The Lightning Force is not deploying in its entirety - as that would cause problems with training and growing the force. The same also applies for other elements such as the Merlin. We should remember that this is not an all out response to a crisis. HMS
Prince of Wales will be doing trials and training soon and will need some cabs. There are other operational activities too - like NATO activities such as BALTOPS and in the Atlantic and Arctic.
According to this
description of the deployment:
The Carrier Strike Group will participate in NATO exercises such as Exercise Steadfast Defender, and provide support to NATO Operation Sea Guardian and security operations in the Black Sea.
In total, units from the group visit more than 40 countries and undertake in excess of 70 engagements, visits, air exercises and operations.
Also on Euro Atlantic security:
Merlin helicopters arrive on HMS Queen Elizabeth...
In all, seven Merlin helicopters (three with Crowsnest and four for anti-submarine warfare) from Royal Naval Air Station Culdrose in Cornwall will join the carrier and will be the airborne guardians of the strike group.
Between them, they will defend the carrier and her escorts from threats below the waves, on the surface and in the air.
I was initially a tiny bit confused by the wording, as Crowsnest is supposed to be a role fit that is fitted to the HM2 as and when. If the Crowsnest kit is removed and the ASW gear put back, the aircraft goers back to being a Pinger. I am not sure if one of the frigates is going to carry a Merlin, but I do recall that d
uring WESTLANT 19 three Merlin HM2s aboard Queen Elizabeth and a Type 23 with towed array sonar and a Merlin were able to provide continuous ASW cover for the carrier and her small group, but covering a larger area demands more frigates and more Pingers. It does reinforce the case for 820 NAS taking nine Merlin HM2s to sea, so if three are doing the ASaCs role, there are six dedicated to ASW, with Jungly Merlin HC4s relieving them of things such as SAR and utility roles. Six dedicated ASW cabs with dipping sonar etc, plus another one or two flying from frigates.
They did manage to put nine aboard HMS Illustrious for Exercise Deep Blue in June/July 2014, with another on the accompanying frigate.
With the utility and SAR taskings being picked up largely by Jungly HC4s, six aircraft with a five hour endurance can probably achieve the same level of ASW coverage as a squadron of nine aircraft with a four hour endurance (the old Sea King), with those nine also having to perform utility roles as often keeping a helicopter on standby for SAR.