The company quickly expanded overseas as well as various services, including helicopter training, oil exploration, search and rescue, and charter flights.

The company went through repeated changes in ownership during the 1980s and 1990s, leading to its acquisition by American helicopter operator Offshore Logistics in 1996, which re-branded itself as The Bristow Group in February 2006.

Bristow Helicopters Limited holds a United Kingdom Civil Aviation Authority Type A Operating Licence, it is permitted to carry passengers, cargo and mail on aircraft with 20 seats or more.

After an aggressive expansion earlier in the decade, demand was cut back as crude oil prices dropped and Bristow Group's total debt stood at $1.44 billion by 30 September 2018.

[7] In 1960, Bristow Helicopters chose to enter the African market via the acquisition of crop-spraying specialist Fison-Airwork, which had also operated in locations in Central America and the UK.

Throughout much of 1970s, Nigeria functioned as Bristow's biggest profit centre; it continued to grow through the decade via contracts from Shell, Mobil, Texaco and other companies.

Following an expansion programme, which included the building of new on-site accommodations for workers and their families, around thirty S-61N flights were routinely flying daily from Sumburgh, supported by round-the-clock maintenance coverage, at the peak of operations during the 1970s.

[citation needed] In 1986, the company began training overseas pilots at its flying school at Redhill Aerodrome; this program ran for multiple decades, being rebranded as the Bristow Academy.

[8] Starting in 1971, Bristow Helicopters began providing civilian search and rescue (SAR) services in the UK, replacing military Westland Whirlwinds with Bristow-operated Sikorsky S-55s at RAF Manston, Kent.

[7] The then-unfamiliar concept of using a private company for SAR services led to a public outcry and intense lobbying efforts thus, after three years, operations were turned back over to RAF Coastal Command.

Bristow reentered the UK's SAR sector in 1983 when it commenced operations on behalf of the Maritime and Coastguard Agency (MCA) from Sumburgh Airport; the company held the contract until 2007 and secured it again in June 2013.

[7] Over the years, Bristow's SAR units have responded to multiple incidents, including rescue efforts in the recovery of survivors of the Piper Alpha disaster.

[6] The business had also developed a worldwide presence within a similar timeframe, providing its services in the North Sea, Middle East, South America, Africa, Asia, India, Bermuda, Trinidad, Australia and New Zealand.

This allows Bristow to extend its range of services into new and developing oil and gas markets and helps provide a lower cost structure in some operating areas.

The units were located at Portland (EGDP) and Lee-on-Solent (EGHF) on the south coast of England, at Stornoway (EGPO) in the Outer Hebrides, and at Sumburgh (EGPB) in the Shetland Isles.

Southern North Sea services operate from Norwich (EGSH), Humberside (EGNJ) and Den Helder (EHKD) with its support organisation based at Redhill (EGKR).