Scherbakov Shche-2, Polish People's Army, March 1945, Broplan 1/72 vacu

[JWM]

Hi,

Within "Anything but injected" GB I have just finished the Shcherbakov Shche-2. This was a light transport and parachute trainer,  produced near end of WW2 in moderate massive amounts of 550 machine build. Five of them were shifted from March 1945 to Polish communist state army co-belligerent with Red Army (Polish People's Army). They were based on Ułęż airfield near Dęblin in central Poland and were used for paratroopers training. More on this type here (https://en.wikipedia.org/wiki/Shcherbakov_Shche-2 ).

Recently a set of photos and color of this machines were published in a monograph "Polish Wings 28".  There was an article showing some of those photos in journal Aeromax. Recent findings about colors in which Polish Shche-2 were painted are that it was AMT-11/AMT-12/AMT-7. 

The model is Broplan vacu (1/72) which hase few details as injected parts. Since Shche-2 used the same "power egg" like Polikarpov Po-2/U-2 (Shvetsov M-11 engine)  i decided to improve a bit kit by featuring it with resin copies of engines fro, modern ICM Po-2 kit.  Actually the Shche-2 was strongly underpowered with those two small engines and  capability to lift 2 crew members and 16 paratroopers, having wingspan of 20.5 m... So it was a kind of a kite rather... 

The main wheels and oleos I used from a kit of La-5, BTW exactly like it was done in a real thing.

The WIP is here: 

 

Here is the machine:

 

Comments welcome

Regards

Jerzy-Wojtek

 

 

[Vesa Jussila]

Once again type that I have ever heard. I need to get more local books.

[occa]

As usual you build another interesting obscure type, simply love your result :)
'
Btw Jerzy, can you write me an email ?
I've lost your email address. I have a question if you maybe can locate a source for a kit from a Polish manufacturer I am after.
 

Cheers, Martin

[JWM]

34 minutes ago, occa said:

As usual you build another interesting obscure type, simply love your result
'
Btw Jerzy, can you write me an email ?
I've lost your email address. I have a question if you maybe can locate a source for a kit from a Polish manufacturer I am after.
 

Cheers, Martin

Martin, thank you. I've just sent you e-mail. What kit do you need?  Some old Polish productions  are hard to get even in Poland..

 

1 hour ago, Vesa Jussila said:

Once again type that I have ever heard. I need to get more local books.

Thanks! I will try to do this again  

About local books - This Polish Wings no 28 is currently available, you can follow this series, it is in English -  if you are interesting in more info on some rarities...

Cheers

J-W

 

 

 

[occa]

Dear Jerzy,
I just wrote you back, it's an 1/72 Ardpol kit I am after, yes I know it is highly unlikely ...

Cheers,
martin

[TheyJammedKenny!]

This is a handsome finish!  I'd never seen one in this camouflage pattern before, however, as most of the photos I'm familiar with appear to be in Soviet Khaki and light blue undersides.  To me, it's a strikingly modern-looking airframe, undermined--unfortunately--by the weak engines.  I can't believe they could stuff 16 paras in this machine!  That would have been a tight fit, considering that the Valetta, a much bigger design, was designed for only 20!  

 

I think Poland had a number of lend-lease C-47s after the war that allowed her to maintain some semblance of real "szturmi desantowi" forces.

 

Alex

[JWM]

Alex, thank you.

For me the colors were also a surprise for me. Suddenly  I have to decide which exactly paints I have to use as AMT 11/12/7.  When I was starting work I was also used to old concept brown/green scheme and I was thinking that it should be three colors scheme: sand, green, black.  You may noticed it in my build thread that I was really surprised when I carefully read the recent monograph on Shche 2 and found out the concept of a fighter scheme on it....

This is really hard to believe, that this machine was able to fly with 18 (2 crew +16 paras) people on board! With only 280 HP (or even less, 230 HP, there are discrepancy in reported data on power of used Shvetsov M-11 variant). Given, that the airplane, which later took over duties of Shche 2 in Red Army was An-2, having 1000 HP and taking only 9 people.  This was a result of apparent shortage on mid power engines in USSR in WW2.  I've read thet they were intending to use here German Argius engines, but ther number of them captured in field was to small and they were not able to start the own production of a copied engine. There was no modern engine in Soviets in class of some 300-500 HP needed here in normal standards for this size of airplane. 

Indeed Poland had some C-47 and Lisunov Li-2 after the war but they were perhaps too precious (or to costly in use) for a role of lifting up paratroopers several time a week...The construction of this machine was very light, so also delicate and Shche-2 were phased out in Poland in 1947, a bit longer were in use in Yugoslavia (I have found in net a nice photo of a post war all silver Shche with Yugoslavian insignia)  and in USSR till mid 1950s. 

Regards

J-W

 

[KRK4m]

On 4/11/2021 at 6:16 PM, TheyJammedKenny! said:

I can't believe they could stuff 16 paras in this machine!  That would have been a tight fit, considering that the Valetta, a much bigger design, was designed for only 20! 

 

On 4/11/2021 at 8:06 PM, JWM said:

This is really hard to believe, that this machine was able to fly with 18 (2 crew +16 paras) people on board! With only 280 HP (or even less, 230 HP, there are discrepancy in reported data on power of used Shvetsov M-11 variant). Given, that the airplane, which later took over duties of Shche 2 in Red Army was An-2, having 1000 HP and taking only 9 people. 

 

Let me, gentlemen, tweak these numbers a little. Tales of a brilliant plane with a total power of 240 (even if it were 280) hp carrying 16 paratroopers should be put on the shelf with the works of H. C. Andersen and the Brothers Grimm. There has never been such a machine, nor has anyone (yet) constructed a perpetual motion machine.

The arithmetic is inexorable - empty (as the Russians say: dry) Shche-2 weighed 2,240 kg, and after filling the oil system (40 liters) - 2,270 kg. Two crew members average 150 kg, with service parachutes - 180 kg. We already have 2,450 and the fuel tanks are still empty. The design take-off weight of Shche-2 is 3,400 kg, the maximum allowable when operating from a grass airfield - 3,600 kg, and from a concrete runway - 3,700 kg. These are the facts. Thus, the sum of the payload and the fuel weight in these three configurations amounts to, respectively: 950, 1,150 and 1,250 kg.

Assuming the most convenient option, 16 paratroopers would have to weigh 1,250 kg, i.e. one paratrooper - 78 kg. Of course, with a 15 kg parachute on the back, a helmet, boots, and a suit. Perhaps it would be possible to assemble such a team of 16 men, 60 kg each, but the plane still has no fuel ...

So theoretically Shche-2 could take 16 soldiers, but without parachutes and even without personal weapons. So troops, not paratroops. In addition, it would have to operate from a concrete runway and have up to half the fuel supply, the maximum weight of which was 370 kg.

Now let's count it the other way: we operate from a grass airfield (war conditions) and with a full 370 kg of fuel. We have 580 kg left on the load (780 kg under overload conditions). This means 7-9 paratroopers without weapons (e.g. liaisons with the guerrilla units) or 6-8 with assault weapons. And these are the realities.

In fact, Shche-2 was not a true plane. It was a powered transport glider, capable of take-off on its own and flight at a thin limit of aerodynamic efficiency. With full load, it had a climb speed of 230 ft/min, i.e. a practical ceiling of 8,000 ft was reached after 40 minutes of flight (i.e. after covering 50 miles from the take-off site). With normal load, the rate of climb was dizzying 300 ft/min, and the practical ceiling of 10,000 ft was reached "already" after 35 minutes of flight. The maximum speed was 95-100 mph, but the stall speed (thanks to the huge "kite" of 700 sq ft wings) was only 40 mph. Admittedly, the take-off run at normal take-off weight was only 900 ft, but (due to the huge power loading of 35 lb/hp) the next 1,400 ft was necessary to climb the 50 ft obstacle - not often enough when taking off in a forested area. Much better (thanks to low wing loading of 11 lb/sq ft) was landing performance - the landing run was only 500 ft, and 1,300 ft with the descent from a 50 ft obstacle.

Summing up, one should believe in the parameters specified in the technical conditions assigned to Shcherbakov as the starting point. In wartime conditions, the plane was to deliver to the nearby front airfields two VK-105 engines (570 kg each) for the Yak-1/3/7/9 and LaGG-3 fighters. It was necessary because Klimov engines had a lifetime of 100 hours, which in practice was enough for 2 months of operation. Although most of the Soviet pilots were killed during their first 2 months of frontline flying, some of them managed to exceed the engine service life, and the engine replacement in the frontline fighter units was an almost daily practice.

On the way back home, the plane could take up to 9 wounded on stretchers, or even up to 16 in a seated position (the cabin had exactly 16 seats inside). However, there was never any attempt to use the Shche-2 as an assault transport plane - the lifting of paratroopers (up to 9) concerned the drop of individual saboteurs behind the enemy lines or was of a training nature in non-combat conditions.

The Shche-2 successor was the legendary An-2, a slightly smaller plane with four times more power. Also much heavier, so it cannot be called a motor glider anymore. And using a lot more fuel. An empty An-2 weighs 3,450 kg, takes 100 kg of oil and up to 930 kg of gasoline. The payload limit (at the 5,380 kg MTOW from the concrete runway) is 900 kg, i.e. 2 pilots (with parachutes) and 10 passengers or 8 assault paras with personal weapons. Of course, the fuel tanks do not have to be full, but even 30%-filled, they leave a load and crew weight of 1,550 kg (1,420 kg for an unpaved runway), which would mean even 13-15 paratroopers. But the cramped An-2 cargo hold cannot accommodate that much, being more than 7 ft shorter than in Shche-2 and equipped with 12 seats.

Of course, thanks to the quadruple power, the biplane An-2 exceeds 150 mph and reaches the 14,000 ft altitude in 25 minutes (climb is 600 ft/min). But - thanks to the automatic slats, full-span flaps and flaperons, and 800 sq ft wing area - the stall speed is the same 40 mph. However, the take-off performance is better thanks to the lower power loading of 12 lb/hp - 700 ft is enough for the run and 1,600 ft to clear the 50 ft obstacle. On the other hand the landing characteristics suffer from a greater wing loading of 16 lb/sq ft - landing run is  700 ft and 1,400 ft for the 50 ft obstacle descent.

Oops - I can see that I wrote a bit too much - sorry

Cheers

Michael

 

[TheyJammedKenny!]

It's fine.  Thanks for the insights!  Whatever its drawbacks, the Shche-2 may have been a useful introduction to multi-engine aircraft for new pilots.  How did Polish pilots transition to the C-47 and IL-14?

[JWM]

50 minutes ago, KRK4m said:

the lifting of paratroopers (up to 9)

I based on raw technical data, however indeed on three photos with paratroops gathering nearby Shche-2 there are always nine of them.

Regarding advanced pilot training in Poland for multiengined airplanes at the end of WW2 and soon after. There were six Tupelev/Archangielskij USB

http://www.samolotypolskie.pl/uploads/Products/product_341/preview_Archangielski_USB.jpg

 

soon after war replaced by few Suchoj UTB

http://www.samolotypolskie.pl/uploads/Products/product_2792/UTB-2_plany.jpg

 

and Pe-2 UT.

But they were all trainer for bombers rather then transport machines. 

Regards

J-W

 

[KRK4m]

14 hours ago, TheyJammedKenny! said:

How did Polish pilots transition to the C-47 and IL-14?

 

Are you asking about civil or military aviation? In the air force - as my brother @JWM wrote - there were trainer versions of the bombers: USB, UPe-2, UTB and Uil-28. In turn, each twin-engined transport (C-47/Li-2, Il-12/14) always has a double control system. The training is simple: the instructor sits on one seat, and the student next to him.

But Polish civil aviation after WW2 is not only the C-47 and Il-14. Although in Poland in 1929-90 there was only one airline - the state-owned Lot. But in 1945-60, its fleet consisted of 14 C-47, 39 similar Li-2, 5 French SE-161 "fours", 5 Il-12, 13 Il-14 and 5 CV-240.

It is worth mentioning that before the war, Lot operated DC-2, Ju-52/3m and Lockheed L-14 planes (these served the 2500 miles route Helsinki - Warsaw - Athens - Tel Aviv). Using the L-14, in 1940 it was planned to launch a 9-stage connection from Warsaw via Casablanca, Dakar, Natal, Rio de Janeiro, Buenos Aires, Lima, Panama, Mexico to LA. In May 1938, the Lot flight crew carried one L-14 from the USA to Poland along this route eastbound, covering 15,000 miles in 85 h flying time.

During WW2, Lot pilots (as part of RAF Atfero) flew thousands of planes across the Atlantic from the USA to Europe and Africa. Many of them returned to Poland and (if they had not served in RAF combat units) they were restored to work. The crew members of the RAF bombers had a worse situation - they were accused of contacts with enemy intelligence and only in 1956 they were allowed to work in Lot . These people did not need to be trained - they were the elite among pilots.

Next generation of the Lot pilots were military pilots who have retired after 15 or 20 years of service. In the 1960s they had years of flights on the Pe-2, Tu-2, Il-28, but also on the C-47/Li-2 and Il-12/14. A separate group were pilots with no military experience, with only sports aviation in flying clubs behind them. Their training for multi-engine machines was carried out by the light twins (14 Cessna UC-78, 6 French SNCAC NC-701 and 3 Czech Aero 45) purchased by Lot in 1946-52.

Cheers

Michael

Edited April 14, 2021 by KRK4m