Canada and Sikorsky have finally agreed the contract amendments required to allow the acquisition and support of the country's serially delayed CH-148 Cyclone maritime helicopters.

However, under the terms of the modified agreement the Royal Canadian Air Force will not receive a fully capable rotorcraft before 2018 – 10 years later than originally planned.

Frequently cited as one of the worst examples of military procurement, the resolution of the long-running saga surrounding the Cyclone has become critical for Ottawa, as the RCAF’s fleet of CH-124 Sea Kings begins to show their age.

Covering a total of 28 helicopters, Canada will spend C$1.9 billion ($1.8 billion) to acquire the CH-148s – a militarised variant of the commercial S-92 – and a further C$5.7 billion maintaining them until 2038. The original 2004 contract included maintenance costs of C$3.2 billion over a 20-year period.

The RCAF will begin retiring its Sea Kings from 2015, as Cyclones with “operational capability” arrive. So far the service has received four helicopters in an interim configuration, but further deliveries stalled as Sikorsky was unable to produce an acceptable aircraft.

Faced with a contract that appeared to be undeliverable, Ottawa briefly toyed with cancelling the purchase and instead acquiring a different model from Airbus Helicopters or AgustaWestland.

However, a report from Hitachi Consulting produced for procurement body Public Works Government Services Canada concluded late last year that the deal with Sikorsky could be salvaged, provided a new governance structure was put in place.

This led to the two sides agreeing principles of agreement on a revised contract in January.

Hitachi will continue to oversee aspects of the acquisition, “ensuring that delivery times remain as promised for the RCAF”, PWGSC says.