Convair B-36 Peacemaker

much more at https://en.wikipedia.org/wiki/Convair_B-36_Peacemaker

The Convair B-36 "Peacemaker" is a strategic bomber built by Convair and
operated by the United States Air Force (USAF) from 1949 to 1959. The B-36 is
the largest mass-produced piston-engined aircraft ever built. It had the longest
wingspan of any combat aircraft ever built, at 230 ft (70.1 m). The B-36 was the
first bomber capable of delivering any of the nuclear weapons in the U.S.
arsenal from inside its four bomb bays without aircraft modifications. With a
range of 10,000 mi (16,000 km) and a maximum payload of 87,200 lb (39,600 kg),
the B-36 was capable of intercontinental flight without refuelling.

Entering service in 1948, the B-36 was the primary nuclear weapons delivery
vehicle of Strategic Air Command (SAC) until it was replaced by the jet-powered
Boeing B-52 Stratofortress beginning in 1955. All but five examples were
scrapped.

As the Pacific war progressed, the air force increasingly needed a bomber
capable of reaching Japan from its bases in Hawaii, and the development of the
B-36 resumed in earnest. Secretary of War Henry L. Stimson, in discussions with
high-ranking officers of the USAAF, decided to waive normal army procurement
procedures, and on 23 July 1943 – some fifteen months after the Germans'
Amerikabomber proposal's submission made it to their RLM authority; and
ironically, the same day that, in Germany, the RLM had ordered the Heinkel firm
to design a six-engined version of their own, BMW 801E-powered Amerikabomber
design proposal – the USAAF submitted a "letter of intent" to Convair, ordering
an initial production run of 100 B-36s before the completion and testing of the
two prototypes. The first delivery was due in August 1945, and the last in
October 1946, but Consolidated (by this time renamed Convair after its 1943
merger with Vultee Aircraft) delayed delivery. The aircraft was unveiled on 20
August 1945 (three months after V-E Day), and flew for the first time on 8
August 1946.

After the establishment of an independent United States Air Force in 1947, the
beginning in earnest of the Cold War with the 1948 Berlin Airlift, and the 1949
atmospheric test of the first Soviet atomic bomb, American military planners
sought bombers capable of delivering the very large and heavy first-generation
atomic bombs.

The B-36 was the only American aircraft with the range and payload to carry such
bombs from airfields on American soil to targets in the USSR. The modification
to allow the use of larger atomic weapons on the B-36 was called the "Grand Slam
Installation".

The B-36 was arguably obsolete from the outset, being piston-powered, coupled
with the widespread introduction of first generation jet fighters in potential
enemy air forces. But its jet rival, the Boeing B-47 Stratojet, which did not
become fully operational until 1953, lacked the range to attack the Soviet
homeland from North America without aerial refueling and could not carry the
huge first-generation Mark 16 hydrogen bomb.

The other American piston bombers of the day, the B-29 and B-50, were also too
limited in range to be part of America's developing nuclear arsenal.
Intercontinental ballistic missiles (ICBMs) did not become sufficiently reliable
until the early 1960s. Until the Boeing B-52 Stratofortress became operational
in 1955, the B-36, as the only truly intercontinental bomber, continued to be
the primary nuclear weapons delivery vehicle of the Strategic Air Command (SAC).

Convair touted the B-36 as the "aluminum overcast", a so-called "long rifle"
giving SAC truly global reach. During General Curtis LeMay's tenure as head of
SAC (1949–57), the B-36, through intense crew training and development, formed
the heart of the Strategic Air Command. Its maximum payload was more than four
times that of the B-29, and exceeded that of the B-52.

The B-36 was slow and could not refuel in midair, but could fly missions to
targets 3,400 miles (5,500 km) away and stay aloft as long as 40 hours.
Moreover, the B-36 was believed to have "an ace up its sleeve": a phenomenal
cruising altitude for a piston-driven aircraft, made possible by its huge wing
area and six 28-cylinder engines, putting it out of range of most of the
interceptors of the day, as well as ground-based anti aircraft guns.


Role
Strategic bomber

National origin
United States

Manufacturer
Convair

First flight
8 August 1946

Introduction
1948

Retired
12 February 1959

Primary user
United States Air Force

Produced
1946–1954

Number built
384

Unit cost

US$4.1 million (B-36D)
($33.2 million in 2016 dollars)

Variants
Convair XC-99
Convair NB-36H
Convair X-6

Developed into
Convair YB-60


Engine fires

As engine fires occurred with the B-36's radial engines, some crews humorously
changed the aircraft's slogan from "six turning, four burning" into "two
turning, two burning, two smoking, two joking, and two more unaccounted for."
This problem was exacerbated by the propellers' pusher configuration, which
increased carburetor icing. The design of the R-4360 engine tacitly assumed that
it would be mounted in the conventional tractor configuration—propeller/air
intake/28 cylinders/carburetor—with air flowing in that order. In this
configuration, the carburetor is bathed in warmed air flowing past the engine,
and so is unlikely to ice up. However, the R-4360 engines in the B-36 were
mounted backwards, in the pusher configuration—air intake/carburetor/28
cylinders/propeller. The carburetor was now in front of the engine and so could
not benefit from engine heat, and also made more traditional short term
carburetor heat systems unsuitable. Hence, when intake air was cold and humid,
ice gradually obstructed the carburetor air intake, which in turn gradually
increased the richness of the air/fuel mixture until the unburned fuel in the
exhaust caught fire. Three engine fires of this nature led to the first loss of
an American nuclear weapon when a B-36 crashed in February 1950.

Operating and financial problems

Due to problems that occurred with the B-36 in its early stages of testing,
development and later in service, some critics referred to the aircraft as a
"billion-dollar blunder". In particular, the United States Navy saw it as a
costly bungle, diverting congressional funding and interest from naval aviation
and aircraft carriers in general, and carrier–based nuclear bombers in
particular. In 1947, the Navy attacked congressional funding for the B-36,
alleging it failed to meet Pentagon requirements. The U.S. Navy held to the
preeminence of the aircraft carrier in the Pacific during World War II,
presuming carrier-based aircraft would be decisive in future wars. To this end,
the Navy designed the USS United States (CVA-58), a "supercarrier" capable of
launching huge fleets of tactical aircraft or nuclear bombers. It then pushed to
have funding transferred from the B-36 to the USS United States. The Air Force
successfully defended the B-36 project, and the United States was officially
cancelled by Secretary of Defense Louis A. Johnson in a cost-cutting move.
Several high-level Navy officials questioned the government's decision, alleging
a conflict of interest because Johnson had once served on Convair's board of
directors. The uproar following the cancellation of United States in 1949 was
nicknamed the "Revolt of the Admirals".

The furor, as well as the significant use of aircraft carriers in the Korean
War, resulted in the design and procurement of the subsequent Forrestal class of
supercarriers, which were of comparable size to the United States, but with a
design geared towards greater multirole use with composite air wings of fighter,
attack, reconnaissance, electronic warfare, early warning and anti-submarine
warfare aircraft. At the same time, heavy manned bombers for the Strategic Air
Command were also deemed crucial to national defense and, as a result, the two
systems were never again in competition for the same budgetary resources.

Obsolescence

With the end of fighting in Korea, President Eisenhower, who had taken office in
January 1953, called for a "new look" at national defense. His administration
chose to invest in the Air Force, especially Strategic Air Command. The Air
Force retired nearly all of its B-29/B-50s, to be replaced by the new Boeing
B-47 Stratojet. By 1955, the swept wing Boeing B-52 Stratofortress was entering
the inventory in substantial numbers, replacing B-36s.

The two main factors contributing to the obsolescence of the B-36 and leading to
its phaseout we

* The Peacemaker was not designed for aerial refueling, and required
intermediate refueling bases to reach its planned targets deep in the Soviet
Union.

* Its slow speed made it vulnerable to Soviet jet interceptor aircraft, making
long-range bombardment flights over Soviet territory extremely hazardous,
seriously compromising its ability to reach its planned target and return.

The scrapping of B-36s began in February 1956. Once replaced by B-52s, they were
flown directly from operational squadrons to Davis–Monthan AFB, Arizona, where
the Mar-Pak Corporation handled their reclamation and destruction. Defense
cutbacks in FY 1958 compelled the B-52 procurement process to be stretched out
and the B-36 service life to be extended. The B-36s remaining in service were
supported with components scavenged from aircraft sent to Davis–Monthan. Further
update work was undertaken by Convair at San Diego (Specialized Aircraft
Maintenance, SAM-SAC) until 1957 to extend the life and capabilities of the
B-36s. By December 1958 only 22 B-36Js were still operational.

Specifications (B-36J-III)

General characteristics
Crew: 13
Length: 162 ft 1 in (49.42 m)
Wingspan: 230 ft 0 in (70.12 m)
Height: 46 ft 9 in (14.25 m)
Wing area: 4,772 ft² (443.5 m²)
Airfoil: NACA 63(420)-422 root, NACA 63(420)-517 tip
Empty weight: 166,165 lb (75,530 kg)
Loaded weight: 262,500 lb (119,318 kg) combat weight
Max. takeoff weight: 410,000 lb (186,000 kg)
Powerplant: 4 × General Electric J47 turbojet, 5,200 lbf (23.2 kN) each
6 × Pratt & Whitney R-4360-53 "Wasp Major" radial engine, 3,800 hp (2,835 kW)
each


Performance
Maximum speed: 435 mph (363 knots, 672 km/h)
Cruise speed: 230 mph (200 knots, 370 km/h)
Combat radius: 3,985 mi (3,465 nmi, 6,415 km)
Ferry range: 10,000 mi (8,700 nmi, 16,000 km)
Service ceiling: 43,600 ft (13,300 m)
Rate of climb: 1,995 ft/min (10.1m/s)

Armament

Guns: 1 remotely operated tail turret with 2× 20 mm (0.787 in) M24A1 autocannons
Bombs: 86,000 lb (39,000 kg) with weight restrictions, 72,000 lb (32,700 kg)
norm




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