The Pentagon's plans to fund 50 percent more F-35 fighter jets in fiscal 2016 will help drive down the price of the new plane and its engine, a top official with enginemaker Pratt & Whitney, a unit of United Technologies Corp , said Thursday. Bennett Croswell, president of Pratt's military engines division, said the company had submitted a proposal for the ninth and tenth batches of engines to the F-35 program office, and he hoped to sign those agreements by the end of 2015.