US Air Force is the largest air force in the world
US Navy/Marines is the second largest air force in the world
http://nationalinterest.org/feature/top-guns-the-most-lethal-air-forces-the-planet-11814
The U.S. Navy and Marine Corps
Worthy of separate mention due to their size and capabilities, the U.S. Navy and Marine Corps are combined the world’s second-largest air force, with a total of over 3,700 aircraft of all types. This includes 1,159 fighters, 133 attack aircraft, 172 patrol aircraft, 247 transports and 1,231 helicopters.
The aircraft of the U.S. Navy are responsible for protecting the U.S. fleet and conducting air missions from and often over the world’s oceans and seas. Most of the aircraft of the Navy and Marine Corps operate from ships at sea, a difficult and dangerous job that requires a high level of training and proficiency.
Ooohrah baby.