The Bell OH-58D Kiowa was developed from the earlier OH-58A as a part of the U.S. Army’s Helicopter Improvement Program in the early 1980s. The helicopter incorporated a more powerful engine and transmission as well as a four-bladed rotor which decreased the aircraft’s noise level while improving low level performance. The distinctive Mast Mounted Sight above the main rotor allowed the helicopter to scout for targets without rising above trees or hills. In the late 1980s improvements to the helicopter’s armament systems allowed the Kiowa to carry hellfire anti-tank missiles, unguided rockets, and .50 caliber machine guns. This armed version was called the Kiowa Warrior. The Army deployed Kiowa Warriors extensively in both Iraq and Afghanistan. At least 35 were lost in combat. The OH-58D was retired from Army service in 2016.
Diameter of Main Rotor
United States Army, 6th Squadron, 6th Cavalry Regiment, 10th Combat Aviation Brigade, Fort Drum, New York, 2015
Pima Air & Space Museum