WASHINGTON (Reuters) - The U.S. Air Force contract to start replacing the aging fleet of JSTARS spy and battle management planes is expected to be awarded in the first quarter of fiscal 2018, Air Force Secretary Deborah James said on Wednesday. James told a U.S. House of Representatives Armed Services Committee hearing it was regrettable it was taking longer than expected to award the engineering, manufacturing and development contract. Last year the Pentagon’s chief arms buyer approved the next step in a multibillion-dollar competition to replace 16 Joint Surveillance Target Attack Radar System aircraft, or JSTARS, which have flown over 100,000 combat hours and are approaching the end of their service life. 