Boeing B-50 Superfortress

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The [Vous devez être inscrit et connecté pour voir ce lien] B-50 Superfortress strategic bomber was a post-[Vous devez être inscrit et connecté pour voir ce lien] revision of the [Vous devez être inscrit et connecté pour voir ce lien], fitted with more powerful [Vous devez être inscrit et connecté pour voir ce lien], stronger structure, a taller fin, and other improvements. It was the last piston-engined bomber designed by [Vous devez être inscrit et connecté pour voir ce lien] for the [Vous devez être inscrit et connecté pour voir ce lien].

Not as well known as its direct predecessor, the B-50 was in USAF service for nearly 20 years.

After its primary service with SAC ended, B-50 airframes were modified into aerial tankers for [Vous devez être inscrit et connecté pour voir ce lien] (KB-50) and as weather reconnaissance aircraft (WB-50) for the [Vous devez être inscrit et connecté pour voir ce lien].

Both the tanker and hurricane hunter versions were retired in March 1965 due to metal fatigue and corrosion found in the wreckage of KB-50J, 48-065, which crashed on 14 October 1964.

Design and development

Development of an improved B-29 started in 1944, with the desire to replace the unreliable [Vous devez être inscrit et connecté pour voir ce lien] engines with the more powerful four-row, 28-cylinder [Vous devez être inscrit et connecté pour voir ce lien] Wasp-Major [Vous devez être inscrit et connecté pour voir ce lien].

A B-29A-5-BN ([Vous devez être inscrit et connecté pour voir ce lien] 42-93845) was modified by [Vous devez être inscrit et connecté pour voir ce lien] as a testbed for the installation of the R-4360 in the B-29, with four 3,000 [Vous devez être inscrit et connecté pour voir ce lien] (2,240 kW) R-4630-33s replacing the 2,200 horsepower (1,640 kW) R-3350s.

The modified aircraft, designated [Vous devez être inscrit et connecté pour voir ce lien], first flew in May 1945.

The planned Wasp-Major powered bomber, the B-29D, was to incorporate considerable changes in addition to the engine installation tested in the B-44.

The use of a new alloy of [Vous devez être inscrit et connecté pour voir ce lien], 75-S rather than the existing 24ST, gave a wing that was both stronger and lighter, while the undercarriage was strengthened to allow the aircraft to operate at weights of up to 40,000 pounds (18,200 kilograms) greater than the B-29. A larger vertical fin and rudder (which could fold to allow the aircraft to fit into existing hangars) and enlarged flaps were provided to deal with the increased weight.

Armament was similar to that of the B-29, with two bomb bays carrying 20,000 pounds (9,100 kg) of bombs, and a further 8,000 pounds (3,600 kg) externally.

Defensive armament was 13 × .50 in (12.7 mm) machine guns (or 12 machine guns and one 20 mm cannon) in five turrets.

First flying in May 1945, the XB-44 proved 50-60 mph faster than the B-29 (available sources do not indicate how much of this increased speed was due to differing aircraft weight or to deleted armament).

Only the one aircraft was used in the B-44 flight test program.

An order for 200 B-29Ds was placed in July 1945, but the ending of [Vous devez être inscrit et connecté pour voir ce lien] in August 1945 prompted mass cancellations of outstanding orders for military equipment, with over 5,000 B-29s cancelled in September 1945.

In December that year, B-29D orders were cut from 200 to 60, while at the same time the designation of the aircraft was changed to B-50.

Officially, the aircraft's new designation was justified by the changes incorporated into the revised aircraft, but according to [Vous devez être inscrit et connecté pour voir ce lien], a long-time Boeing employee and aircraft designer, and a well-known authority on Boeing aircraft, "the redesignation was an outright military ruse to win appropriations for the procurement of an airplane that by its B-29D designation appeared to be merely a later version of an existing model that was being canceled wholesale, with many existing examples being put into dead storage."

The first production B-50A (there were no prototypes, as the aircraft's engines and new tail had already been tested) made its maiden flight on June 25, 1947, with a further 78 B-50As following.

The last airframe of the initial order was held back for modification to the prototype YB-50C, a planned version to be powered by R-4360-43 [Vous devez être inscrit et connecté pour voir ce lien].

It was to have a longer fuselage, allowing the two small bomb-bays of the B-29 and the B-50A to be replaced by a single large bomb-bay, more suited to carrying large nuclear weapons.

It would also have longer span wings, which required additional outrigger wheels to stabilize the aircraft on the ground.

Orders for 43 B-54s, the planned production version of the YB-50C, were placed in 1948, but the program was unpopular with [Vous devez être inscrit et connecté pour voir ce lien], commander of [Vous devez être inscrit et connecté pour voir ce lien] (SAC), as being inferior to the [Vous devez être inscrit et connecté pour voir ce lien] and having little capacity for further improvement, while requiring an expensive redevelopment of air bases owing to the type's undercarriage.

The B-54 program was therefore canceled in April 1949, work on the YB-50C being stopped prior to it being completed.

While the B-54 was canceled, production of less elaborate developments continued as a stopgap until jet bombers like the [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] could enter service.

Forty-five B-50Bs, fitted with lightweight fuel tanks and capable of operating at higher weights, were built, followed by 222 B-50Ds, capable of carrying underwing fuel tanks and distinguished by a one-piece plastic nose dome.

To give the Superfortress the range to reach the [Vous devez être inscrit et connecté pour voir ce lien], B-50s were fitted to be [Vous devez être inscrit et connecté pour voir ce lien].

Most (but not all) of the B-50As were fitted with the early "looped hose" refueling system, developed by the British company [Vous devez être inscrit et connecté pour voir ce lien], in which the receiving aircraft would use a grapple to catch a line trailed by the tanker aircraft (normally a [Vous devez être inscrit et connecté pour voir ce lien]) before hauling over the fuel line to allow transfer of fuel to begin.

While this system worked, it was clumsy, and Boeing designed the alternative [Vous devez être inscrit et connecté pour voir ce lien] method to refuel SAC's bombers, with most B-50Ds being fitted with receptacles for Flying Boom refueling.

Revisions to the B-50 (from its predecessor B-29) would boost top speed to just under 400 mph (644 km/h). Changes included:

• Larger engines
  
• Redesigned engine nacelles and engine mounts
  
• Enlarged vertical tail and rudder (to maintain adequate yaw control during engine-out conditions)
  
• Reinforced wing structure (required due to increased engine mass, larger gyroscopic forces from larger propellers, greater fuel load, and revised landing gear loading)
  
• Revised routing for engine gases (cooling, intake, exhaust and intercooler ducts; also oil lines)
  
• Upgraded remote turret fire-control equipment
  
• Landing gear strengthened and takeoff weight increased from 133,500 lb / 60,555 kg to 173,000 lb / 78,471 kg
  
• Increased fuel capacity with underwing fuel tanks being added.
  
• Improvements to flight control systems (the B-29 was difficult to fly; with increased weights the B-50 would have been more so).
  

Redesigned with a large upper fuselage grafted on, the B-50 design would form the basis for the [Vous devez être inscrit et connecté pour voir ce lien] series of airliners and [Vous devez être inscrit et connecté pour voir ce lien]/[Vous devez être inscrit et connecté pour voir ce lien] military transports, with 816 of the KC-97 built. The B-29 and B-50 were phased out with introduction of the jet-powered [Vous devez être inscrit et connecté pour voir ce lien]. ^{[Vous devez être inscrit et connecté pour voir ce lien]}

The B-50 was nicknamed "[Vous devez être inscrit et connecté pour voir ce lien]" because the redesigned engine nacelles reminded aircrew of the chinless newspaper comic character popular at the time.

KB-50 tankers


The Boeing KB-50 was a modified Boeing B-50 Superfortress for [Vous devez être inscrit et connecté pour voir ce lien] needs by the [Vous devez être inscrit et connecté pour voir ce lien]. Two primary tanker versions were developed and produced, the KB-50J and the KB-50K.

After the promising results from the KB-29 conversions the USAF recognized the need for a tanker with higher performance and more room for off-loading fuel.

Soon after entering service as strategic bombers plans were made for converting 134 B-50s, made up of B-50As, RB-50s, and B-50Ds, into aerial refueling tankers when no longer needed by [Vous devez être inscrit et connecté pour voir ce lien] bomber forces.

As tankers, KB-50s would feature extensively reinforced outer wing panels, as well as the necessary equipment to air refuel simultaneously three fighter-type aircraft by the [Vous devez être inscrit et connecté pour voir ce lien] method.

The modifications, assigned to the Hayes Aircraft Corporation, also included deletion of the B-50 defensive armament and replacement of the aircraft's tail section.

Although the completion date of the Hayes modification was tentatively set for December 1957, the project (ordered
in the mid-1950s) proceeded so well that it was ended ahead of schedule.

The first KB-50 flew in December 1955 and was accepted by the Air Force in January 1956.

The tankers steadily entered the operational inventory of [Vous devez être inscrit et connecté pour voir ce lien] (TAC) supplanting TACs [Vous devez être inscrit et connecté pour voir ce lien].

By the end of 1957 all of the command's aerial refuling squadrons had their full complement of KB-50s.

TAC had nothing but praise for the new tankers; the KB-50s presented no serious problems, and their reliability was such that the command considered asking for more of them.

Extra KB-50s would come "cheap," TAC calculated, if additional numbers of B-50s were added to the Hayes modification line.

Nevertheless, the recommendation remained in limbo, which was just as well since the modification line had already been closed and the superior KB-50J was on the way.

Variants

XB-44

One B-29A was handed over to [Vous devez être inscrit et connecté pour voir ce lien] to be used as a testbed for the installation of the new [Vous devez être inscrit et connecté pour voir ce lien] 28-cylinder engines in the B-29.

B-29D

Wasp Major powered bomber, with stronger structure and taller tail. Redesignated B-50A in December 1945.