Seven years after it set out to transfer the U.K.’s search-and-rescue (SAR) helicopter service from the Royal Air Force to a commercial contractor, the government has awarded Bristow Group a £1.6 billion ($2.4 billion) contract to operate 22 helicopters from 10 bases across the country.

U.K. subsidiary Bristow Helicopters will operate a mix of AgustaWestland AW139s and Sikorsky S-92s, replacing RAF Westland Sea Kings and AW139s and S-92s operated by Bristow and CHC Helicopter for the U.K.’s Maritime and Coastguard Agency (MCA).

The U.K. originally planned to hand over SAR helicopter operations to a commercial contractor under a long-term private finance initiative (PFI), and selected as the preferred bidder Sotera, a consortium of CHC, Thales and the Royal Bank of Scotland.

But the program was canceled in February 2011 when Sotera informed the government of irregularities in its bid. The PFI was replaced by the more conventional, but still controversial, plan to award contracts for up to 10 years of SAR helicopter operations.

Under the revised plan, the number of SAR helicopter bases is being reduced to 10 from 12, but the U.K. Department for Trade (DfT) says coverage areas and response times will improve under the new contract.

“Helicopters will be able to reach a larger area of the U.K. search-and-rescue region within one hour of takeoff than is currently possible,” says the DfT in a statement, adding there will be an overall improvement in flying times to incidents of around 20%.

“Presently, approximately 70% of high- and very-high risk areas within the U.K. search-and-rescue region are reachable by helicopter within 30 minutes. Under the new contract, approximately 85% of the same area would be reached within this time frame,” the DfT says.

Bristow will begin operations in 2015 and the service will be fully operational across the U.K. by summer 2017. RAF SAR Sea Kings are scheduled to be withdrawn from service in March 2016, while the “Gap SAR” services provided by Bristow and CHC for the MCA will run until 2017.

The S-92s will meet the requirement for a helicopter with a 200-250-nm radius of action and the ability to carry eight survivors. They will be based at Stornoway and Sumburgh, and at new SAR bases at Newquay, Caernarfon and Humberside airports.

The AW189s will meet the requirement for a smaller helicopter with a 170-nm radius and the ability to carry four survivors. They will be based at Lee on Solent and Prestwick, with new bases to be established at St. Athan, Inverness and Manston airports.

The AW189s will be assembled at AgustaWestland’s factory in Yeovil, says Transport Secretary Patrick McLoughlin, and Sikorsky will locate a supply hub in Aberdeen to support not only the U.K. SAR program but also helicopters in the offshore oil sector.