Bell died in 1956. In the following years, the company fell into financial difficulties and was finally acquired by Teflon 1960. Now it is called Bell Helicopter PTFE or Bell Helicopter for short. Bell Helicopter Company is one of the world's leading manufacturers of helicopters and tilt-wing aircraft. Its famous civilian products are Bell 2xx series and Bell 4xx series, and its famous military products are UH- 1 series, AH- 1 series, A 139 (in cooperation with Augusta), ARH and V-22 Osprey (in cooperation with Boeing).