WASHINGTON — If the Air Force has to fight a major adversary such as China in years to come, a top general said, it must bring “mass” in its airpower — without breaking the bank. But piloted fighters alone won’t be enough to maintain the United States’ prized air superiority, Lt. Gen. Richard Moore , deputy chief of staff for plans and programs, said in an interview with Defense News. Key aircraft in its fleet such as the F-15C are rapidly aging, and the service is on track to retire more than