|Bell Model 47D / H-13B / HTL-2|
Early in 1948, the Model 47B was superseded by the Model 47D which incorporated a number of improvements, the most apparent being the plastic bubble-like cabin, the top of which could be removed to provide an open cockpit. In 1949, a new sub-variant appeared, the Model 47D-1 utility helicopter capable of carrying three people or 225kg of payload. The same year, Bell helicopters began to be used on air mail services in Chicago and a Bell 47 set a new altitude record with 5654m as well as a new speed record with 215.45km/h. In 1950, a Bell 47D-1 became the first helicopter to fly over the Alps, and in Belgium the first European postal service by heli-copter was set up by Sabena on 21 August, 1950. At the end of the same year, Bell 47s were used to take precise measurements over the Niagara Falls. But these were not the last achievements of the Goldfish bowl, as the Bell aircraft began to be known. On 17 September, 1952, Bell pilot, Eiton J. Smith set the world's straight line distance record for helicopters without payload (Class-E) at the controls of a Model 47D-1 registered N167B, flying nonstop from Hurst (Texas) to Buffalo (New-York): 1958.37km in 12hr 57min. On 2 September, 1956, at the National Aircraft Show in Oklahoma City, an H-13H flown by an Army pilot stayed in the air for 57hr and 50min, an unofficial world's record.
A.J.Pelletier "Bell Aircraft since 1935", 1992
Technical data for Model 47D-1
Number of seats: 3, rotor diameter: 10.72m, overall length: 12.56m, fuselage length: 8.33m, height: 2.79m, loaded weight: 943kg, empty weight: 626kg, maximum cruising speed at sea level: 147km/h, rate of climb: 313m/min, service ceiling: 3965m, hover ceiling in ground effect: 1920m, range (75% power): 342km