20k b/w ANT-4 prototype with mockup torpedo, "History of
aircraft construction in the USSR" by V.B.Shavrov, Vol.1 p.371
The first in the World
all-metal cantilever twin-engine bomber. Layout of the ANT-4 was reproduced
all over the World since 1930, after the first international appearance.
All following multi-engine bombers added no radical layout changes to this
aircraft of 1925, exept airdynamic and structural refinement, number of
engines and guns, different levels of equipment sophystication.
It is interesting that this (mostly) land-based aircraft has a naval
pre-history. In 1923-1929 the Special Technical of military inventions
(Ostekhburo at Leningrad, headed by V.I.Bekauri) badly needed a heavy bomber
aircraft for their research (naval torpedos). Plans to buy some in the
Great Britain did not materialize. As a result, A.N.Tupolev at the TsAGI
started to work on this project (November 11, 1924). Timeline was only
9 months. Aircraft was assembled on the second floor in non-industrial
building! In addition to this A.N.Tupolev had not enough skilled workers.
Despite all odds, ANT-4 was ready in time. It was 'extracted' from
the second floor, through removed building wall on August 11, 1925. In
October 1925 assembly was finished on the Moscow Central Airfield. On 26
November, 1925 first flight was performed by pilot A.I.Tomashevskij. It
took 7min to carry out preliminary evaluation.
Following the flight, some changes were introduced into design. Next
flight (35min, 15 February, 1926) was a complete success, and on
March 26 ANT-4 fulfilled factory trials. Special representatives from Ostekhburo,
TsAGI and NOA were present. Pilots A.I.Tomashevskij and N.N.Morozov suggested
some minor modifications, and on June 11 State Acceptance Trials started.
On July 2 unanimous conclusion: 'First Class Aircraft' lited green light
to production of ANT-4/TB-1.
But it took some time before series manufacturing started. Prototype
had single set of controls, carried no defensive veapons, no radio, no
navigation (and photo) equipment. Original Lorraine-Dietrich engines were
replaced by BMW-VI. Following replacement by license built copy M-17
|None. First aircraft of the class in the World.