Mission to Moscow-hypothetics

[delcyros]

A couple of interesting points.

For role playing:
Situation is as following:
Nov. 44, Two B-29 landing in Eastern Russia following battle damage over Japan (as historical), the crews are taken prisoner but are allowed to "escape" (as historical), the B-29 have to stay in Russia
Dez.44, The US sends a note of protest regarding the two B-29. (unhistorical but probable)
jan.45-april45, strategic bombing campaign carried out over Germany as historical, The SU notes that the majority of the campaign is relegated to secondary industrial infrastructures, which have no effect in the expected (short) remaining duration of war but almost the whole effort is concentrated on what will become the future soviet occupied zone of Eastern Germany. Stalin get´s angry.
april 45, a Yak-9 fighter forces a B-29 to land in the far east (as historical).
Several minor clashed of soviet and US fighters over central europe (as historical).
may 45, VE-day. Russia refuses to declare war on Japan following it´s non aggression pact with Japan. (unhistorical)
may, 45, The US refuse to send further land lease material to Russia (unhistorical)
june 45, the race for technology get´s out of controll. After some small command operations to "free" german scientist in estern Germany (Alsos, as historical), the US Army demolated facilities in Thuringia to prevent them from falling into SU hands. The SU does similar things in Austria.(ahistroical)
Both forces prepare operations of larger scale. Rumors are that Britain stores german captured weapons for a possible war against Russia
Jule 45, SU upbuild of power across the Elbe, Stalin is silly and somehow forced by the critical food situation to do something...

Tim,

A flightplan would be highly welcome! Perhaps You can help me here.
According to the flight engeneers manual posted by Micdrow, a B-29 at close to 130.000lbs gross take off weight needs est. 1200 gallons (7.200 lbs) of fuel
to climb to 30.000ft. altitude and it will cover a distance of ~320-340 mls during this climb (est.). Avg. speed for the climb is 224 mp/h so the B-29 might reach service altitude somewhere close to the german bay, approx. 1 hour and 30 minutes after take off. Can anyone doublecheck this?

A: CLIMB
Take off gross weight: ~130.000lbs (7.960 gallons = 47.760 lbs)
Fuel to climb to 30.000ft: 7.200 lbs (1.200 gallons)
Avg. TAS in climb: 170+278/2= 224 mp/h
Distance of climb covered until reaching service altitude: ~330 st.mls
Time covered to reach service altitude: 1:29
gross weight at service altitude: 122.800 lbs (40.560 lbs fuel left)

B: CRUISE TO TARGET

Distance left to target: 1.220 mls
cruise setting: 77% power (maximum cruise setting, necessary setting for 30.000ft. cruise altitude), each engine: 1.550 hp, 2150 rpm, auto rich, fuel flow: 155 gln/hr @ 25000ft. -how much at 30.000ft.?)
I originally wanted a lower cruise setting but this setting is necessary to keep the altitude high enough with the given gross weight.

Temp.: -44.4 degees C (-48 degress F)
IAS: 155 mp/h
TAS: ~250 mp/h (excluding wind factors, ~217 Kts)
one hour endurance at this setting= est. 620 gallons (3.720 lbs), adjusted for the avg. gross weight: 650 gallons (3.900 lbs) -absolutely not sure here-
avg. gross weight during cruise: 113.300 lbs

Time to destiny: 293 minutes (4,88 hours)
est. fuel consumption: 3.712 gallons (~19.000 lbs)
gross weight at target area: 103.800lbs (21.560 lbs fuel left)

C: BOMBING RUN
as suggested by Tim, 10 minutes @ military rating, including the 155 degrees about turn. Fuel flow is 290 for each engine (194 gallons or 1.160 lbs fuel total)
Nuke dropped.
flighttime before return cruise: 392 minutes (6.53 hrs or 6 hours and 32 minutes)
Gross weight before return cruise: 93.640lbs (20.400 lbs fuel or 3.400 gallons left)

With est. 43 % fuel left, is the B-29 able to reach England or for this matter bases at northern Italy? And, if the answer is yes, under which conditions (cruise setting)?

[delcyros]

At august 18th, the soviet armies should be able to advance at least to the Rhine valley, were the UK/US forces should be able to establish a defense line. Danmark is under controll (Bornholm was indeed occupied) and soviet forces are advancing in Northern Norway, too. Greece remains mostly neutral as will be Turkey, the Iran and China. Soviet forces in the south advanced to the alpes, with the souther front established at western Slovenia on the italian border.

Strength of the VVS in Germany by then is:

7.180 planes operational
Il-2 mostly replaced by IL-10 (30%)
Yak-3, Yak-9, La-7 and even few La-9 (40%),
Pe-2, Pe-3 and a good number of Tu-2 bombers. (15%)
15% other planes (scouting, transportation and other)

The strength of the red army is approx. 12 million under arms at begin of the hostilities.

[Njaco]

As was established during the war, wouldn't the Allies have air superority which would make any advance by USSR difficult. Anyhow, for play sake, looks good and sets up the Moscow mission.

But one question. Was a nuke available at that time so shortly after Japan?

[T4.H]

Good question.

I think...No

They have had enough material for 3 bombs, not for four.
But they captured uranium from a german submarine (U21-class?, which was perhaps used for one of the three first bombs).
I don't know, if enough material was left for a fourth one.

[delcyros]

They had a second plutonium core ready to be shipped. Beside this, they had 60 bomb castings already stored and three more nukes to be avaiable until sept.

Section 8.0 The First Nuclear Weapons

The three reactors (B and D which went started up for production in December 1944, and F which started up February 1945) at Hanford had a combined design thermal output of 750 megawatts and were theoretically capable of producing 19.4 kg of plutonium a month (6.5 kg/reactor), enough for over 3 Fat Man bombs. Monthly or annual production figures are unavailable for 1945 and 1946, but by the end of FY 1947 (30 June 1947) 493 kg of plutonium had been produced. Neglecting the startup month of each reactor, this indicates an average plutonium production 5.6 kg/reactor even though they were operated at reduced power or even shut down intermittently beginning in 1946.
The Hanford reactors accumulated unexpected neutron irradiation damage (the Wigner effect) and in 1946 they were shut down or operated at reduced power. If war had continued they both would have been pushed to continue full production regardless of cost or risk.

No later than august 24th, a second plutonium nuke would become avaiable as a note to sec. Stimson dated to june 45 proove.

Therefore, the deployment list for nukes in august 45 looks as:

1.) Hiroshima
2.) Moscow
3.) (if necessary) Nagasaki

[T4.H]

So, they have had enough material for a plutonium bomb.

I didn't expect, they could produce so much plutonium!

[timshatz]

Delc. I'll see if I can post the flight route I did last night. I had it going straight across Denmark. With Denmark being occupied, it would affect the flight somewhat. But they would go over in the dark and I have not heard anything about Soviet night interception abilities that would cause me to wonder if they would make it. By that time, they would also be at cruise altitude. Tough to scramble and catch a bird going that fast, that far up. Plus, an RAF Night Fighter Intruder attack would probably take care of anything buzzing around below 20K.

I have a few questions about the flight assumptions. You have a climb out speed of 170 mph. Sounds about right for a long climb. What is the 278 number referencing?

IAS/TAS has a substantial difference for cruise to target. Is that a typo?

But both points are minor. I think you have a defensible position on your mission specs. I am not an expert on B29 operations so there is a limit to what I can say but I would add a few points.

First, the fuel burn will lessen as the aircraft gets lighter due to the fuel burn. What is burned on the way out, is not what will be burned (given the same airpseed) on the way back. By that time, the gross of 130K will be down by about 25%. I would think that would add about an hour on the way back. Just a guess, but there will be no climbout to worry about. On the other hand, the cruise speed will be higher to avoid interception.

Even being lighter, I do not think the B29 has enough fuel to make England at high cruise with a 45 minute reserve. She will have to put down beforehand. Northern Italy (Aviano?) is the first call. After that, we'd be looking at North Central Italy, Milan would be the furthest West.

With the Soviets as far as the Rhine, the B29 would probably want to avoid France. That is where the lion's share of the VVS would be. The Balkans (and southern Europe) would probably have a substantial presence, but that is not the big show. It will definitely be Germany.

Will tinker with flight plan and get back with you.

[timshatz]

Another point that comes to mind and has not been addressed is the prevailing winds over the Continent at that time of the summer. It will definitely affect fuel consumption.

Needs to be factored in and needs to be, for lack of a better word, invented.

[Njaco]

Ah, but the jet stream wasn't discovered until after the war, am I correct? May have to modify those stats alittle.

[delcyros]

Theanks for the efforts, so far.

Tim, if You cannot post the flightplan via this community, try skype. That should work! Thank you very much for Your help.

I agree about Danmark. Fighter cover should be able to hold down VVS forces, esspeccially if we take the time into consideration, too.

Regarding the different speeds, I relyed on the flight engeneering instruction manual. There you can see the climb speed depending on altitude. At low altitude (high air density = high reltive lift factor) You can attain a better climbing angle, given with 170 mp/h over ground (no wind) while the higher You get, the faster You need to be to still attain any climb. On the climb chart 30.000ft. are marked with 274 mp/h. The average of both is the mean speed over ground (no wind) during the climb. I assume this is close enough. Climb is attained at full power rating.

The IAS/TAS is also derived from this manual. IAS refers to instrument readings depending on altitude and temperature, while TAS is the translation into "true speed", altough without wind.

Wind factor is a serious one. The jet stream is definetly a factor out there if cruising at 30.000ft. altitude. Perhaps it is better to cruise a bit lower, say 25.000ft. in order to bypass the jet stream and preserve fuel thanks to a lower powersetting? Altough 25.000ft. over Russia may be problematic! The B-29 may start to climb from 25.000ft. to 30.000ft. in the eastern Baltic perhaps.
Normal wind vectors needed to be taken into consideration, too. cross wind is the worst aspect. A wind chart could help out here, altough we then had to ask how much of such a windchart was avaiable to the USAAF in august 1945?


BTW, the longest mission flown by B-29 was a 3,900 mls range flight in the night of 10th/11th august 1944 from Chengtu to Palembeng and return. One out of 39 B-29 landed 90 mls. short due to fuel exhaustion and I assume all were running on fumes at the end. I do not know about the state of the planes (gunnery system) nor about the fuel load, the payload is given with 10.000lbs. Cruise altitude & speed had to be very low & slow altough unknown in detail (except that the bombing might have been executed at 26.000-28.000ft.).

The Akita raid at the very end of ww2 also was an extreme long range mission at pretty low altitude & speed.

Can these experiences from the Pacific help our european scenario?

[Njaco]

Just being picky Del but can you factor in something that hadn't been discovered for your timeframe. Like I said I believe the jetstream wasn't figured out until '46 or '47. They started checking things out when they had different flight times during the raids on Japanese mainland. Not sure when but believe it was after the war.

But how close are we keeping it real?

[timshatz]

Delc, the experiences from the Pacific will help. It shows the combat range could go out to close to 4000 miles. Do we know what the bomb load was? I'm guessing it was in the 4-5000lb range. But that is purely a guess.

As for the other questions about air density and IAS/TAS, I follow as much. However, it's been my experience with other aircraft (all private) that they burn more fuel and fly slower than the book! What happens is you start to lean out the mixture as your altitude gets higher, giving you a better mixture. But that causes the engine temp to climb. So you rich it up some. Long and short, there is a constant dance between power, fuel flow and engine temp(inches of mercury or pressure in the engine is a direct correlation). Just something to keep in mind.

As far at the IAS/TAS is concerned, never seen a variationg (or experienced one that high) for non wind corrected flight. That is why I was concerned it was a typo. Just seems non-correlated.

The winds are going to have to be invented. And with a 1500 mile flight in one direction, they will change a couple of times during the flight. From all directions. A storm front over the North Sea will give both head and tail winds. Passing north or south of a front near Finland will give crosswinds. Run into Thunderstorms over Russia (a possibility during the flight) and you'll have the pilot deviating around them (if he has any sense). Given that it is summer, you'll probably get a mixed bag of weather all along the route.

Did not have time to do flight planning last night. Will try to get to it tonight.

[timshatz]

Here is a map of the route out. Moved a waypoint to Kiel on the way so we could avoid Swedish Airspace (we at least have to try and stay out of there). Moved the second way point to Liepaja. Seemed better than Riga. Come and go fast as apposed to giving the opposition time to figure out what was going on. For some odd reason, penisulas are usually heavy military presence.

Here is the math of the flight.

Route segment 1
Route between EGUL (LAKENHEATH, UNITED KINGDOM) and EDHK (KIEL, SCHLESWIG-HOLSTEIN, DEUTSCHLAND (GERMANY)):
Distance along great circle: 417.1 statute miles, 362.5 nautical miles, 671.3 kilometers
Initial true great circle heading: 67.2 degrees (east-northeast)

Flight time at 220 knots: 1 hours 38 minutes



--------------------------------------------------------------------------------

Route segment 2
Route between EDHK (KIEL, SCHLESWIG-HOLSTEIN, DEUTSCHLAND (GERMANY)) and EVLA (LIEPAJA, LATVIA):
Distance along great circle: 453.0 statute miles, 393.7 nautical miles, 729.1 kilometers
Initial true great circle heading: 66.5 degrees (east-northeast)

Flight time at 220 knots: 1 hours 47 minutes



--------------------------------------------------------------------------------

Route segment 3
Route between EVLA (LIEPAJA, LATVIA) and UUDD (MOSKVA (MOSCOW), MOSKOVSKAYA OBLAST', RUSSIA):
Distance along great circle: 652.5 statute miles, 567.0 nautical miles, 1050.1 kilometers
Initial true great circle heading: 89.7 degrees (east)

Flight time at 220 knots: 2 hours 34 minutes



--------------------------------------------------------------------------------

Total Route EGUL - EDHK - EVLA - UUDD
Total Route Distance: 1522.6 sm, 1323.1 nm, 2450.4 km
Total Flight Time at 220 knots: 6 hours 0 min


Here is a pic of it on a map.

[delcyros]

Thanks Tim, I will use this as the basic approach map.

Njaco, we will try to keep it as real as possible. So we will make steps without taking the jet stream into account (and afterwards we will see how much our estimations are off and finally conclude whether or not these "offs" may cause a failed mission profile or not).

It´s just a single flight (probably has better chances than a massive air raid to get in unnoticed) to be studied, but a weird one.

Do we know what the bomb load was? I'm guessing it was in the 4-5000lb range. But that is purely a guess.

I have no idea. Perhaps Syscom3 knows? He is very knowledgable and has shown great interest into B-29 matters.

However, it's been my experience with other aircraft (all private) that they burn more fuel and fly slower than the book! What happens is you start to lean out the mixture as your altitude gets higher, giving you a better mixture. But that causes the engine temp to climb. So you rich it up some. Long and short, there is a constant dance between power, fuel flow and engine temp(inches of mercury or pressure in the engine is a direct correlation). Just something to keep in mind.

How could this be qualified? Intersting, I didn´t knew.

As far at the IAS/TAS is concerned, never seen a variationg (or experienced one that high) for non wind corrected flight. That is why I was concerned it was a typo. Just seems non-correlated.

It comes from the flight engeneers manual, compare the attached pic below.

The winds are going to have to be invented. And with a 1500 mile flight in one direction, they will change a couple of times during the flight. From all directions. A storm front over the North Sea will give both head and tail winds. Passing north or south of a front near Finland will give crosswinds. Run into Thunderstorms over Russia (a possibility during the flight) and you'll have the pilot deviating around them (if he has any sense). Given that it is summer, you'll probably get a mixed bag of weather all along the route.

Very true. Have to think about this.

[timshatz]

Comming back, I have not done a route but I am thinking the southern route looks best. Most of the ideas I've already mentioned but I will re-itterate them.

1. Never come out the same way you came in.
2. Crossing Middle Europe (Germany/France) would go right into the teeth of the fighting, heaviest concentration of VVS fighters.
3. Lower concentration of SU forces to the Southern Route (hopefully).
4. Possible to launch strong raid from Italy towards Eastern Europe to get SU attention, 15th Air Force Max Effort?
5. Potential for landing in the hands of friendly civilians greater in Poland than in Germany.

Would go from Moscow to Poland and on to Italy. Used Verona as the landing airfield (not sure this is accurate for 1945 as I went with present numbers, if another field is better, let me know)

Here are the numbers:

Route between UUDD (MOSKVA (MOSCOW), MOSKOVSKAYA OBLAST', RUSSIA) and LIPX (VERONA, VENETO, ITALIA (ITALY)):
Distance along great circle: 1362.7 statute miles, 1184.2 nautical miles, 2193.1 kilometers
Initial true great circle heading: 250.8 degrees (west-southwest)

Flight time at 220 knots: 5 hours 22 minutes