ANT-63, '63' SDB by A.N.Tupolev/ STO-3/ OTB

The first variant of SDB (rebuilt '103'),
"History of aircraft construction in the USSR", Vol.2 p.172

There were two different SDB aircraft of Tu-2 family. Both were built in 1944, during 'quest' for daytime high speed bombers.

First one was old good '103' re-engined with AM-39 engines. It was converted into two-seater - pilot and navigator. All machineguns (nose-mounted and defensive) deleted.

First flown by A.D.Perelet on May 21, 1944. Speed and climb characteristics were excellent, but VVS did not accept absence of defensive armament.

The second variant of SDB (based on series Tu-2S),
"History of aircraft construction in the USSR", Vol.2 p.172

Other variant with AM-39F engines was based on series Tu-2S. Central wing section was modified, landing gear was converted into single-strut instead of the 'fork'-type used on other Tu-2. Crew was increased to three (gunner is back), armored seats returned as well as two UBT defensive machineguns.

Aircraft was ready on October 14, 1944. Joint trials (Factory and State Acceptance) continued well after Germany capitulation and ended on June 30, 1945. Despite increased weight (by 800kg compared to the first SDB) and slightly degraded performance, aircraft was well suited for production. The only suggestion was to improve navigator's sight.

SDB was and intermediate variant, and was put aside because more radical and promising Tu-10 was already undergoing trials.

Predecessors		Modifications
'103' '58' ANT-58	'61' ANT-61 Tu-2S	None

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References	Links
"History of aircraft construction in the USSR", Vol.1 p.172-173;	...