By 
Engine maker Rolls-Royce has finished about 90 percent of the work necessary for the Marine Corps to declare the F-35B battle ready on July 1, according to Vice President of Customer Business Tom Hartmann.The company provides the lift fan, directional bearing swivel module and roll posts for the short-takeoff, vertical landing variant of the F-35. It also builds the crank shaft that connects the lift fan to the main Pratt & Whitney [UTX] F135 engine that powers all three variants…
