Best medium bomber of WWII?

[Shortround6]

I would like to know more about the tu-2, since I heard it was similar to the pe 2 but had a better performance and payload

It should, it weighed about 50-55% more.
Due to both shortages of engines and factory space it didn't really have much impact on the war until 1944-45, and even then, while successful, it wasn't used in large numbers compared to other Soviet aircraft. Again, not a reflection on the design, it is a result of the numbers available and/or used. About 1/2 of the total number produced were built after the Germans surrendered.

 

[tomo pauk]

It should, it weighed about 50-55% more.
Due to both shortages of engines and factory space it didn't really have much impact on the war until 1944-45, and even then, while successful, it wasn't used in large numbers compared to other Soviet aircraft. Again, not a reflection on the design, it is a result of the numbers available and/or used. About 1/2 of the total number produced were built after the Germans surrendered.

There was no shortage of M-82 engines; Soviets were trying to install it in 1942 in everything promising the good return of investment - Il-2, Pe-2, Yak-7, LaGG-3, Pe-8 - since the Su-2 (the main perspective recipient of the M-82) was cancelled by winter of 1941/42. The 1st Tu-2 were also with technical problems, the main (at least per Russian-language Wikipedia) were the problems with undercarriage, that were rectified by copying the system used on Li-2 /= licence-produced DC-3); internal wiring and lighting was also redesigned. But yes, it took until 1944 for the Tu-2 to matter in ww2.

But, to answer the question - Tu-2 was designed as a bomber from day one, with a decent bomb bay (still nothing special), and was able to carry a few times greater bomb- and fuel-load and gun firepower. Same source as above notes that Tu-2 in engine-out situation was a better thing than Pe-2 in the same situation.

 

[Dimlee]

I would like to know more about the tu-2, since I heard it was similar to the pe 2 but had a better performance and payload

I suggest starting with the Wiki article. And then, if you have time, to Google translate Russian article on Wiki. And if you are interested in the full story from the first prototype, until the post-WWII development, you could Google Translate articles from this source:
Бомбардировщики Второй Мировой
There are several articles in the list.
The first: Туполев ФБ ("103") Фронтовой бомбардировщик.
The last: Туполев ТУ-10 Скоростной пикирующий бомбардировщик


The Tu-2 story is interesting (besides the fact that it was designed by the prisoners de-jure). Most teething problems were resolved and serial production began in April-May 1942 but in October NKAP (Aviation Ministry) ordered to stop. According to the head of NKAP Shakhurin, it was the decision of Stalin and the official reason was the urgent necessity to produce more fighters. Yet this version contradicted other memoirs of Shakhurin himself and of other decision-makers who wrote about the deficit of bombers since spring 1942 and attempts to turn almost every fighter type into a fighter bomber. Ironically, 20 days after the production suspension, a heavy multipage document was delivered to Kremlin - the full report about the frontline tests of Tu-2 (80 a/c produced, 63 a/c delivered to VVS). That report praised the new bomber highly.

 

[Shortround6]

Basically the Russians built about 80 Tu-2s in 1942 and then for various reasons (none having to do with the performance of the aircraft) stopped.
Production didn't start again until well into 1943 and that was at a low rate. 16 aircraft delivered by the end of 1943 and only 1,013 were built (including the 80 in 1942) by the end of the war in 1945.
At the beginning of 1945 one book claims 278 Tu-2s were on strength with the Soviet Air Army Force, 264 of them operational. Two bomber air divisions and one long range reconnaissance regiment were the main users at the time. The Tu-2 made up 9% of the Russian bomber strength at the time.

Another 1,514 aircraft were completed after the war.

 

[Koopernic]

The Tu 2 has one feature that makes it better than the Ju 88/188 and that is an internal bomb bay that can handle full sized bombs allowing the aircraft to maintain high speed. The Ju 88 was a low wing monoplane and this subdivided the bomb bay due to the wing spars. The biggest internal bomb was a 70kg (usually fragmentation type useful for a battlefield). Carrying external underwing bombs would likely reduce speed from 315mph for the Ju 188E1 by 10%-13% for 4 x 250 or 4 x 500 or 2 x 1000.

The low wing no doubt kept the Ju 88 fuselage strong for the 60 degree dives it was designed for. Worth considering that the Ju 88S1 was capable of 600kmh/372mph at 6000m/19700ft without GM-1 nitrous oxide and 610kmh/378mph at 8000m/26200ft with GM-1. Had this aircraft a bomb bay it would have been a difficult target even over Britain. It was however used as a pathfinder where it's bomb bay restrictions weren't too limiting.

Having said that, the Ju 88 was available throughout the war and the Tu 2 barely so. The Ju 388 received a ventral Panier to carry bombs with modest drop in speed.

 

[GrauGeist]

The Soviet's Arkhangeleski Ar-2 held potential, it was fast (for 1940) and was capable of dive-bombing and could carry over 3,500lbs of bombs, but the Pe-2 overshadowed it.

 

[fastmongrel]

The Soviet's Arkhangeleski Ar-2 held potential, it was fast (for 1940) and was capable of dive-bombing and could carry over 3,500lbs of bombs, but the Pe-2 overshadowed it.

There's always the political side of Soviet procurement, some good prototypes got nowhere because of Stalin.

 

[Koopernic]

There's always the political side of Soviet procurement, some good prototypes got nowhere because of Stalin.

It's rare to read about a Soviet design in which the initial designer wasn't consigned permanently to a gulag, or working from one (like Tupolov) or in the case of the project manager for the MiG 3 was actually executed. It was much easier for aeronautical engineer under Hitler it seems. Imagine the Me 210 delays or Me 262 bomber fiasco under Stalin. Willy Messerschmitt was probably lucky to avoid prison over the Me 210 affair but ended up loosing control of his company.

 

[Shortround6]

The Soviet's Arkhangeleski Ar-2 held potential, it was fast (for 1940) and was capable of dive-bombing and could carry over 3,500lbs of bombs, but the Pe-2 overshadowed it.

The AR-2 may be being oversold.
Basically it was an improved SB which first flew in 1934.
Major change was that it got M-105 engines with the radiators in the wings (and much more streamlined nacelles) for a huge reduction drag.
another change was a slightly smaller wing (reduction in span and area)
One book claims that while the max bomb load was 1500kg (without saying how it was carried) the max range with 500kg (1102lbs) of bombs was over 1304 miles (2100km).
However range with 1000kg (2204lbs) of bombs was 621 miles (1000km).
Armament may be in dispute, nose had one gun instead of two on the SB bombers but table still lists four guns?
Weight is within a few hundred pounds of a Blenheim MK IV.
Maybe you could stuff/hang 3300-3500 lbs on it but you aren't going to go very far with an under 15,000lb airplane (or go very fast if the bombs are outside)?

 

[Shortround6]

Worth considering that the Ju 88S1 was capable of 600kmh/372mph at 6000m/19700ft without GM-1 nitrous oxide and 610kmh/378mph at 8000m/26200ft with GM-1. Had this aircraft a bomb bay it would have been a difficult target even over Britain.

HAD the Mosquito used nitrous oxide (Rolls Royce did experiment with it) the Mosquito could have flown even higher and faster than it did while still carrying a useful bombload.

Most of the "improved" Ju-88s fall into a never-never land between reality and "what ifs".

From wiki so corrections welcome JU 388 production

• 6 Ju 388 prototypes, 2 each for J-1, K-1 and L-1
• 20 Ju 388 L-0, including prototypes V7, V8, V30 - V34
• 10 Ju 388 K-0, first batch, including two converted to the Ju 488 V401/V402 prototypes (never flown)
• 1 Ju 388 K-1 manufactured by ATG for static tests in July 1944
• 46 Ju 388 L-1 manufactured by ATG in 1944
• 8+ Ju 388 L-1 manufactured by ATG in 1945
• 10 Ju 388 L-1 (max.) manufactured by Weserflug (WFG), initially planned as K-1

More aircraft and prototypes were planned and partially completed:

• 10 Ju 388 K-0, second batch, some prototypes, partially completed
• 30 Ju 388 K-0, third batch, planned, only few units completed

So a plane with 50-70 examples built is a contender for best medium bomber or WW II?

 

[fastmongrel]

The Ju488 seems an awful lot of plane and engines to carry 3 tons of bombs.

 

[pbehn]

The Ju488 seems an awful lot of plane and engines to carry 3 tons of bombs.

But dive bombing from 30,000 ft ensured complete accuracy.

 

[Mike Williams]

HAD the Mosquito used nitrous oxide (Rolls Royce did experiment with it) the Mosquito could have flown even higher and faster than it did while still carrying a useful bombload.

Mosquitos did use Nitrous Oxide on operations:

http://www.wwiiaircraftperformance.org/mosquito/Cunningham_85squadron_2Jan44-nitrous-oxide.jpg
http://www.wwiiaircraftperformance.org/mosquito/96sqdn_Head_22march44_Nitrous-Oxide.jpg
http://www.wwiiaircraftperformance.org/mosquito/Parker-Rees-96sqdn-13-14April44-N2O.jpg

 

[Koopernic]

Mosquitos did use Nitrous Oxide on operations:

http://www.wwiiaircraftperformance.org/mosquito/Cunningham_85squadron_2Jan44-nitrous-oxide.jpg
http://www.wwiiaircraftperformance.org/mosquito/96sqdn_Head_22march44_Nitrous-Oxide.jpg
http://www.wwiiaircraftperformance.org/mosquito/Parker-Rees-96sqdn-13-14April44-N2O.jpg

Yes, I learned about these from you site years ago. These were Mosquitos with single stage Merlins (Merlin 24?) . What was there speed advantage over a Ju 88S1. I would assume about 400mph over 378mph (about 22mph or about 6%)

Do you have any data on what the speed of these hotrod Mosquitos was? I noted the pilots engaged the Nitrous at quite a low altitude.

The Ju488 seems an awful lot of plane and engines to carry 3 tons of bombs.

It was to do it at 48500ft and 3000kg is was more than a B17.

I think the internal bombload of the Ju 388 and early Ju 488 V401 was both about 2000kg (maybe 3000kg if armour piercing bombs) but the Jumo 222 version of the Ju 488 it was 5000kg

But dive bombing from 30,000 ft ensured complete accuracy.

Probably 44000ft as the service ceiling with BMW 801TJ was estimated at 48500ft (Black Cross Publications Ju 288/388/488)

I imagine an electronic blind bombing aid would be used and the main source of inaccuracy would be high altitudes winds the bombs would experience mid way in their fall.
25mph side wind produces about 85ft error from 20,000ft. There is always the possibility of a guided weapon.

So a plane with 50-70 examples built is a contender for best medium bomber or WW II?

The Ju 388 was essentially still a Ju 88/188 with pressurisation. It served from 1939 all the way to 1945 and in the form of the Ju 388 would have still been competitive.

 

[Mike Williams]

Yes, I learned about these from you site years ago. These were Mosquitos with single stage Merlins (Merlin 24?) . What was there speed advantage over a Ju 88S1. I would assume about 400mph over 378mph (about 22mph or about 6%)

Do you have any data on what the speed of these hotrod Mosquitos was? I noted the pilots engaged the Nitrous at quite a low altitude.

Here's more docs on performance of Mosquitos using Nitrous Oxide.
Power Boosting By Nitrous Oxide
Injection of N2O into Merlin 25 engine fitted to Mosquito XIX aircraft
Flight Tests of N2O Power Boosting Mosquito XIII Merlin 23
Fwiw, Nitrous Oxide - Ricardo & Co.

 

[pbehn]

Probably 44000ft as the service ceiling with BMW 801TJ was estimated at 48500ft (Black Cross Publications Ju 288/388/488)

I imagine an electronic blind bombing aid would be used and the main source of inaccuracy would be high altitudes winds the bombs would experience mid way in their fall.
25mph side wind produces about 85ft error from 20,000ft. There is always the possibility of a guided weapon..

This is fantasy, just adding black crosses to a plane that didn't fly in black cross publications doesn't change the laws of physics. A three ton bomb load isn't much in strategic terms, taking three tons of bombs to 48,000 ft is a dream with 1944 piston engine tech. You cannot hit anything dropping a dumb bomb from 48,000 ft over Europe and no guided bomb could either.

 

[GrauGeist]

It's rare to read about a Soviet design in which the initial designer wasn't consigned permanently to a gulag, or working from one (like Tupolov) or in the case of the project manager for the MiG 3 was actually executed.

Let's not forget Lavochkin, who was saved from the "Stalin Flu" by the nose of a Su-2.
Then there was Kalinin, who did get the "Stalin Flu"...

 

[Vincenzo]

The AR-2..
One book claims that while the max bomb load was 1500kg (without saying how it was carried)

the 1,500 kg load was one 500 kg in the bay and one each under the wings, or two 250 kg in the bay and two each under the wings
it can also load 8x100 internal and 4x100 external

 

[ThomasP]

Hey Koopernic,

Because I am an AR type, and as a matter of passing interest:

The below assumes a falling time of 35.35 sec from 20,000 ft release height, with an average acceleration due to gravity vs aerodynamic drag of 32 ft/sec^2.

If the dropping aircraft has a sideways vector of 25 mph at time of bomb release, then the point of impact due to this sideways motion would be 1296 ft off to the side of the aim point.

If the aircraft has 0 sideways vector at time of drop, then the bomb's point of impact would be about 648 ft (assuming the bomb has a 25 mph sideways velocity at impact).

If we add the minimum practical optical line of sight error (plus or minus 1/2 degree) for the (pick any bombing system you feel was the best) bombing system (ie aircraft-bomb sight combination) that saw service in WWII, you have to add +/-174 ft to the point of impact. WWII blind bombing systems were significantly less accurate in terms of minimum achievable aiming error. The reason I say minimum practical achievable is that there really was no practical method of aircraft-bomb sight calibration that could reliably achieve more than plus-or-minus 1/2 degree LOS error. (As far as I know. If anyone has better information please let me know.)

 

[Dimlee]

The AR-2 may be being oversold.
Basically it was an improved SB which first flew in 1934.
Major change was that it got M-105 engines with the radiators in the wings (and much more streamlined nacelles) for a huge reduction drag.
another change was a slightly smaller wing (reduction in span and area)
One book claims that while the max bomb load was 1500kg (without saying how it was carried) the max range with 500kg (1102lbs) of bombs was over 1304 miles (2100km).
However range with 1000kg (2204lbs) of bombs was 621 miles (1000km).
Armament may be in dispute, nose had one gun instead of two on the SB bombers but table still lists four guns?
Weight is within a few hundred pounds of a Blenheim MK IV.
Maybe you could stuff/hang 3300-3500 lbs on it but you aren't going to go very far with an under 15,000lb airplane (or go very fast if the bombs are outside)?

In my opinion, Ar-2 could become (at least) a good interim frontline bomber until Tu-2.
Ar-2 could dive well, as mentioned by GrauGeist, also with max bombload of 6x250kg or 3x500kg. Interesting to note that some diving equipment was copied from Ju 88. Carried more than Pe-2, was easier to fly - even easier than SB-2, lower landing speed, etc.
It has lost the competition to Pe-2 due to somewhat lower speed. Was it so important in the real war? I don't think so, Pe-2 without the escort was very vulnerable anyway. Another advantage of Ar-2: former SB-2 pilots could begin to operate them quickly.
I'd place Ar-2 in the category of "I coulda' been a contender" aircraft. Promising but not allowed to realize its full potential due to external circumstances. Same as Tu-2, by the way.