1/72 - Kamov A-7 BIS and A-7-3A Soviet autogyros by Amodel - released

[Homebee]

Amodel is to release 1/72nd Kamov A-7 BIS and A-7-3A Soviet autogyro kits - ref.72257 & 72289

Source: http://hobbyterra.com/product/a-7bis-soviet-autogyro-amodel-72257.html

Source: http://hobbyterra.com/product/a-7-3a-soviet-autogiro-amodel-72289.html

V.P.

Edited October 3, 2014 by Homebee

[Homebee]

Released

http://hobbyterra.com/product/a-7bis-soviet-autogyro-amodel-72257.html

V.P.

[Homebee]

German in-box review ZAGI A-7-3A - ref.72289

http://www.ipmsdeutschland.de/FirstLook/Amodel/Amodel_ZAGI_A-7-3A/Amodel_ZAGI_A-7-3A.html

V.P.

[Antoine]

I'm wondering what's the point to have those large wings together with the rotor?

Something to do with the ability to carry heavy loads?

[Ex-FAAWAFU]

At a guess, to enable it to carry more weapons and unload the rotor at higher speeds, (it's an auto gyro, not a helicopter, remember)

[Antoine]

Is it not what I'm saying?

Most autogyros that I've came upon did not have any wings at all.

[Aardvark]

On 7/3/2015 at 4:40 PM, Antoine said:

Most autogyros that I've came upon did not have any wings at all.

Most autogyros was were much more small than A-7.

That's fresh article, with factory drawings (!), direct response why A-7 was with its wings there is no, but there are many other interesting information:

https://warspot.ru/13589-letayuschie-glaza-artillerii

As, examples, unknown data about A-7, experimental binocular-glass :

windows under fuselage (anybody's see 

their in A-model?):

Interesting facts from article about A-7:

- the competitor A-7 was a Soviet copy of Fi-156 Storch - OKA-38 "Aist" designed by O.K.Antonov.

A-7 exceeded the OKA-38 only in maximum speed, no other advantages were mentioned;

- despite the fact that most of the A-7s built were in accidents, they could be quickly repaired and re-run;

- many of the military simply did not know what to do with the A-7, the tactics of its use in the war was incomprehensible;

- A-7 group of designers led by N.I.Kamov

(One of the deputies was M.L. Mil)was going to be put on trial, but the intercession of A.S. Yakovlev, who managed to convince everyone that A-7 just ahead of his time, saved them.

 

....Imagine if Kamov and Mil were convicted by the court and imprisoned, perhaps now there would be neither Mi-8 / Mi-24 / Mi-26, nor Ka-27 / Ka-50/52 e.t.c. .... but then it is possible, in this alternative universe, Soviet helicopter would develop Yakovlev and Bratukhin ....

 

 

B.R.

Serge

_________________

*-"behind tomorrow"

😁?

[Aeronut]

Cierva’s earlier autogyro designs did have wings and tail planes with control surfaces as his rotor only provided lift. He soon realised that by directly controlling the rotor he could dispense with the main planes and ailerons and the tail surfaces could be used solely for balance and trim. Raoul Hafner showed in 1936 with his first autogyro design (the AR III) that by using a rotor that had both cyclic and collective control even the tail could be reduced to just a fin and rudder for balance. The AR III was also the first rotorcraft (not just autogyro) to fly successfully with this type of control over the main rotor, a configuration that became standard in helicopters.

[Aardvark]

@Aeronut, I am not an expert in the autogyro area, but as I understood from the article, A-7 at the time of its creation was the most heaviest and largest armed autogyro.

Besides the fact that the A-7 weighed about 2 tons, that is, two times more than most of the western autogyro

, the A-7 also had a higher proportion of metal in the structure while the other autogyro

were mostly covered with cloth.

Therefore, it is likely that the wing would unload the rotor.

As indicated in the article, the only Western autogyro

Pitcairn PA-36

http://www.airwar.ru/enc/law1/pa36.html

and Pitcairn PA-38

https://sites.google.com/site/stingrayslistofrotorcraft/pitcairn-pa38-attack-autogyro/Pitcairn PA.38 attack autogyro.jpg?attredirects=0

was close to the A-7 on weight and dimensions. 

 

But the first was not armed, and the second was not even built! Although the experience of operating the A-7 USSR wanted to buy.

Before that, the USSR bought the Sierva S-30 and carefully studied it:

Here is what Mikhail Maslov writes about this:

"According to Izakson’s handwritten notes (conversation with M. S. Arlazorov on 01.02.71), in one of the flights at a low altitude, the 

autogyro

unexpectedly turned over and carried out the barrel. At the time of execution of an unplanned figure, the autogyro

lost height and hit the ground. In the cockpit were two pilots who remained alive, the autogyro

was significantly damaged.

After the repair, the flights continued and ended with another similar incident. When carrying out a planned flight of the C-30 at a height of 30 m turned over on his back. Pilot Ivanovsky was not wearing seat belts, so he fell out of the cockpit. Fortunately, he safely passed* the rotor blades and fell into a deep snowdrift on the edge of the airfield. The autogyro was smashed.

.........

Incidents with the S-30 led to the emergence of another research work M. L. Mil. According to his conclusions, they occurred because of the insufficient stability of the 

autogyro  and under the combination of adverse conditions, when there was a strong side slip and the pilot did not parry the lateral roll in time."

Resource:

https://military.wikireading.ru/8024

Therefore, it is likely that the wings on the A-7 not only unloaded the carrying propeller  but also solved the problem of stability!?

 

But this is just my guess.

 

The early work in the USSR on an autogyro and a helicopter still contain many white spots and riddles, so the article on the A-7 is very interesting. But the author of this article is a very serious tank expert working in archives, so A-7 is not his main focus.

 

I will see what is written about the wing of the A-7 at Isakson and Shavrov .... but if there is nothing there about the reasons for the appearance of the wing, then we can only guess.

 

_____________

* - Oh, lucky!!!!!

 

B.R.

Serge