Soviet Composite Bomber Projects: The Early Tsybin
By Raul Colon
October 4th 2008
Paver Vladimirovich Tsybin . Born 23 December 1905. Died 4 February 1992.
The idea of combining two aircraft, a mother-ship and a deployable
secondary plane; has been around since the late 1920s. In fact, it was a
Russian who developed the world’s first true operational composite
project, the Vakhmistrov Zveno bomber. As promising as it was strange, the
Zveno concept did perform several successful operations proving the
Vakhmistrov Zveno bomber
The Russians halted further in-depth research into the concept by the end
of WW II until the early years of the 1950s when the advent of the
powerful United States’ Air Force B-58 Hustler Bomber gave rise to the
Soviet Union’s first true modern composite programmes. The idea behind the
new Soviet concept was simple enough. A heavy lifting strike airplane
would carry a fully loaded bomber to a point within its operational range.
The bomber would then be deployed and proceed to its assigned target area
by its own power. By the early part of the 1950s, all of the Soviet
Union’s Experimental Design Bureaux (OKB) were well entrenched among the
USSR’s state-run aircraft industry. They were extremely well funded, by
Soviet standards, and well connected politically. This was probably one of
the better examples of the USSR’s industrial monopoly. The OKB’s divided
the design and development aspects among each other, thus preventing a new
member to move in on what they believed was their territory.
Two OKBs were able to break the Experimentals’ hold on design and
development. One was the famous Myasishchev Bureau. The other, more
obscure one, was the OKB headed by Pavel Tsybin. Tsybin was a major glider
designer as well as designer and pilot of several rocket-propelled
research aircraft. Since the early 1950s, Tsybin had worked on nuclear
weapons delivery platforms which were to be deployed from a larger,
“mother-ship”-type of aircraft. Later his research in this unusual field
earned him his own Bureau, OKB Number 256. No small feat on such tense
His OKB’s independence, however, was short lived and in October 1959, the
Myasishchev Bureau absorbed Tsybin’s small venture. Before Tsybin’s
beloved 256 was registered, let alone acquired by the powerful Myasishchev
OKB, he was in charge of the development of a supersonic heavy bomber
capable of deploying the new thermonuclear weapons just arriving at
On March 4th 1954, Pavel sent his design for such a platform to top
aerospace officials inside the Kremlin. His design for called for a
Reaktivnyi Samolyot or RS platform. One that could be capable of achieving
speeds up to 1865 mph with an operational range of 8701 nautical miles.
Top ceiling was assessed at 98425’. It would had an operational maximum
takeoff weight of 36376 pounds. In order to achieve this impressive
profile, the RS design called for extremely thin wing structures fitted
with two powerful engines on each wing tip. To reach the necessary
thrust-to-weight ratio for the called profile, Tsybin’s design team
streamlined the fuselage. They also added two forward canard fore planes.
The new aircraft design would be able to deploy the new Soviet winged bomb
based on the 244-N thermonuclear weapon. The top brass at the Kremlin took
Tsybin’s proposal very seriously despite warnings from various quarters,
mainly others OKBs, that the available technology to develop such an
aircraft was not yet sufficiently tested. Nevertheless, work proceeded on
the RS design and on May 5th 1955, Tsybin’s team presented the concept to
leaders of the Communist Party. Tsybin’s presentation was a resounding
success and on May 23rd, a Soviet Ministry (SovMin) resolution allowed the
overachiever Tsybin to establish his own Bureau. The resolution also asked
for a flying prototype to be delivered no later than February 1st 1957
followed by another unit by April 15th.
The establishment of an independently-run Bureau was a complex task.
Hiring of a highly trained staff was a top priority, but with fierce
competition among the other Bureaus, the new OKB 256 were unable to grab
the “lion's share” of the managers, designers, engineers, mechanics and
other skilled workers needed for such a radical project. Beside those
immense problems, Tsybin was also faced with a powerful dateline.
Notwithstanding, he and his small team pushed ahead and by the winter of
1955, the OKB’s design team modified the original RS’s profile.
Operational range was now established at 4661 miles. Also, work on a newly
designed RD-013 ram jet engine had commenced in earnest.
With the change of range profile came the idea of joining or “pegging” the
new platform to a Tupolev’s Tu-95. It was determined that a Tu-95 could
“carry” the RS up to 2485 miles before deploying the platform for its own
flight. By January 1956, the RS programme had developed its first mock-up,
vaguely similar to the British Avro 730 supersonic bomber. The new RS
incarnation had a long and narrow airframe with a small trapezoidal wing
structure supporting one engine on each wing tip. The team reformed the
two canards foreplanes, now each would measure 10’-2” instead of the
original 12’-0”. Plans called for the RS to be loaded into the belly of a
Tu-95-N (N) for the carrier version of the aircraft. Once the Tu-95
reached the pre-arranged altitude of 29530’, it would deploy the RS which
would then proceed to its assigned target at speeds of up to 1865 mph. On
its first solo stage, the RS would be powered by two assisting rocket
engines which would be jettisoned soon after they spent themselves. Then,
the two wing tip ram engines would ignite powering the craft to its
destination. The engines, capable of powering the RS at speeds near Mach
2.8, were configured on a fixed geometry, multi shock inlets with
convergent divergent nozzles. The RS’ fuel tanks were able to carry 23083
lb of aviation fuel. The bomber’s nuclear weapon, weighed in at 2425 lb,
would had been carried on a tailless delta platform fitted on the rear end
of the fuselage.
As promising as the RS project seemed, it was destined to fail. At the
same time Tsybin and his team was developing the outlines and designs of
the RS, the Korolyov OKB was hard at work on an Intercontinental Ballistic
Missile (ICBM) system code-named R7. In early 1957, the new ICBM made its
maiden flight and later that year, it achieved production status. The
development of the R7 was a sever blow to the RS concept. Immediately
after the successful test flight of the R7, all work related to the RS was
Although work on the RS was cancelled, Tsybin still managed to work of an
offspring project called 2RS Reconnaissance Aircraft. The 2RS concept was
first conceived in January 1956 and was also designed to use the Tu-95N as
its springboard plane. But, unlike the RS, the 2RS was not designed as a
nuclear delivery bomber, thus the designers replaced the canard foreplanes
with a slab tailplane configuration. The fuselage specifications, beside
the replacement of the canards structures, were the same of the original
concept. The only difference was a reduction in frame length to 89’-11”.
Maximum takeoff weight (loaded with camera systems) was now 46186 lb. The
2RS would had been able, accordingly to its specs, to reach a top speed of
Mach 2.54. Ceiling was estimated at 88583’ with an operational range of
4351 miles. But by the time the 2RS was ready for mock-up design, passion
for this particular reconnaissance platform has dramatically declined
among Kremlin leaders.
From August 1956 onward, OKB 256 shifted its design effort from the 2RS to
the newly constituted RSR aircraft. The RSR project, which called for an
all jet, instead of ram engine configuration, was born on August 31st
1956. Most of the preliminary work on the concept was completed by June of
the following year. The new platform was designed to takeoff and land on
its own power. To accomplish this new task, the RSR was fitted with a
reinforced bicycle undercarriage with a double wheeled main and nose
gears. Powering the RSR were two Solovyov Low Ratio D-21 Turbofan engines.
The new concept airframe, instead of being developed from titanium and
steel alloys, was made out of lighter materials. This was due to the
anticipated reduction in stress being applied to the fuselage by the
turbofan engines. The aircraft’s profile called for outside temperatures
of around 200 degrees C.
The new project was one of the first Soviet aircraft fitted with a
rudimentary feature of stealth. The advent of ever more powerful
Surface-to-Air Missiles (SAM) forced this seldom mentioned development.
The RSR’s lower fuselage section and wing structure were coated with a
porous material designed to absorb the electronic energy emanating from an
enemy’s radar arrays. Beside the coating, the plane’ fuselage was
re-stressed to allow the pilot to make a barrel role to an altitude of
137795’ or to perform a climb and turn at the same time with a rapid
change in altitude. Both manoeuvres were designed to exceed the estimated
2.5G force needed to escape an incoming Western-built SAM.
Two massive storage tanks were able to carried up to 26455 lb of fuel. Two
additional external fuel tanks, housed underneath the wing structure, were
capable of supplying another 4850 lb of fuel thus extending the aircraft’s
range. The RSR proposed range was now a more realistic 2339 miles radius.
Accordingly to the SovMin resolution of 1957, the first RSR prototype
would be rolled out of the production line no later than the spring of
1958. As the same time Tsybin’s team was working on the RSR project,
another concept, the 3RS began to take shape. The 3RS was intended to be a
dual use platform. It would be able to takeoff on its own or it could be
deployed the same way the RS and 2RS were designed to do. The whole idea
behind the 3RS was range. Soviet military leaders were still searching for
the ultimate bomber. One capable of reaching America from Soviet held land
bases. Another step towards the realization of Tsybin’s dream came true
when on March 20th 1958, the SovMin authorized full development of the
Tu-95N platform. The Tupolev Bureau was not pleased with the resolution.
Andrei Tupolev himself thought that the whole concept as a complete waste
of, not only valuable technical resources, but more importantly; time.
Utilizing his enormous influence, Tupolev was able to shift the
development of the ‘mother-ship” or main aircraft to the Myasishchev
Bureau freeing himself to develop more heavy bomber concepts.
Meanwhile, Tsybin team was laying the ground work for the creation of a
scale model known as (Naturnaya Model). On November 1956, the
Kremlin made available the necessary funds available for the whole
programme. Another major accomplishment for such small enterprise. The
experimental NM-1 was fitted with two Mikulin AM5 engines mounted on
simple nacelles, which meant that the aircraft could only achieve subsonic
speeds due to the nacelles’ low power rating. A retractable skid
arrangement was placed under the engines’ nacelles. For takeoff
operations, a two-wheeled trolley was installed under the skids. This
mechanism would be jettison once the aircraft was aloft. A small tail
wheel was also installed for taxing control. Beside a shorter nose cone
section, the NM-1 fuselage and materials were almost identical to that of
the original RSR concept. On April 7th 1959, after several aborted
attempts, the NM-1 took to the air for the first time.
Overall, 32 test flights took place between the spring of 1959 and autumn
1960. Results from the tests were disappointing at best. Data collected
demonstrated that the aircraft was not able to maintain a regular flight
pattern. Plus, its takeoff profiles made it easy to roll over. Those
deficiencies meant that the developmental phase of the concept needed to
be pushed farther than the OKB wanted. Not the news Tsybin was looking
for. He understood that delaying the rollout of the first true prototype
could very well lead to the termination of its beloved OKB. He was
determined not to have his OKB terminated. Tsybin feverously lobbied the
Soviet Politburo and the VVS Command for extensions. Both institutions saw
the creation of such a radical platform a necessity paving the way for
Tsybin was get his extension on the aircraft’s delivery date. The new
dateline was now pushed to December 1960.
With his extension on hand, Tsybin re-doubled his efforts on the RSR
concept. He redesigned some of the aircraft’s features and tested its
profiles on several mock-ups. Everything seemed to be ready for
development, everything except the D-21 engines. The Tupolev Bureau
pressured the Factory 19, the main manufacture centre for aircraft engines
in the USSR, to built more of the D-20 engines for its popular Tu-124
airliner jet, thus placing strains in the Factory’s ability to deliver new
and revolutionary engine systems on time.
Tsybin did not receive a single D-21 from the Factory. He replaced the
highly anticipated D-21 with two Tumansky R-11F jet engines with reheat
capability. Unfortunately for Tsybin, the new engine required further
fuselage modifications. To accommodate the new engines, he and his team
slimmed and enlarged the engines’ nacelles. They also installed a central
shock cone on each intake similar to that used on the much vaunted
Mig-21F. The new engines also gave the plane a change of code names to RSR
R-020. Engineers began to strip down the new RSR version in an effort to
reduce its weight. The volume of internal ribbing in the wing structure
was increased. Thinner areas were applied throughout and welding replaced
many of the fuselage’s riveted joints. The titanium and steels alloys were
replaced by Dural as the airframe primary structural material.
All these modifications had the effect of reducing significantly the
fuselage’s fatigue life to just about 200 flying hours or three to six
flights. The resulting airframe was one extremely light compare to other
similar structures. New external self-sealing fuel tanks, capable of
storing 2866 lb of fuel, were added to the plane. Total fuel load capacity
was now 10700 lb. The wings were also re-jigged. More taper was applied to
their trailing edges and tailplane sections. Also the fin area was
reduced. The RSR-020 sported a new undercarriage arrangement. Gone were
the two large wheels, replaced by four smaller sets. The modified version
would had a serviceable ceiling of 73819’ with an operational range of
Five RSR R-020 units were ordered in early 1959, but again, the
development of the ICBM as a formidable weapon platform trumped Tsybin’s
dream aircraft and on October 1st, Soviet Premier Nikita Khrushchev
ordered the termination of OKB 256. The cancellation of Tsybin’s OKB
contract did not meant that the RSR programme was dead. Design and
development of the RSR aircraft passed on to the Myasishchev OKB. At the
time of the transfer, Myasishchev was immersed in its own bomber concept
which gave Tsybin almost a free hand in developing the RSR concept.
Development of the RSR was relocated to the Myasishchev OKB’s Zhukovsky
facility on September 29th 1960.
Work was again halted the next month. On October 1960, Vladimir
Myasishchev was appointed head of the Tsentrahl’nyy Aero-I
Ghdrodinameecheskiy Institoot (TsAGI) or Central State Aerodynamic and
Hydrodynamic Institute. For a brief time, the Chelomey OKB took control of
the project, but it was short lived. By now, most of the Soviet’s OKBs
were either performing work on ballistic missile systems or on the
country’s nascent space program. As the new head of the powerful TsAGI,
Myasishchev officially ended all work related to the RSR platform. He
transferred Tsybin and most of his original engineering team to his OKB’s
space division which at the time was developing the Soyuz space capsule.
With his transfer and the cancellation of all RS-programs, all of the
RS-related data was sealed or destroyed.
Today what remains of the original RSR concept are but a few documents and
drawings which clearly indicated that the aircraft was in its initial
construction stage when the program was axed. Some documents suggested
that up to three units were completed but there’s no evidence to support
this claim. What is well documented was that soon after the RSR program
was cancelled, Myasishchev wrote a letter to Tsybin that contained a TsAGI
drawing for a supersonic reconnaissance platform very similar, if not
almost identically, to the RSR. A fact that did not sit well with Pavel
Tsybin or his team. For years, Tsybin suspected that Myasishchev had a
hand in the cancellation of, not only his RS platform, but his beloved OKB.
With the termination of the RSR and the British Avro 730 programs, only
the United States developed a RSR-type platform that actually flew. It was
the spectacular Lockheed SR-71 Blackbird.
Soviet X-Planes, Yefim Gordon and Bill Gunston, Midland Publishing 2000
Aircraft of the OKB Tupolev, Vladimir Rigmant, Moscow Russavia 2001
Russian X-Planes, Alan Dawes, Key Publishing 2001
Concept Aircraft: Prototypes, X-Planes and Experimental Aircrafts, Editor
Jim Winchester , Thunder Bay Press 2005