chart a couple of times, but only to figure out the general trend. It takes a lot of work to derive an accurate flight plan from that complex chart, so I'm afraid I can't offer anything definite.

Regards,

Henning (HoHun)

[Cub Driver]

Originally Posted by Graeme

'Role play'. What's our 'motivation' for wanting to destroy Moscow?-hypothetically.

It wasn't hypothetical. During the Berlin crisis of the late 1940s, Truman sent B-29s to England to impress the Russians with the risks they were running by blockading Berlin. As it happens, they weren't Silverplate models, and the U.S. probably had no deployable atomic bombs at the time, but the bluff was there.

What good is a bluff if it can't be carried out?

Blue skies! -- Dan Ford

[Cub Driver]

London to Moscow is 1359 nautical miles.

Guam to Tokyo is 1354 nautical miles -- and the 29s often went much further than Tokyo.

Blue skies! -- Dan Ford

[Graeme]

Originally Posted by Cub Driver

It wasn't hypothetical. During the Berlin crisis of the late 1940s, Truman sent B-29s to England to impress the Russians with the risks they were running by blockading Berlin. As it happens, they weren't Silverplate models, and the U.S. probably had no deployable atomic bombs at the time, but the bluff was there.

What good is a bluff if it can't be carried out?

Blue skies! -- Dan Ford

I agree,..but the gents who are constructing this imaginary 'scenario' have picked "August 1945".

[delcyros]

Hop, again thanks for the contribution!

The horizontal axis for the central diagram is cruise speed, and we know the fuel capacity of the B-29, so we can derive range. (From the manual, I'd say your first post actually listed a B-29A, while I think we'd have a "plain" B-29 with a slightly larger centre tank. I might be wrong, though.)

Have You included the fuel burned for distance at specific average gross weight and during climb to altitude? BTW, I had the B-29 f.e.m. cruise chart (in a much worser resolution) and will use this chart (which looks like B-29B to me in every detail), thanks for posting it, Henning.

What we don't know is the actual cowl flap position, but it seems the WW2 aircraft were fairly content with small openings at high altitudes due to the low air temperatures.

This explenation does not sound correct to me. From my understanding the cooling efficiency is reduced at altitude due to the lower airdensity and thus the lower specific thermal transfer potential of the gases. I find this assumption confirmed in various high altitude piston A/C engeneering instruction manuals.

Cub Driver, The mission profile is vastly different for Tokyo raids and our Moscow raid. The cruise altitudes were pretty low (typically 8.000-18.000ft.), there was escort cover and several emergancy landing fields close by (Iwo Jima, Okinawa). I fear, the mission to Moscow does not enjoi these advantages.

Beside this sceptizism, I would like to see how such a flight can be made. It can be done, sure, but it requires careful planning.
It all bottles down to several question remaining:

1.) What is the presence of VVS forces in august and where.
2.) What is the state of the PVO Moscow, Leningrad and Stalingrad?
3.) How can the US establish a weatherforecasting for the area in question?
4.) How far can the USAAF provide escort to the B-29 (and thus reducing the cruise altitude for a more economic cruise speed)?
5.) How could the Flightplan look like?
6.) Which weather- / and runwayconditions are necessary for an unproblematic take off?
7.) Which is the best timesetting for the mission (e.g. most part beeing made in darkness)
8.) does the VVS/PVO have high altitude / nightfighters?

It seems that without a proper high altitude weather forecast, the B-29 is forced to fly with lowered radardome (-10 mp/h cruise speed, -9% cruising range) just in order to keep on track with navigational issues.

best regards,
delc

[syscom3]

I would like to also point out that the B29's that took off from the Mariana's would cruise at low altitude almost to the Japanese coast, then climb for altitude. This saved them lots of fuel.

This scenario for Moscow might not work, due to the B29 having to maintain mid and high altitude flight profiles to the target.