Officially, the justification by the USAF for the new B-50 designation was made on the basis that the changes introduced by the B-29D were so major that it was essentially a completely new aircraft. The ruse worked and the B-50 survived the cutbacks to become an important component of the postwar Air Force. The decision to produce the B-50 was confirmed on May 24, 1947. From the start, the B-50 was earmarked for the atomic bombing role. This decision was prompted by the uncertain future of the Convair B-36, the first long-range heavy bomber produced as an atomic carrier. A few B-29s that had been modified to carry the atomic bomb were still available, but they were nearly obsolete and would have to be replaced by a more efficient, atomic-capable bomber pending the availability of the B-36 or another bomber truly suitable for the delivery of atomic bombs.

The B-50 was externally quite similar to the B-29, but a momentary glance was sufficient to tell the difference between the two aircraft. The traditional 24 ST aluminum structure of the B-29 was replaced by the newer 75 ST, which resulted in a wing that was 16 percent stronger than the wing of the B-29 and 600 pounds lighter. The 3500-hp R-4360 Wasp Major engines gave a power increase of 59 percent. The new engine installation was the primary external feature distinguishing the B-50 from the B-29, with the oil cooler being pulled further back on the lower part of the nacelle.

Increased weight resulted in a requirement for larger flaps and a higher vertical tail. The tall vertical tail could be folded down to permit storage in standard USAF hangars. Other features included hydraulic rudder boost and nose wheel steering, faster acting undercarriage retracting mechanism and electrical de-icing of the pilots' window through the use of conductive NESA glass. The wings and empennage were de-iced thermally by having the exhaust from three combustion heaters flow through hollow double-wall structures in the leading edges of the aerodynamic surfaces. The propellers had a reversible pitch, which allowed the use of engine power as an aid to braking on short or wet runways.

There was also some rearrangement of the crew. Despite the overall similarity of the two aircraft, only about 25 percent of the B-50 parts were interchangeable with B-29 parts. The crew complement of the B-50A was typically eleven - pilot, copilot, engineer, navigator/radar operator/bombardier, bombardier/navigator/radar operator, radio/electronic countermeasures operator, left side gunner, right side gunner, top gunner, tail gunner, plus one extra crew member.

The Boeing B-50A Superfortress had four Pratt & Whitney R-4360-35 Wasp Major 28-cylinder, four-row air cooled radials with General Electric CH-7-B1 turbo-superchargers. Its maximum speed was 385 mph at 25,000 feet and 391 mph at 30,000 feet. Cruising speed was 235 mph with a service ceiling of 37,000 feet. Combat radius was 2193 miles when loaded with 10,000 pounds of bombs; the maximum range without aerial refueling was 5230 miles. The takeoff ground run to clear a 50-foot obstacle was 7425 feet at sea level.

The B-50s wingspan was 141 feet 3 inches with a length of 99 feet 0 inches and a height of 32 feet 8 inches. Empty it weighted in at 81,050 pounds, its combat weight was 120,500 pounds and it maximum takeoff weight was 168,708 pounds. The Superfortress' maximum internal bombload was 20,000 pounds. For armament it had four 0.50-inch machine guns in the forward dorsal turret, two 0.50-inch machine guns in the rear dorsal turret, two 0.50-inch machine guns in the forward ventral turret, two 0.50-inch machine guns in the rear ventral turret, two 0.50-inch machine guns and one 20-mm cannon in the tail turret.

The first B-50A flew on June 25, 1947 and 59 more were built as standard bombers. The 60th and last example was held at the factory for modification as the YB-50C, which was intended as a prototype for the B-54A series, a further-improved version of the B-50.

The first B-50As were delivered in June of 1948 to the Strategic Air Command's 43rd Bombardment Wing, based at Davis-Monthan AFB in Arizona. This wing was assigned the mission of being the primary carrier of the atomic bomb. The Strategic Air Command had come into existence in 1946 with about 250 B-17s and B-29s as initial equipment. It had always been intended that the B-50 would be only an interim strategic bomber, pending the availability of the B-47 Stratojet. However, delays in the Stratojet program forced the B-50 to soldier on until well into the 1950s. Production of the B-50A ended in January of 1949, with delivery of the last 3 aircraft. The B-50A remained in front-line service with SAC alongside the B-36 for several years. There were some problems with cold-weather performance of the B-50A. After one B-50A had crashed in Alaska, it was found that the congealing of oil in the small-sized tubing of the aircraft's manifold pressure regulator was to blame and the regulators were modified. There were numerous engine malfunctions and the constant speed drive alternators were faulty. A deficient turbo-supercharger resulted in a short period during which the aircraft was restricted from flying above 20,000 feet. Cracking of the metal skin on the trailing edge of the wings and flaps required additional modifications. Later, failure of the rudder hinge bearing caused the temporary grounding of all B-50As. Progress in fixing these problems was made and the B-50A's performance steadily improved throughout 1949.

After a short time in service, 57 B-50As were sent to the newly opened Wichita plant to be modified as receiver aircraft using the British-developed hose tanker inflight refueling system. Using this system B-50A 46-010 "Lucky Lady II" of the 43rd Bombardment Group made the first nonstop flight around the world between February 26 and March 2, 1949, being refueled enroute by four pairs of KB-29M tankers of the 43rd Air Refueling Squadron. It took 94 hours to complete the 23,452- mile journey.

Eleven B-50As on the first contract were later modified as TB-50A bombing-navigation trainers. They were primarily intended for use as training of the crews of the B-36. The B-50As began phasing out of SAC in mid-1954, when the long-awaited B-47s finally began arriving. As obsolescence approached, all surviving B-50As were converted to KB-50J three-hose tankers.

Michael Russell Your Independent guide to Aviation Article Source: http://EzineArticles.com/?expert=Michael_Russell