Convair XC-99

The Convair XC-99, 43-52436, was a prototype heavy [Vous devez être inscrit et connecté pour voir ce lien] built by [Vous devez être inscrit et connecté pour voir ce lien] for the [Vous devez être inscrit et connecté pour voir ce lien]. It was the largest piston-engined land-based transport aircraft ever built, and was developed from the [Vous devez être inscrit et connecté pour voir ce lien] bomber, sharing the wings and some other structures with it. The first flight was on 23 November 1947 in [Vous devez être inscrit et connecté pour voir ce lien], and after testing it was delivered to the Air Force on 23 November 1949.

Design and development
Design capacity of the XC-99 was 100,000 lb (45,359 kg) of cargo or 400 fully equipped troops on its double cargo decks; a cargo lift was installed for easier loading.

Operational history
In July 1950 the XC-99 flew its first cargo mission, "Operation Elephant". It transported 101,266 pounds of cargo, including engines and propellers for the B-36, from [Vous devez être inscrit et connecté pour voir ce lien] to [Vous devez être inscrit et connecté pour voir ce lien] in [Vous devez être inscrit et connecté pour voir ce lien], a record it would later break when it lifted 104,000 lb (47,174 kg) from an airfield at 5,000 ft (1,500 m) elevation. In August 1953, the XC-99 would make its longest flight, 12,000 mi (19,000 km), to [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], by way of [Vous devez être inscrit et connecté pour voir ce lien] and the [Vous devez être inscrit et connecté pour voir ce lien]. It carried more than 60,000 lb (27,216 kg) each way. It attracted much attention everywhere it flew.
The US Air Force determined that it had no need for such a large, long-range transport at that time, and no more were ordered. The sole XC-99 served until 1957, including much use during the [Vous devez être inscrit et connecté pour voir ce lien]. It made twice weekly trips from Kelly AFB to the aircraft depot at [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], transporting supplies and parts for the B-36 bomber while returning by way of other bases or depots making pick-ups and deliveries along the way. During its operational life the XC-99 logged over 7,400 hours total time.

Retirement and display
The aircraft was put on display at [Vous devez être inscrit et connecté pour voir ce lien] near [Vous devez être inscrit et connecté pour voir ce lien]. During the 1960s, it was considered for restoration by the San Antonio Air Logistics Center at Kelly AFB, but the deterioration of the airframe due to the high [Vous devez être inscrit et connecté pour voir ce lien] content led to the abandonment of that plan. The airplane was later on moved to a grassy field near the base. In 1993, the USAF moved it back to the Kelly AFB [Vous devez être inscrit et connecté pour voir ce lien] (29°22'27.37"N 98°35'13.74"W). It was planned to move the via road to the [Vous devez être inscrit et connecté pour voir ce lien] at [Vous devez être inscrit et connecté pour voir ce lien], Ohio, restore and reassemble it, and put it on display in the USAF Museum's collection of experimental aircraft. Ultimately, transporting the massive aircraft by ground proved impractical and too expensive.
1995 [Vous devez être inscrit et connecté pour voir ce lien] (BRAC) action resulted in the partial closure and realignment of Kelly AFB, with most of the former San Antonio Air Logistics Center becoming civilianized and renamed [Vous devez être inscrit et connecté pour voir ce lien], while the runway and those flight line areas supporting [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] flight operations of the [Vous devez être inscrit et connecté pour voir ce lien]'s [Vous devez être inscrit et connecté pour voir ce lien] and the [Vous devez être inscrit et connecté pour voir ce lien]'s [Vous devez être inscrit et connecté pour voir ce lien] reverted to adjacent [Vous devez être inscrit et connecté pour voir ce lien] and was renamed Lackland AFB/Kelly Field Annex.
Disassembly of the aircraft began at Kelly Field in April 2004. Portions of the airframe were then airlifted from Kelly to [Vous devez être inscrit et connecté pour voir ce lien] near [Vous devez être inscrit et connecté pour voir ce lien].^{[Vous devez être inscrit et connecté pour voir ce lien]} Upon arrival at Wright-Patterson's active base, the parts had to be further moved by truck several miles to the Museum side of the base. Transporting the XC-99 components taxed the C-5A's cargo capacity, as the largest piece moved intact was over 75 feet by 13 feet. As of summer 2008, the XC-99 has been completely transferred to [Vous devez être inscrit et connecté pour voir ce lien] and is laying on the ramp outside the Museum's restoration facility.^{[[Vous devez être inscrit et connecté pour voir ce lien]]} Upon examination, the aircraft was found to have suffered from considerable corrosion, which was not unexpected considering it had remained outside for over fifty years. The wing spar was found to be too badly corroded to restore, and a new replacement will have to be fabricated. A full restoration is expected to be performed by the restoration crew of the [Vous devez être inscrit et connecté pour voir ce lien], though no timetable exists at this time. Following restoration, the aircraft is expected to be displayed inside in one of the Museum's new hangars. Like its relative the B-36, it is expected to become a showpiece of the Museum. Once all aircraft have been moved from the Museum's current "Research and Development Hangar" to a new display hangar planned to be added onto the main Museum buildings, the XC-99 restoration project will move into the former R&D Hangar where visitors will be able to watch the restoration in progress.[Vous devez être inscrit et connecté pour voir ce lien] Upon completion, the XC-99 will remain on display in the former R&D hangar.
Pending the restoration and display of the XC-99, in an effort to educate visitors about the aircraft the [Vous devez être inscrit et connecté pour voir ce lien] has placed a model of the XC-99 on display in its Post-Cold War Gallery. The model, in approximately 1/72 scale, was constructed by a member of the Museum's restoration staff. An explanation of the Museum's plans for the restoration and display of the XC-99 is located in the case with the model.

Civil variant
A civil variant of the XC-99, the Convair Model 37 was a large passenger aircraft which was planned but never built. The Model 37 was to be of similar proportions to the XC-99; 182 ft 6 in (55.63 m) length, 230 ft (70 m) wingspan, and a high-capacity, double-deck fuselage. The projected passenger load was to be 204, and the effective range 4,200 mi (6,800 km).
15 aircraft were ordered by [Vous devez être inscrit et connecté pour voir ce lien] for transatlantic service.
Unfortunately for the project, the fuel and oil consumption of the six 3,500 hp (2,600 kW) Wasp Major radials powering the XC-99 and B-36 meant that the design was not economically viable, and hoped-for [Vous devez être inscrit et connecté pour voir ce lien] powerplants did not materialise fast enough. 15 orders were not sufficient for production, and the project was abandoned.

Specifications (XC-99)

General characteristics

• Crew: Five
  
• Capacity: 400 troops
  
• Payload: 100,000 lb (45,000 kg)
  
• Length: 185 ft (56.4 m)
  
• [Vous devez être inscrit et connecté pour voir ce lien]: 230 ft (70.10 m)
  
• Height: 57 ft 5 in (17.50 m)
  
• Wing area: 4,772 ft² (443.3 m²)
  
• [Vous devez être inscrit et connecté pour voir ce lien]: 320,000 lb (145,000 kg)
  
• Powerplant: 6× [Vous devez être inscrit et connecté pour voir ce lien] Wasp Major radial piston engines, 3,500 hp (2,600 kW) each
  
  Performance
  
  
• Range: 8,000 mi (13,000 km)

The XC-99, serial 43-52436, is a double deck transport variant of the B-36. It has a considerably larger fuselage, but was never fitted with jet pods. The wingspan is the same 230 feet, but the fuselage is 23 feet longer at 185 feet. The payload of the XC-99 was 101,000 pounds or 400 fully equipped troops. It was delivered to the Air Force on November 23, 1949.

The Wright Field arrow has been applied to the vertical stabilizer of the XC-99 and United States Air Force has been painted on the side of the fuselage. The lack of a bulge over the landing gear well indicates that the XC-99 is still equipped with the single wheel main landing gear.

The XC-99 has been retrofitted with four wheel main landing gear bogies like those used on production B-36s, but it has not yet had its nose radar installed.

The Convair model 37 was a proposed a 204-seat airliner version of the XC-99. Pan American Airlines ordered fifteen Model 37 twin-deck airliners. They would have provided capacious restrooms and lounges for their transatlantic passengers

Contemporary magazine article about the Convair Model 37:

No one knows when or where the legend of Pegasus first became popular. Nor does the date really matter. For as long as history records, men of the world have seen the flying beast of burden as the epitome of mortal ambition. Now Consolidated-Vultee has come forward with a single vehicle which moves through the air on the power of 30,000 winged horses-to prove conclusively that the sky alone is the limit where practical airplane size is concerned.
That the recently announced Model 37 is far and away the largest flying machine on the immediate post-war docket is obvious. Although size alone does not spell greatness in aviation, it is interesting to note that the single slender wing of the Model 37 would outreach a 21-story building if upended on a metropolitan street corner. Similarly, the single fin and rudder stands approximately five stories above the runway. Twice as large as the Consolidated-Vultee Liberator, the Model 37 has a wing span of 230 feet and measures 182 feet in length. Nearly ten Piper Cubs could be parked in the tarmac space occupied by a single Model 37.
Actually this new transport is something more than a very large airplane, with external lines and internal design unlike anything previously offered to the commercial airline operators of the world. It has, first of all, six engines buried in the wing to match the largest pre-war German, French and Russian commercial types in number of engines. Unlike the latter types, however, the Model 37 carries the engines in the trailing edge of the wing and becomes the first pusher type likely to see commercial service. Because the Model 37 is derived from a new Consolidated design, all information on power plants is necessarily restricted at the present time. However, the manufacturer has announced total power output equal to that of 353 automobiles-approximately 30,000 hp if we accept 85 hp as the average for American motor cars. It would be possible to obtain this output in one of two ways. The Model 37 may have a pair of inline engines in each nacelle, with a long uni-twin head and shaft driving the three-blade propellers. Or it may be fitted with individual engines each developing 5,000 hp for take-off. The former would seem impractical in the light of Consolidated's thin wing with maximum camber inadequate for accommodation of the Allison 3420, the only announced inline, which develops more than 2,500 hp. It is possible that wartime ingenuity has brought radial engines which develop considerably more than the 3,000 hp announced some time ago. However, air-cooled engines, never too successful in pusher mountings, could hardly obtain sufficient cooling on the ground while buried in the Model 37 wing. So this sky gargantua is probably powered by either a gas turbine or a diesel engine of 5,000 hp efficiency-a remarkable power plant if it exists.
In operation, the Model 37 follows a performance pattern which is more Or less general in projected multi-engine transports, although its load is obviously greater than that of the Boeing Stratocruiser, the Douglas DC-7, the Lockheed Constellation, and the Martin Mars. Cruising at speeds between 310-342 mph, the big ship will carry a payload of 50,000 pounds composed of 204 passengers and seven and one-half tons of mail or express. Operating above the weather at 30,000 feet, the Model 37 is designed for a range of 4,200 miles with the previously-mentioned load. A double-deck interior will embrace two-passenger staterooms, oversize berths, two lounges, and a number of rest rooms, with Henry Dreyfuss interiors assuring color and comfort for passengers on the long over-water routes.

Model 37 Cancellation

The intended powerplant for the Model 37 was a 5,000 horsepower gas turbine engine which failed to materialize. The fuel and oil consumption of the 3,500 horsepower R-4360 radial engines made the design unprofitable. In addition, it was felt that the airplane provided too much capacity for the level of airline traffic that was forecast at the time.
Imagine what post-war airline travel would have been like if the Allison T-56 turbo-prop had been available at the time. Today, there would still be huge Model 37s carrying oversize cargo for Heavylift, dropping vast quantities of retardent on forest fires, and rotting on the backside of the Mojave Airport.