Engine ground testing for the F-35B Joint Strike Fighter began on April 18 with the F135 engine start at Palmdale California. The 19 System Development and Demonstration aircraft will be the test bed for the joint General Electric F135 and the Rolls-Royce F136 engine Teams. The F-35 Lightning II has already undergone high altitude afterburner testing, and this series of tests will examine the weight optimized F-35B CTOL and STOVL control technologies at its testing facility in Peebles, Ohio.