Senior British military officials confirmed that the UK will conduct shipboard rolling vertical landing (SRVL) trials on the F-35B version of the Lockheed Martin Lightning II stealth combat jet. The SRVL technique would allow the aircraft to land at higher weights than is currently possible in the VTOL mode. The F-35B has faced weight problems, leading to concerns that it could not “bring back” to its aircraft carrier a useful weapons load that has not been expended in combat. The British have done nearly all the previous research and simulation on SRVLs.

The officials said they are satisfied that the F-35B could bring back the internal weapons load that is initially planned, comprising–in the UK case–two AMRAAM air-air missiles and two Paveway IV smart bombs weighing some 5,000 pounds. But, one added, when high temperature and/or low pressure conditions prevail–such as in the Gulf of Oman–it would be prudent to achieve another 2,000 to 4,000 pounds of bring-back weight, for either fuel or weapons, especially since the F-35 will be able to carry additional weapons on wing pylons, when stealth is not a requirement.

The UK will formally decide later this year on a further purchase of F-35s, beyond the three already acquired (at a cost of $350 million) for test and evaluation (T&E). The number under consideration is believed to be 15, enough to equip an initial operational squadron. Another 30 are likely to be approved before 2015, when another British defense review will consider how many more F-35s the country can afford. Until then, the officials maintained, the UK “program of record” remains a total of 138 F-35s. Most observers believe that the UK will not acquire more than 100 F-35s, and some suggest the final total might be as low as 70.

The officials revealed that the UK will work closely with the U.S. Marine Corps to bring its F-35Bs into operational service. After it is formed in 2016, the first British squadron will be based at MCAS Yuma and integrated with the co-located USMC F-35B fleet. Pilots of both services will be able to fly the others’ aircraft. The squadron will relocate to RAF Marham in the UK in early 2018 and be ready for combat from land bases by the end of that year.

Meanwhile, the UK’s three T&E jets will embark on the new Queen Elizabeth II aircraft carrier for trials in the same year.