IL-2 doesn't suck as bad as the SU-2 (1 Viewer)

[Shortround6]

Suggested by Dimlee in another thread.


Now to get started for our Wikipedia afficandos the specs given in Wiki are for the M-82 (ASh-82) and only about the last 60 built out of around 900 had that engine. the rest pretty much used the M-88 which was the developed/licensed Gnome- Rhone 14K engine. Speed was about 233mph at sea level and about 290 mph at altitude for production planes (In Soviet fashion the prototypes were 20-30mph faster).

It did have four 7.62mm machine guns in the wings with a high rate of fire so was rather useful for strafing but the listed bomb load, while true, needs a bit of explaining, the internal bay was good for 880lbs (four 220lb bombs ?) but external racks were needed for another pair of 220lb bombs to reach the listed max of 1320lbs and external storage means less speed/range.
Various rocket installations were used. which would also hurt speed. '

These planes were, on occasion, flown with a pair of 550lb bombs on the outside racks.

One reason for it's "success" may be that it was used, at least partly, in the less hotly contested areas of the front in the early part of the invasion. This changed as the war went on.

The IL-2 did have the cannon in the wings along with the four machine guns making it a more potent strafer. Bomb and rocket loads weren't much different. The SU-2 was sturdy but not particularly well protected (at least to anywhere near the extent the the IL-2 was) although it was one of the first Russian aircraft to have self sealing fuel tanks.

 

[GrauGeist]

If I recall correctly, the pilot and rear gunner (in that goofy turret) had armor. While it wasn't as profound as the IL-2's armor, it was roughly 11/32" and could protect against ground fire to a certain degree.

 

[Freebird]

Suggested by Dimlee in another thread.


Now to get started for our Wikipedia afficandos the specs given in Wiki are for the M-82 (ASh-82) and only about the last 60 built out of around 900 had that engine. the rest pretty much used the M-88 which was the developed/licensed Gnome- Rhone 14K engine. Speed was about 233mph at sea level and about 290 mph at altitude for production planes (In Soviet fashion the prototypes were 20-30mph faster).

It did have four 7.62mm machine guns in the wings with a high rate of fire so was rather useful for strafing but the listed bomb load, while true, needs a bit of explaining, the internal bay was good for 880lbs (four 220lb bombs ?) but external racks were needed for another pair of 220lb bombs to reach the listed max of 1320lbs and external storage means less speed/range.
Various rocket installations were used. which would also hurt speed. '

These planes were, on occasion, flown with a pair of 550lb bombs on the outside racks.

One reason for it's "success" may be that it was used, at least partly, in the less hotly contested areas of the front in the early part of the invasion. This changed as the war went on.

The IL-2 did have the cannon in the wings along with the four machine guns making it a more potent strafer. Bomb and rocket loads weren't much different. The SU-2 was sturdy but not particularly well protected (at least to anywhere near the extent the the IL-2 was) although it was one of the first Russian aircraft to have self sealing fuel tanks.

If I remember correctly, SU-2 production ended, the factory switched over to TU-2?

 

[Dimlee]

Il-2 vs Su-2 was one of those "Great Debates" which lasted for years in the post USSR Russian language aviation history circles.
(Probably the debate is still on, I stopped following some years ago.)
Not being the historian or aviation expert myself, I read and learned a lot in articles, threads, posts, etc.
As I have no access to my old sets of bookmarks and files collection now, let me to summarise just what I remember.
1. Pilots opinions in 1941-1942 were mixed about both aircraft. Both were loved and hated, just for different reasons. Both often were sent to the battle in 1941 without escorts and with little or no recon information. Both were vulnerable to small calibre AAA at low altitudes.
2. Il-2: better armour protection of the pilot and of the engine. Su-2: rear MG and one more pair of eyes - from the day one, dual controls (saved lives and helped in training), reliability of radial engine, "lighter" controls, better agility, navigational instruments, heated cockpit.
3. Il-2: 20-mm cannons and (probably) more diverse rockets weaponry. Su-2: slightly larger bomb load, better bombing accuracy, ability to bomb from higher altitudes.
4. Il-2: less demanding for rookie pilots. Was it really an advantage is debatable. Probably it was under some circumstances.
5. Critical point in Su-2 history - evacuation of the main factory from Kharkov in October 1941 and termination of barely started production in Kuibyshev in Nov (Dec?) 1941. Critical point in Il-2 history: telegram of Stalin in Dec 1941 which said that Il-2s were needed for the Read Army immediately as "bread".
6. Personalities of chief designers: Sergey Ilyishin excelled in "politics", well connected, member of the Party since 1918, veteran of the Civil War. Pavel Sukhoy - did not took part in the Civil War, not a Party member until 1930s, allegedly disliked by Stalin after Sukhoy's refusal to head modernisation of Pe-2 after the death of Petlyakov.
7. In my opinion overall, there was demand for both aircraft. Il-2 was good for one and only "shturmovik" role. Su-2 has never been a "flying tank", but it was more versatile: bomber, recon and photo recon, artillery spotter, night and low visibility operations.

Edit:
just to add this
Most ignored combat aircraft of ww2

 

[Shortround6]

The SU-2 is also one of those "what if" planes.

It's reputation, for good or ill, stands on the planes produced in 1940/41 which means it saw only minor improvements.
Never got the 12.7mm out the back that many claimed cut the losses of the PE-2 and the IL-2 (to an even greater extent as it had no 7.62 to begin with).
The last 40 (?), a drop in the bucket for Russian aircraft, got the 1400-1540hp M-82 engine but there is no real record of their combat performance, the rest had 1000-1100hp M-88 engines.
There may have been room for considerable improvement in the airframe but there are only so many M-82 engines to go around.

It may have been harder to fly than the IL-2, this is a relative term, it may not have been a difficult plane to fly as most planes go but the IL-2 seems to have particularly easy. A blessing and a curse. You could put planes into the air with low time pilots, but low time pilots are going to get shot down in large numbers.
The SU-2 seems to have lavashley equipped compared to some other soviet aircraft. Which means expensive. The fact that the rear seat man had at least rudimentary controls meant at least a few more could get home with a disabled pilot than the IL-2 could.

But we are comparing an 1100hp plane to a 1700hp plane and without switching to the M-82 engine there is only so much the SU-2 was going to be able to do.

 

[tomo pauk]

...
The last 40 (?), a drop in the bucket for Russian aircraft, got the 1400-1540hp M-82 engine but there is no real record of their combat performance, the rest had 1000-1100hp M-88 engines.
There may have been room for considerable improvement in the airframe but there are only so many M-82 engines to go around.
...

Soviets have had a surplus of M-82 engines in 1942, a reason why there was a race to re-engine most of the 1-st line aircraft with it: Il-2, future Tu-2, Pe-2, Yak-7, LaGG-3.

 

[Shortround6]

There may have been surplus but how long did it last?

They built about 58,000 during the whole war and if you try to replace (or supplement) IL-2 production with thousands of M-82 SU-2s in 1942-43 where are you?
Neither engine had a long overhaul life so you do need a fair amount of spares even if many aircraft are shot down before their engines hit their service life limit.

Part of the "race" to use the M-82 was because the Soviets don't have good alternative engine.
The M-88 has hit it's limit (that missing the center bearing on the crankshaft thing),
The M-105 was also hitting it's limit, they were already sacrificing engine life for the power boost it did get.
The M-106 and 107 were being tried but were years away for actual service ( how long was not known but betting your design organization on those engines was not a good career move)
The M-71 remained in the experimental stage for years (although trialed in a number of aircraft)
The AM-35/37 was as we see it, a large engine, good for either low altitude or high altitude but not both at the same time. Also not the most reliable thing going.

If you wanted to survive as a design chief in Stalin's russia the M-82 offered a good combination of power, size/weight and reliability. If you got your design in first you had a better claim to what production there was compared to a designer who showed up late with his aircraft. Not a guarantee, but a better chance.

 

[tomo pauk]

In 1942, Soviets produced 40 Su-2, 79 Tu-2, 21 Pe-8, 1129 La-5 = 1569 engines needed. (asumed all of them use M-82)
Produced in same year: 3962 of M-82/ASh-82/ASh-82F engines. I'd say that 1400 of surplus engines is a quite a number for the Soviets in 1942.
But, at any rate, I'd install the M-82 engines in fighters in any given month of ww2.

 

[Shortround6]

Any plane produced in Jan or Feb of 1943 probably had it's engine built in Nov or Dec of 1942. Getting engines crated, loaded on railroad cars and shipped to the airframe factories, Pames on the production lines with engines installed but not completed.
With Aircraft factories hundreds of miles apart (if not over a thousand) a temporary surplus of engines at one factory cannot be sent to another factory quickly or easily. Even if the factory with a temporary surplus would give up it's engines.

Yes there probably some surplus engines in 1942 but not as many as the comparison of engines to airframes built would suggest.

 

[tomo pauk]

...

Yes there probably some surplus engines in 1942 but not as many as the comparison of engines to airframes built would suggest.

Actually, I'm convinced that egine surplus was even more prononuced in 1st half of 1942. Decision to cancel the Su-2 was made before 1942, months before the main user of M-82 engines (La-5) flew as prototype. VVS made their decision because of how they judged the Su-2 was, not beacuse there was no M-82 engines to install on it. Thus a flurry of prototypes to somehow put into a good use of a good engine.
In 1941, 411 of M-82 engines was produced.

 

[alejandro_]

A small point. The fact that SU-2 had a radial engine did not make it better protected than Il-2. Yes, the radial engine is more resistant to damage but in the Il-2 the AM-35 was very well protected inside a "capsule". The liquid cooling meant that no large open frontal area were necessary. This is one of the reasons why the Il-2 with M-82 engine did not go ahead.

 

[GrauGeist]

The reason why the ASh-82 was considered for the IL-2, was because of potential shortages of the AM-38.

The radial was never used both because the AM-38 shortage never materialized and the ASh-82 was earmarked for the La-5.

 

[Dimlee]

VVS made their decision because of how they judged the Su-2 was, not beacuse there was no M-82 engines to install on it.

I have concluded from those endless discussions years ago that the decision, or probably the chain of decisions, was made not in VVS but in the political corridors of Moscow and Kuibyshev (where production was relocated and where some of Government and Party departments were evacuated).

At last I purchased this book of Dmitriy Khazanov which sat in my wish list for long time:
https://amzn.to/2EG3NwN

I'll read it soon and probably will be able to contribute more to the thread.

 

[Shortround6]

Thank you.

 

[Dimlee]

OK, I read that book.
https://amzn.to/2EG3NwN
Unfortunately, it does not add much to the information about Su-2 development and its deployment in 1941-1942 besides what was published already since early 2000s. Statistic data is patchy, poorly arranged and without attempt to make serious analysis... well, this is typical issue of many Soviet and post Soviet military publications. Not the best work of D.Khazanov, unfortunately.

On the bright side, there is detailed narrative of pre-war history of Su-2 and prototypes and interesting (yet not systematized) records of combat operations.

Below is the information which I find interesting in the context of this thread.

1. In 1941.
Three regiments in Zapadny (Western) regional command. June 21st, 1941: 75 aircraft and 126 crews available, just 25 crews "ready for combat".
Extremely intensive operations end June-early July 1941. Probably the most intensive among all bomber types except SB. Up to 40 and more flights per day. Some regiments have lost all aircraft and were withdrawn to the rear after 10-15 days. Exception: Odessa region where Su-2 were used rarely until middle of July when enemy forces began to cross Dniester river.

2. Production in war time.
Problems started in July 1941 after evacuation of Zaporozhye factory (one of three producing Su-2). Two other factories (Kharkov and Dolgoprudnensky) were relocated in October 1941. Before that, Kharkov's production was already limited because all stock of M-89B engines was taken out and shipped to Komsomolsk-on-Amur (Far East of USSR) for DB-3F bombers.
Attempts to resume production in new place (Molotov) began in November 1941. The plan was to create new large factory on the base of equipment of several plants relocated from the occupied territories. Apparently, good idea at the wrong time and wrong place. Lack of equipment (delayed and lost during relocation), deficit of workforce (less than 50% of required)… To make things worse, M-82 engine blueprints were lost during transportation.
GKO (State Committee of Defence) held the conference on 19th November 1941 and issued the resolution with two main points:
a) M-82 engine to be installed only on TB-7, project 103 (future Tu-2), IL-2 and DB-3F.
b) Factory in Molotov to stop all works related to Su-2 and to start production of IL-2 with M-82 engine. (Later the factory was allowed to complete production of small batch of Su-2 from the kits and spare parts already in the stock).
Results of this resolution?
TB-7(a.k.a. Pe-8). Adaption for M-82 took several months. Test flights began only in April 1942 and completed in October 1942. Just one Pe-8 with M-82 was produced in 1942.
DB-3F. After all tests and trials in 1942-1943, M-82 engine was not accepted.
Project 103 (Tu-2). 80 airplanes were produced in 1942 before all works were stopped by another resolution of GKO. Resumed at the end of 1943.
Il-2 with M-82 engine. Blueprints were not ready until end of December 1941. Trials began on 20th Feb 1942. Ordered in production 28th Mar 1942. Ordered to stop production and to give remaining stock of M-82 engines for the LaGG fighters modernisation – 26th Apr 1942.

5. About losses.
66th Division reported numbers of flights per combat loss in 1941: Pe-2 - 32, SB - 8, Su-2 - 71.
2nd Army close air support aviation (1 regiment of Su-2 and 3 regiments of IL-2) statistics during German offensive near Voronezh, summer 1942, total/serviceable:
27th June. IL-2 53/36. Su-2 26/16.
01st July. IL-2 41/11. Su-2 22/14.
270th Division attrition rate in Jul-Aug 1942, flights per total loss (all reasons): Su-2 – 80, Pe-2 – 20.
Reserve regiments and training centers in 1941-1942: Su-2 safety record was 25%-30% (in terms of flights per accident) better than of Pe-2 and IL-2.

6. Trivia.
Total production: 893 according D.Khazanov or 910 according to Sukhoi Company. In service until January 1944.
Su-2 and Curtiss O-52 were the only artillery spotters of VVS in 1942-1943 (not counting less successful attempts with Yak-7) . When number of Su-2 dwindled, the only replacement available was IL-2 and it was not ready for that role.
M-82FN engine which brought success to La-5 fighter in 1943, have been tested by Pavel Sukhoi team on Su-2 extensively during summer 1942.
Not less than 7 different engines were tested on Su-2 in 1941-1942 besides already installed (M-87B, M-82, M-88(B)) on airplanes in operation. So, while denied from the further production, the type served as "a flying laboratory".

I wish we have more data from archives to make comparative analysis of operational effectiveness of Su-2 and IL-2. Until then, I refrain from final conclusions.