One could reasonably wonder why if the AV-8B and MV-22 had known issues with thermal stress on deck (and under deck) structures, why did the America Class require such an extensive redesign (and yard period) to accommodate the F-35B? It cost hundreds of millions of dollars to modify and refit the LHA-6 and the USS Wasp, and millions more will be spent modify the follow-on LHA-7, and refit other amphibs (LHA-8 will have the mods incorporated into its build.) These are not limited to mechanical structures: electrical systems, mx departments, space for ALIS, etc. - all need modification. I think it's reasonable to assume that A wasn't talking to B, and the thermal and mechanical loads that the F-35B imparts on underlying structures is much greater than anticipated.