<Table> <Tr> <Th_colspan="2"> B - 52 Stratofortress </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> A B - 52H from Barksdale AFB flying over desert </Td> </Tr> <Tr> <Th> Role </Th> <Td> Strategic bomber </Td> </Tr> <Tr> <Th> National origin </Th> <Td> United States </Td> </Tr> <Tr> <Th> Manufacturer </Th> <Td> Boeing </Td> </Tr> <Tr> <Th> First flight </Th> <Td> 15 April 1952 </Td> </Tr> <Tr> <Th> Introduction </Th> <Td> February 1955 </Td> </Tr> <Tr> <Th> Status </Th> <Td> In service </Td> </Tr> <Tr> <Th> Primary users </Th> <Td> United States Air Force NASA </Td> </Tr> <Tr> <Th> Produced </Th> <Td> 1952--1962 </Td> </Tr> <Tr> <Th> Number built </Th> <Td> 744 </Td> </Tr> <Tr> <Th> Unit cost </Th> <Td> B - 52B: US $14.43 million (1956); ($99.9 million in 2016) B - 52H: US $9.28 M (1962); ($57.8 million in 2016) </Td> </Tr> <Tr> <Th> Developed into </Th> <Td> Conroy Virtus </Td> </Tr> </Table> <Tr> <Th_colspan="2"> B - 52 Stratofortress </Th> </Tr>

When was the first b 52 bomber made