With the F-16C/D Fighting Falcons, KC-135R Stratotankers, AH-64D Apaches and CH-47SD Chinook helicopters based in the United States, the Marchetti S-211s, PC-21s, and Super Puma helicopters in Australia, and the Alenia Aermacchi M-346 Master in France, almost one third of the force's inventory is based outside Singapore.