VVS alternatives for 1938-42?

[Dimlee]

I've read whenever Lend lease was discussed with Stalin, he always asked for B-29s on his list of aircraft.

According to Russian sources (Kotelnikov, Sobolev), the first request for B-29 was sent by Moscow in July 1943.

 

[GrauGeist]

Instead of the P-47, would it be possible to bump up the time frame of the La-7 any?
The La-7 debuted in 1944, roughly the same time the P-47D appeared (late '43, early '44).

 

[tomo pauk]

IIRC the performance of early La-7s was in the ballpark with last La-5FNs.
The ASh-82FN engine took until 1944 to mature.

 

[warbirdbuff]

Theory about USAF opposing the drop tank idea was probably true for era before 1941.
In one of Greg's videos, he spins up a theory that P-47 was precluded by the higher ups from having drop tanks as late as 1943, going as far as accusing the USAF brass for rather sending the B-17 crews in harms way, than to have P-47s using the drop tanks that were supposedly in the UK by thousands. We've discussed that video in the 'Aviation' forum here some time ago, IIRC conclusion is that Greg went well off the mark there.

I can't speak to that. It wasn't a video I saw, it was just an average website. (And my browser history, if it's there, isn't showing it... Neither did I bookmark it, not expecting to need it again {my mistake } Nor is Google any help...) I don't recall it going so far as saying the drop tanks were "in the thousands", just that the concept existed & was consciously rejected, & had been deliberately downplayed ("ignored" & "suppressed" are too strong, but it was in that vein) into '43. It also reproduced documents that appeared to show just that.

That said, my recall may be faulty...

 

[Darthtabby]

5. Production of DB-3F/Il-4 is stopped at the end of 1941 completely. Replaced by lend leased B-25s in VVS and by A-20 in the Navy.

5 & 7 - With Tu-2/ANT-58 in early service, plus availability of Western bobers, the need for the Il-4 is indeed much diminished.

Do those aircraft have the range to do the DB-3F/Il-4's job? I'd been reading the second volume of Gordon Yefim and Dmitri Khazanov's Soviet Combat Aircraft of the Second World War as research for a game mod I'm helping with and the DB-3's range is heavily emphasized. Not only in terms of capability, but that the DB-3 and DB-3F apparently accounted for 86% of the aircraft in Soviet Long Range Aviation on the eve of the war.

The book notes that the DB-3F had a range of 3500km (2187.5 miles) with a 1000kg (~2200 pound) bomb load. That dropped with bigger engines and increased weight, but could also increase with additional fuel capacity and more economical engine settings (for instance a data table lists a 1940 DB-3F as having a range of 3300km with M-88 engines, while a Il-4 with increased fuel capacity could apparently do 3585km at 340km/h and 4265km at 250km/h).

Looking at B-25 specs on Joe Baugher's pages most variant list a range of 1500 miles (2400km) or less. The exception is the B-25B which lists a range of 2000 miles (3200km). Admittedly that's with a 3000lb (~1360kg) bomb load and likely higher cruise speeds. But again that variant appears to have notably longer range then the others.

 

[Dimlee]

Do those aircraft have the range to do the DB-3F/Il-4's job? I'd been reading the second volume of Gordon Yefim and Dmitri Khazanov's Soviet Combat Aircraft of the Second World War as research for a game mod I'm helping with and the DB-3's range is heavily emphasized. Not only in terms of capability, but that the DB-3 and DB-3F apparently accounted for 86% of the aircraft in Soviet Long Range Aviation on the eve of the war.

The book notes that the DB-3F had a range of 3500km (2187.5 miles) with a 1000kg (~2200 pound) bomb load. That dropped with bigger engines and increased weight, but could also increase with additional fuel capacity and more economical engine settings (for instance a data table lists a 1940 DB-3F as having a range of 3300km with M-88 engines, while a Il-4 with increased fuel capacity could apparently do 3585km at 340km/h and 4265km at 250km/h).

Looking at B-25 specs on Joe Baugher's pages most variant list a range of 1500 miles (2400km) or less. The exception is the B-25B which lists a range of 2000 miles (3200km). Admittedly that's with a 3000lb (~1360kg) bomb load and likely higher cruise speeds. But again that variant appears to have notably longer range then the others.

I think that an extra 1,000 km or so is irrelevant in this case. After the demise of the DBA (long-range bomber aviation) in 1941, there was no long-range strategy in its pre-war meaning - with deep penetration of the enemy home air space, massive attacks of strategic targets, etc. Newly created ADD (long-range aviation) was given many tasks where 3500km was hardly needed. For occasional attacks of the targets in the Reich's territory, there were Pe-8s. B-25 was superior in terms of pilot's comfort, radio and navigational equipment, autopilot, reliability, could fly with one engine off, etc. In my opinion, even Li-2 was better than Il-4 for most of the tasks in ADD.
Aircraft types in ADD on 10th May, 1945:
DB-3 0
Il-4/DB-3F 553(80)
Yer-2 101(37)
TB-3 39(0)
TB-7/Pe-8 32(14)
Li-2 593(59)
B-25 357 (31)
Non-serviceable aircraft in brackets. Probably, Far East regiments not included.
Source: Sovetskay Aviatsiya v Velikoy Otechestvennoy Voyne v tsifrakh (Soviet Aviation in the Great Patriotic War in figures, 1962).

 

[Dimlee]

By the way, what is the game? (if this is not classified).

 

[Darthtabby]

It's for a Hearts of Iron IV mod called ULTRA. HOI IV is actually a grand strategy game so its air combat model is mostly abstract and stats based, but I still want to provide the person coming up with the airplane stats with good data to work off of (they've cooked up some formulas that convert a large array of data into in game stats).

I'm a bit surprised by the suggestion that a transport conversion like the Li-2 would be a better choice then the Il-4. Airpages.ru does suggest the Li-2 was more comfortable and easier to fly. But my main source for Soviet bombers (the second volume of Yefim and Khazanov's Soviet Combat Aircraft of the Second World War) seemed to indicate that the DB-3 series had generally good handling (and it did point out handling issues with other Soviet aircraft such as the Pe-2).

Early in its successful like the DB-3 gained the high appreciation of its pilots. Particularly notable were its ease of take-off, rapid climb, good stability without any hint of yaw, steady level flight (which made it a good bombing platform), tight turns with 40° to 60° of bank, and easy landing approach. It had no dangerous tendencies such as rapid loss of speed, wing stall and arbitrary ballooning during landing. The DB-3 also had good single-engine capabilities, and at a normal flying weight of 15,432lb (7,000kg) could climb and turn in both direction on one engine. However, pilots noted a lack of longitudinal stability owing to the generally accepted aft cg position.

That's for the original DB-3, but there's little indication of handling problems with the DB-3F at least until weight gain caused a shift in CG that was corrected with modifications.

Take-off and landing performance was considerably improved. The glidepath was steeper, shock absorption was softer, and braking was more effective, thus improving taxying. In the resulting report on the state tests it was noted that the DB-3F was considerably better than the DB-3 for bombing missions. The newly developed canopy ensured excellent working conditions for the navigator, facilitating target location and defensive fire.

The fourth crew members and the armoured protection for the gunner considerably displaced the aeroplane's cg, upsetting longitudinal stability and controllability. This was rectified in the machines built from the summer of 1942, which had a newly developed detachable wing section with an 'arrow' along the leading edge which moved the cg forward relative to the aerodynamic chord. The detachable part of the wing with the 'arrow' had a new aerodynamic profile which increased the relative thickness by 10%, and a composite structure of metal spares with wooden ribs and skin. The thicker detachable wing profile and the displacement of the lower ribs outside the skin (this structure formed a so called 'rib-skin') permitted the installation of three protected fuel tanks instead of one, increasing the total weight of fuel by 2,502lb (1,135kg) compared with the production DB-3F).

Yefim and Khazanov do indicate that there were problems with the M-88 engines that took considerable time to resolve even on the B model (p.101) though they later favorably compare the M-88B's reliability to that of the M-82, M-89, and M-90 (p.103).

In contrast to the impression I got from Yefim and Khazanov some of the pilot quotes in this blog post from vvsairwar.com seem to indicate the Il-4 was a sluggish and difficult airplane. On the other hand they also indicate that it had a much appreciated ability to withstand battle damage. One pilot is also quoted as preferring the Il-4 over the B-25 due to the Il-4's ability to fly high, though converting the quoted 7800 meters yields a figure of 25,740 feet -not much higher then the 23,500 and 24,000 feet I've seen for B-25 variants. (Interestingly Soviet Combat Aircraft of the Second World War also indicates that Soviet bomber pilots valued high altitude performance, as the switch to M-105 variants optimized for low altitude on the Pe-2 was apparently unpopular due to the reduction in high altitude performance.)

 

[Dimlee]

Gordon (the last name of Yefim Gordon) and Khazanov are good authors. But I don't remember any of them doing a deep study of the DB-3/Il-4 family. I might be wrong.
Actually, when I search for information on this aircraft in Russian I can find just two books, by Ivanov and Kotelnikov, published in 2004 and 2009, respectively.