USB evolution and painting
Updated on 23 November 2011
back to VVS research index
back to I-15 index

Disclaimer: this work collects a lot of photos and drawings from many sources, not always identified and mentioned.
If someone has rights on the images reproduced here, please don't feel hurted, email to me and I shall provide to remove or to credit them.

USB

When the SB became fully operational, a training version with double commands was needed.

In 1938, Factory n.22 developed a new nose section with an opened cockpit for a flight instructor. This nose section could have been quickly fitted on existing airframes. In 1938, it produced 29 new USB and 81 conversion sets to be sent to units.

Unsatisfied with the durability and smoothness of AE-9 grey enamel on the anodized duraluminium surface, the technicians of Factory n.22 started to paint the SB with aluminium enamel AE-8 for a period of 6-12 months during 1938 (and perhaps the end of 1937). Later, they reverted to AE-9 light grey.

The aluminium finish was employed only on some SB 2M-100A and early M-103, and contemporarily built USB.

AE-9: gloss light grey oil enamel introduced in 1937. It became the main standard color of SB.
AE-8 aluminium: oil enamel utilized to paint SB during some months in 1938. Later they reverted to AE-9.

 

The USB prototype at state tests in March 1938. It was fitted with an unretractable ski gear and, probably, M-100A engines. The variable-pitch propeller without spinner and starter cog.

Nationality marks are visible in standard positions.

The plane looks painted overall grey AE-9, apart for Venturi tubes that were usually painted black.

from Tupolev SB of M. Maslov, Icarus aviation press

The instructor's cockpit was open and provided with a windshield only.

from Tupolev SB of M. Maslov, Icarus aviation press

Details of the front of the canopy and of its left side.

from Tupolev SB of M. Maslov, Icarus aviation press

USB in light grey finish, with an additional red star with white outline painted on its nose.

Two images of USB 2M-100A in winter 1939/40. The plane looks in silver finish, with unretractable ski gear and bays closed by fixed covers. Note the access to the instructor's cockpit.

Both engines and propellers are protected by adhering covers. The armament of the rear positions appear not installed.

From Tupolev SB of M. Maslov, Icarus aviation press

 

 

USB 2M103A captured by Germans during operation Barbarossa in summer 1941. It wears a light grey livery, but the nose appears from a green plane. Note the VM-3 ball-like turret, probably a refitting.

An elegant black '4' is visible on its rudder.

An USB M-103A shot down by Finns during the Winter War.

On the rudder, a light (yellow?) 11 outlined in black can be seen, on which a red 3 is overposed.

 

These three images depict the same plane. It is equipped with sharp M-103 A or U engines, and features the 'tall' pilot's windshield often seen on earlier flat-engined SB 2M-103and the landing light on the left wing leading edge.

The building of the airframe is datable to late 1939 because of the movable shutters at the cooler's intakes, so it was originally painted in uniform AE-9 light grey as of use on that period; the uppersurfaces were painted in A-19f alkyd green after the summer of 1940 when the painting standard changed.

The installation of the shiny nose, painted in silver, was clearly made after this repainting.

The spinners seem to be painted in grey (or white) and red; a red (?) 1 seems painted on the rudder on all photo.

Reversely, here we see a SB with tall windscreen on which a nose from a green/grey or green/blue plane was mounted. Or maybe have someone exchanged the nose with the one of the previous image?

Image courtesy Jan Konnig

USB 2M-100 or 103 of the 72th SAP of the Northern Fleet, autumn/winter 1941. It features green wavy lines on light grey background, a white rudder tip, a small red (?) 6 on its rudder and probably prewar-style disposition of the red stars.

from Aviamaster 2001/05

On 20 June 1941, the last day of peace, it was published an order of NKAP (the Ministry for Aeronautical Industry) to paint all planes with a new standard camouflage within one month.

For newly built planes, the instructions said to utilize matt light blue for undersurfaces (not specified what type of paint, but all previous light blue paintings were gloss, so they have to be A-28m for all-metal planes and AMT-7 for mixed construction planes).

Apart for some Yaks, the first known photos of planes with the new green/black painting scheme are dated to July 13, 1941.

Many maintenance manuals of the first years of war describe these paints: dope AMT-4 green, AMT-6 black and AMT-7 blue enamel or oil A-24m, A-26m and A-28m of the same colours. Oil colors were less utilized, also because AMT colors can adhere well to primed metal surfaces.

Despite their name (M= matt), AMT colors were semigloss when new, and turned to matt finish with ageing. Occasionally, they could have been overpainted with a layer of gloss varnish AB-4-d to improve aerodynamicity and gain some speed.

While AMT-4 and 6 were codified in July 1941, AMT-7 was codified in August 1941, and is not mentioned on earlier manuals; earlier AII light blue remained in use in parallel with the darker AMT-7 in the first years of war.

Oil enamels were intended to be sprayed on the exterior metal surfaces, even unprimed. Painting with a brush meant poor paint properties, and was allowed only as a second choice, ex. for repairs.

Prop blades were now fully painted black.

The order of June 1941 changed the national marks of planes too. Red stars, of plan type or with thin black outline, were now placed in four or six positions:

  • one on each side of fuselage (not always),
  • one on each side of rudder/stabilizer,
  • one on the undersurface of each wing (lower wing, in case of biplanes).

Note the deletion of stars over the wings, and the introduction of new ones on the tail.

The release of a clear directive on camouflaging the planes with green and black bands, with light blue undersurfaces, reached the units contemporarily with the war outbreak, when the frontline units had other things to worry about.

The directive previded that the existing planes, already painted with a layer of green on uppersurfaces (both AII green, A-19f or earlier types of protective), had to be painted with black bands, eventually preserving the original green and the original color of undersurfaces.

The red stars on the upper face of wings were usually obliterated with camo colors, and new stars were added on the sides of the tail in addition to those on the fuselage.

A-19f green: the standard gloss green for uppersurfaces between June 1940 and July 1941. Easily preserved as a base color after the war outbreak. It's believed to be dark when new, and to fade quickly to a lighter shade preserving the gloss finish for a relatively long time. A-18f: gloss light blue for undersurfaces between June 1940 and July 1941. Easily preserved as color of the undersurfaces.
AMT-4: the standard matt green for new-built mixed construction planes. Possibly utilized to repaint some SB. AE-9: gloss light grey oil enamel, the common base color of SB till June 1940. Easily preserved as color of the undersurfaces.
A-24M: oil equivalent of AMT-4, utilized for all-metal planes. Possibly utilized to repaint some SB. AE-8 aluminium oil enamel: base color for many planes built in 1938. Possibly preserved as a color for undersurfaces.
AMT-6: the standard matt camouflage black, usable both aside AMT-4 and over A-19f green to camouflage old planes. It was not 100% dark, particularly if utilized in a thin layer or faded. AMT-7 matt light blue: standard for undersurfaces of newly-built planes after June 1941. Possibly utilized to repaint the undersurfaces of some old planes.
AMT-1 matt light brown: occasionally utilized in 1941-43 for non-standard camos, became standard on non-fighter planes after the August 1943. AII gloss light blue: standard color for new-built mixed-construction planes (not for all metal SB, then) between July 1940 and June 1941; also utilized after that date as an alternative to AMT-7. Possibly utilized to repaint the undersurfaces of some old planes.

USB 2M-103A with a device to tug gliders.

The red stars on the fuselage were roughly deleted with green paint, and new plain ones, scarcely visible, were painted on the tail to accomplish the directive of the June 1941. The stars over the wings were certainly obliterated in the same way.

USB utilized as a liaison plane in 1943. It seems to wear a black-green camouflage.

From Aviacia i Kosmonautika 2008/11

Two images of an USB 2M-100 or 103 in the Far East, during the preparation of the war to Japan.

This old plane wears post-1943 red stars with white-red outline, a red 2 outlined in white on its rudder, a small red starlet on its nose, probably a black-green camouflage.

The nose and part of the cowling show discontinuity in colors that suggest the use of pieces from another plane.

Note that some of the soldiers wear helmets of obsolete type.

From Aviapark 2010-2

This USB 2M-103A was utilized for bailing out tests. It appear to wear a very faded black-green camouflage and large 1943-style stars with red-white outline on the fuselage, tail and undersurfaces.

From Tupolev SB of Maslov, ed. Icarus

 

USB 2M-100A (the single round window on the side suggests a plane of 1937-38) with a three-shades camo (possibly AMT-4 green, AMT-6 black, AMT-1 light brown), post-1943 stars with white-red outline. The plane features a black (?) 10 (?) and a red trim tab on its rudder.

From Tupolev SB of Maslov, ed. Icarus