The most numerous aircraft in the US Army's fixed-wing aircraft fleet is the Hawker Beechcraft King Air which is used in over 165 aircraft over 13 different version from utility transport (such as the C-12 Huron) to special mission aircraft (like the RC-12 Guardrail). By mid-2009 the utilization of this diverse fleet of King Air variants had already reached approximately 173,000 flight hours.
Approximately 113 C-12s are in use operationally and fly an average of 48.2 hours monthly with an operational readiness rate of 91.1%. The more complex RC-12s fly 38.6 hours monthly and have an average readiness rate of 89.9%. Both fleets of aircraft have an average age just over 20 years old.
The Army's first King Air was delivered on 16 May 1967 in the form of the U-21A Ute that was an unpressurized hybrid of the Beech Queen Air fuselage with the wings and tail of the newer King Air 90 series. The newer C-12A based on the Super King Air 200 was first deployed by the Army in July 1975. The newest Army King Airs are modified C-12C/D/V aircraft for Task Force ODIN (TF ODIN- Observe, Detect, Identify, and Neutralize) created at Fort Hood, Texas in August 2006 to conduct airborne intelligence and surveillance in support of anti-IED efforts in Iraq. The TF ODIN aircraft have an underfuselage Lynx hi-resolution SAR, EO/IR sensor turrets and other communications/sensor equipment to assist in the counter-insurgency efforts.
Source: Air Forces Monthly, November 2009. "US Army King Airs" by Tom Kaminski, p84-89.
