In November 2016 the USAF Scientific Advisory Board announced studies for a Penetrating Counter Air (PCA) platform that would combine long range, supersonic speed, stealth and maneuverability and be fielded by 2030.[49] PCA would have substantially longer range to fly long distances over the Pacific, especially in a situation where airbases in the vicinity of China are not available[50] or if aerial tankers are destroyed.[51] It would also escort bombers deep into Russia or China, where the anticipated threat includes advanced networked air defense radars. It would include stealth against low or very high frequency radars (like those of the S-400 missile system),[52] which requires an airframe with no vertical stabilizers. Another requirement is significantly larger payload than current air superiority aircraft like the F-22.