https://thedefensepost.com/2018/10/2...ters-approved/
“In December 2015, Boeing
delivered the 14th Mk6 Chinook to the U.K. Royal Air Force, growing its fleet to 60 aircraft. The RAF’s current operational fleet
includes the Mk6 and Mk4 aircraft. The Mk3 “fat tank” extended-range helicopters have been upgraded to a glass cockpit configuration designed Mk5.
The RAF’s Mk4 aircraft are due to undergo modifications to incorporate the Digital Automatic Flight Control System seen on the Mk6 variant. They will be designated Mk6A and are expended to extend the U.K.’s Chinook capability to 2040......
The RAF is due to retire its Puma medium lift helicopters in March 2025.”