 Grumman was selected for the contract award in January 1969.Grumman's design reused the TF30 engines from the F-111B, though the Navy planned on replacing them with the Pratt & Whitney F401-400 engines under development for the Navy, along with the related Pratt & Whitney F100 for the USAF.Though lighter than the F-111B, it was still the largest and heaviest U.S. fighter to fly from an aircraft carrier, a consequence of the requirement to carry the large AWG-9 radar and AIM-54 Phoenix missiles (from the F-111B) and an internal fuel load of .