The Mk5s have the potential to bring a significant capability to the Chinook force. Since they were returned to operational service the Mk3s have been mainly used for training, but with the upgrade and the variant's enlarged fuel sponsons, the aircraft could deliver useful range and payload improvements for ferrying or long-endurance capability.

The 14 new aircraft ordered in August 2011 are being built in Philadelphia by Boeing and will be designated Mk6s. These are essentially CH-47Fs but will feature the same Thales cockpit as the rest of the fleet, as well as a Digital Automatic Flight Control System that allows features such as auto-hover to be enabled. The first of the Mk6s is due to arrive in the U.K. in 2014.

The first Mk4s became operational in summer 2012 and supported the Olympic security operation. As part of the preparation for Afghanistan, several aircraft were sent to El Centro, Calif., where crews were able to practice brown-out landings. On Dec. 12, Mk4s were transported to Afghanistan, where they are now operational. As more upgraded aircraft arrive, crews and instructors are being schooled in their use. Training frontline crews takes around two months, with ground school and then hands-on practical experience split 50/50 between the simulator and the aircraft.

“The aircraft handles in exactly the same way as the basic Chinook, so the key thing is getting the crews into using the avionic systems,” says Toriati. “They recognize that the Mk4 is a step forward and [people who] have converted have adapted very well.”

Chinooks are deployed as part of the Joint Helicopter Force (Afghanistan) supporting coalition troops in Helmand Province, and the mission there has dominated Chinook force life for the past decade. But now commanders are looking at how to rebuild the Chinook's contingency role when the Afghanistan mission ceases at the end of 2014. Toriati is considering restoring cold weather training in Norway and the option of being able to operate from ships. Chinooks are already supporting Joint Warrior exercises in the North Sea and took part in an Anglo-French amphibious training exercise—Corsican Lion—during 2012.