17(Reserve)squadron started operating from Edwards, with ZM135 (BK-1) commencing operations.
ZM137 (BK-3) is the aircraft currently assigned to VMFAT-501 at MCAS Beaufort, while ZM136 (BK-2) is still at Eglin AFB and remain there (see below).
https://www.f35.com/news/detail/17-rese ... 35-testing
17 (Reserve) Squadron has begun operational testing of the UK’s first F-35B, 100 years after the unit was first established.
The squadron, which was first formed in 1915, will be responsible for all the test and evaluation of the UK’s first F-35 Lightning II.
The aircraft, known as BK-1, is stationed at Edwards Air Force Base in California and will be operated under UK regulations. Personnel from 17 (R) Sqn, which is made up of engineers and pilots from the RAF and Royal Navy, will fly and maintain the jets independently from their US colleagues - an important step towards the UK developing its Joint Strike Fighter capability.
--------------------
With 17 (R) Squadron now stood up at Edwards AFB, the first operational aircraft for the UK (BK-3) has recently arrived at Marine Corps Air Station (MCAS) Beaufort in South Carolina. Aircraft BK-2 remains at Eglin AFB in Florida, where it forms part of the international training fleet. A third test aircraft, but the fourth to be ordered (BK-4), has been signed for and is due to be delivered in early 2016.
Once its role with 17 (R) Squadron is complete, BK-3 will join the first 14 operational aircraft which the government has approved (the first four of which have now been ordered) at MCAS Beaufort to form the first operational unit of 617 Squadron 'the Dambusters'.
In 2018, 617 Squadron will transfer to its future home station at RAF Marham in the United Kingdom, and in December of that year the UK will declare initial operating capability - land (IOC - Land) for its F-35B force.
The second unit - the FAA's 809 'Immortals' Naval Air Squadron - will be created ahead of the commencement of sea trials aboard the future HMS Queen Elizabeth aircraft carrier in 2018, with the full operating capability (land and maritime) being declared in 2023.
http://naval.dfns.net/2015/02/10/uk-sta ... ials-unit/