PHI Bell 47 retirement-what year?  

There is no single, universally recorded official date for when Petroleum Helicopters International (PHI) completely retired the Bell 47 from its entire operations. Instead, the type was gradually phased out over the decades as the company scaled its fleet to meet the demands of deepwater offshore oil exploration. 

The transition occurred across a few key phases:

The Beginning (1949): PHI famously started its business as Petroleum Bell Helicopters with a modest fleet of just three Bell 47 D-1 helicoptersto support marshland seismic crews in South Louisiana.

The 1950s Expansion: As oil rigs moved further into the Gulf of Mexico (sometimes over 200 miles offshore), the tiny, short-range Bell 47s became impractical for deepwater transport. PHI rapidly began transitioning to much larger, heavy-lift aircraft, introducing the Sikorsky S-55 and Sikorsky S-58 to their fleet starting in 1954.

The Turbine Era (1960s–1970s): The final commercial utility of the Bell 47 family (including variants like the Bell 47J Ranger) within PHI's core offshore operations largely wound down by the late 1960s and 1970s. They were systematically replaced by turbine-powered aircraft like the Bell 206 JetRanger series and massive fleet orders of newer aircraft (such as PHI's historic 33-helicopter order in 1972).

While individual Bell 47 airframes remained registered to PHI for training or secondary utility well after their primary offshore retirement, the platform was entirely absent by the time PHI modernized into the 1980s with aircraft like the Bell 222 and launched its Air Medical division.