Closely reFor the military versions and operators, see UH-1N Twin Huey. Based on the stretched fuselage Bell 205, the Bell 212 was originally developed for the Canadian Forces as the CUH-1N and later redesignated as the CH-135. The Canadian Forces took delivery of 50 starting in May 1971. At the same time the United States military services ordered 294 Bell 212s under the designation UH-1N. By 1971 the 212 had been developed for commercial applications. Among the earliest uses of the 212 in civil aviation was by Helicopter Service AS of Norway to be used in support of offshore oil rigs. Today the 212 can be found used in logging operations, maritime rescue and resupply in the Arctic on the Distant Early Warning Line or North Warning
The 212's main rotor is powered by a Pratt & Whitney Canada PT6T-3 Twin-Pac made up of two coupled PT6 power turbines driving a common gearbox. System.
They are capable to maintain cruise performance at maximum weight. Early 212s configured with an Instrument Flight Rules (IFR) instrument package were required to have a large and very obvious fin attached to the roof of the aircraft, above and slightly behind the cockpit. This fin was initially determined necessary to alter the turning performance of the aircraft during complex instrument flight maneuvers, but now not required due to revised stipulations of the type certificate. Many aircraft still fly with the modification.
Bell developed the Model 212 further with the Bell 412; the major difference being the composite four-blade main rotor. The last Bell 212 was delivered in 1998.