'Putilov STAL-3bis' to Verify

Thank you Flyer!:rolleyes:

OK, I drop the “bis” and store this aircraft as “Putilov STAL-3 with M-17 engine”. Your other details will be kept in the picture’s comment section.

Best regards, RT

Dear RT !

To answer Your questions:

1) Yes, in early Russian designations the “bis” means “modified” (like Italian aircraft designations of that era). But Russian Aviation historians do not confirm the existence of “Stal -3bis” designation for M-17-engined “Stal-3” aircrafts. This is possibly, such “designation” was used in some unofficial papers or in conversations to distinguish one type from another.

2) Russian abbreviation “OOS” means “Department of Experimental Aircraft Construction”, which was established in beginning of year 1930. The Chief Designer of this department was A. I. Putilov; there also other designers worked in OOS.

So, we can write full aircraft name: OOS “Stal-3”, or Putilov “Stal-3” – both ways are right.

bis means modified.

Hi friends,

thank you for your answers!:)

But I still need some details:

1) Can you verify the suffix “bis” for this aircraft?

2) “Putilov” is the same like the armament factory, later named “Kirov”? In this context, the brand name “OOS” has nothing to do with either?

Thank you for interest + further answers!;)

Regards, RT

Hello from Russia, dear RT !

Mr Al Elliott was faster with his answer !

Yes, this is very rare photo.
Here is “Stal-3” airplane, equipped with water-cooled M-17 engine.
Fuselage windows exists, of course – You can not see them because of angle of shot.
Some examples of usual “Stal-3” airplanes with radial engines were later re-equipped with M-17 engines. But this replacement has not brought any advantages in comparison with radial motors.

According to “The Osprey Encyclopedia of Russian Aircraft 1875 – 1995” (by Bill Gunston), p278, ‘several’ Stal-3 were equipped with the M-17 engine, a license product of the BMW VI water cooled V-12-engine.

Al