Convair 37 / B-36
The first intercontinental bomber, the Convair B-36 originated from a US Army Air Force specification issued on 11 April 1941 which called for an aircraft with ability to carry a maximum bombload of 72,000 lb / 32659kg and to deliver 10,000-lb / 4536kg of bombs on European targets from bases in the United States. A radius of 5000 miles / 8047 km. An unrefuelled range of 16093km was a prime requirement, with a maximum speed of 386-483 km/h and ceiling of 35000 ft / 10670m.
A number of designs were submitted and the winner was selected in November 1941 the month before the USAs entry into World War II. It was the Consolidated Model 37, which was ordered in prototype term as the XB-36, becoming the developmental YB-36 trials model, finally built by Convair, as Consolidated became known after its merger with Vultee.
The design was basically conventional by the standards of the time, but with a span of 230 ft (74.10 m) the aeroplane was exceptionally large weighing 102 tonnes (100 tons). The tyres on the prototypes main landing gear were 2.74 m (9 ft) in diameter (they also concentrated too much weight on the runways of the day, and were replaced on production aircraft by four-wheel bogie units). The original single‑wheel main undercarriages smashed up run way surfaces. The type did introduce some novel features, however, including a slightly swept wing, a fuselage whose two main pressurized compartments were connected by an 80-ft (24.4m) tunnel containing a wheeled cart, and propulsion by six pusher propellers driven by radial engines buried in the thick wings. The wings had a root thickness of 1.83m to permit in-flight access to the six pusher engines. The B‑36 used the "wet fuel tankage” pioneered by Consolidated with their B~24 liberator ‑ no fuel tanks as‑such, just big areas of the wing structure sealed and filled with fuel.There were leakage problems. The aircraft was designed originally with twin fins and rudders, but by the time the XB-36 prototype was ready to be rolled out at Fort Worth, on 8 September 1945, single vertical tail surfaces had been substituted. The aircrafts tailfin was so tall that the nosewheel had to be jacked up to lower the rear and clear the top of the doors.
B-36 Peacemaker required a crew of 11 personnel to maintain all systems and weaponry on the aircraft with 4 'relief' personnel flying along as well.
Defensive armament consisted of sixteen 20mm cannon emplacements in the nose, tail and throughout the fuselage in barbettes - though this defensive armament was not added till the B-36B models.
The prototype programme was initially slowed by World War II’s demands for current aircraft, but then placed at the highest priority in 1943 when the USA realized that strategic blows against Japan could only be struck by long-range strategic bombers.
First flown on 8 August 1946, the XB-36 had single 2.79m diameter main wheels, also a feature of the YB-36 second prototype on which they were replaced later by the four-wheeled bogies adopted for production aircraft. In this form the aircraft was designated YB-36A and also differed from the first aircraft by introducing a raised cockpit roof. On 23 July 1943 100 aircraft were ordered but it was more than four years before the first of the 22 unarmed crew-trainer B-36A models took off on its maiden flight, on 28 August 1947.
The Convair B-36 Peacemaker entered service with the United States Air Force’s 7th Bombardment Wing (Heavy) on 2 June 1948.
From 1950 the over-target height and speed were boosted by adding four 2360-kg (5200-lb) thrust J47 jet engines in under- slung pods to boost performance; with the six piston engines also uprated to 3800 hp each. Missions could last up to 50 hours without using the inflight-refuelling capability. Complete wings were based in the UK, Morocco, Guam and other areas, as well as in the USA until February 1959. No missions were flown 'in anger'. There were high maintenance costs. Every flight ‑ up to 40 hours aloft ‑ cost thousands of man‑hours on the ground. For instance, every flight began with a new set of sparkplugs in the engines: 336 of them in 168 cylinder‑heads on six engines.
In its final production version the B-36 had a combat overload weight of 208 tonnes (205 tons), more than double that of the prototype, and a maximum flight duration of 42 hours. An arsenal of 16 guns was carried, and crews numbered between 13 and 22 men, depending on the model and type of mission, some of which involved high-altitude over-flights of the Soviet Union.
The last B-36J was delivered in September 1953 and the ultimate operational B-36 was retired in August 1959. The GRB-36 operated as an airborne aircraft carrier. When the Convair B-36 Peacemaker bomber went into service with the United States Air Force's Strategic Air Command, plans were laid for two hook-on projects. The first of these was a fighter called the McDonnell XF-85 Goblin, which was 4.57 m (15 ft) long. The Goblin was to have been carried in the B-36's bomb-bay ready for launching in the event of fighter attack. Having won the ensuing dogfight it would then rejoin the mother ship for it did not give it any landing gear of its own.
Convair B-36J Peacemaker
The second attempt to use the B-36 as an aircraft-carrier took place in 1955 and 1956. Seeking a reconnaissance aircraft with sufficient range to reach the Soviet Union, the USAF came up with FICON, which stood for Fighter In CONvair. By hitching a Republic RF-84 Thunderflash to a B-36, the photo-reconnaissance jet's range could be extended from 3220 km (2000 miles) to 19,310 km (12,000 miles). Some thought was also given to a nuclear-bomb equipped Thunderstreak substituting for the Thunderflash. Twenty-five RF-84Fs were modified for parasite duty. On a typical mission the mother ship B-36 would depart from Fairchild Air Force Base, Spokane, Washington to be joined in the air by an RF-84K (as the parasite Thunderflashes were designated) from Moses Lake Air Force Base. The fighter would be hoisted into the B-36's bomb bay.
In April 1945 the USAF’s predecessor, the USAAF, had issued its specification for a B-35/B-36 replacement with turbine propulsion, and the USAF pushed this programme with considerable vigour. The failing submission to the 1945 requirement was the Convair YB-36G, which was redesignated YB-60 before two prototypes were ordered in March 1951,
Two Convair X-6s were ordered to evaluate the operational practicality of airborne nuclear propulsion systems prior to committing to building a prototype of a dedicated military design. The specific areas to be tested included crew shielding, propulsion, radiobiology, and the effects of radiation on various aircraft systems.
In addition to the X-6s, a single NB-36H was ordered to serve as an early flyable testbed. In the NB-36H, the nuclear reactor was functioning but provided no power to the aircraft itself. The X-6s would have been powered by a prototype airborne nuclear propulsion system installed in the aft bomb bays.
In the end, the X-6 program was cancelled before either of the two aircraft were built. The NB-36H was completed, however, making its first flight in September 1955. After conducting tests for approximately two years, the nuclear reactor was removed and the NB-36H was scrapped at Carswell AFB, Texas.
The B‑36 was used as an extreme‑range spy plane (the version carried a photographic work shop instead of the usual bombload).
Production of the B-36 continued for almost seven years, the last of 385 examples being delivered to Strategic Air Command on 14 August 1954, and the type was retired finally on 12 February 1959.
Engines: 6 x P+W R-4360, 2575kW
Wingspan: 70.1 m / 229 ft 12 in
Length: 49.4 m / 162 ft 1 in
Height: 14.3 m / 46 ft 11 in
Wing area: 443.3 sq.m / 4771.64 sq ft
Max take-off weight: 162162 kg / 357508 lb
Empty weight: 72051 kg / 158846 lb
Max. speed: 696 km/h / 432 mph
Cruise speed: 362 km/h / 225 mph
Ceiling: 13700 m / 44950 ft
Range w/max.fuel: 16000 km / 9942 miles
Armament: 12-16 20mm machine-guns, 32600kg of bombs
Convair B-36D Peacemaker
Engines: 6 x 3,500 hp Pratt & Whitney R-4360-41 radials + 4 GE J47-GE-19 turbojet, 5,200 lb. thrust
Length: 162.07ft (49.4m)
Width: 229.66ft (70.00m)
Height: 46.75ft (14.25m)
Maximum Speed: 439mph (706kmh; 381kts)
Maximum Range: 7,500miles (12,070km)
Service Ceiling: 45,197ft (13,776m; 8.6miles)
Armament: 12 x 20mm cannons in nose, tail and fuselage barbettes
Up to 86,000 lbs of bombs internally.
Empty Weight: 171,035lbs (77,580kg)
Maximum Take-Off Weight: 418,878lbs (190,000kg)
Engines: 6 x Pratt & Whitney R-4360-53 Wasp Major 28-cylinder radial, 3,800-hp (2834-kW) and 4 x General Electric J47-GE-19 turbojets, 2359-kg (5.200-lb).
Max speed: 661 km/h (411 mph) at 11095 m (36,400 ft).
Over-target height: up to 12160 m (39,900 ft).
Range with 4990-kg (11,000-lb) bombload: 10944 km (6,800 miles).
Empty weight: 77581 kg (171,035 lb)
Maximum take-off weight: 185976 kg (410,000 lb).
Wing span 70,10 m (230 ft 0 in).
Length 49.40 m (162 ft 1 in).
Height 14.23 m (46 ft 8 in).
Wing area 443.3 sq.m (4,772.0 sq ft).
Armament: 16 x 20-mm cannon in 8 turrets
Bombload: up to 39010 kg (86, 000 lb).