Radius of action, combat radius, or combat range in military terms, refers to the maximum distance a ship, aircraft, or vehicle can travel away from its base along a given course with normal load and return without refueling, allowing for all safety and operating factors. A given aircraft's

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

of action varies according to the

altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

of its flight plan, amount of weight ( ordnance in a military context) it is carrying, and whether or not it carries external drop tanks full of fuel. *An aircraft engaged in '' low-level (lo)'' flight will have a smaller radius of action than the same one engaged in a ''high-level (hi)'' mission, due to higher fuel consumption at lower altitudes (higher

atmospheric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibar ...

/ air density). *An aircraft with more and heavier load (''ordnance'' in military terms) will have a smaller radius of action (''combat radius'' in military terms) than the same one with less and lighter load, due to higher fuel consumption at heavier weights. *An aircraft with

drop tank In aviation, a drop tank (external tank, wing tank or belly tank) is used to describe auxiliary fuel tanks externally carried by aircraft. A drop tank is expendable and often capable of being jettisoned. External tanks are commonplace on modern ...

s will have a greater radius of action than the same one without. In military aviation, the combat radius of an aircraft is often given with its mission profile (without in-air refueling). For example: *The

F-16 Fighting Falcon The General Dynamics F-16 Fighting Falcon is a single-engine multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superiority day fighter, it evolved into a successful ...

's combat radius is 550 km (340 mi) on a ''hi-lo-hi'' mission with six 450 kg (1,000 lb) bombs. *The F/A-18 Hornet has a combat radius of 537 km (330 mi) on a ''hi-lo-lo-hi'' mission. The radius of action of an aircraft is always smaller than its maximum range (a. k. a. combat range), the furthest distance the aircraft can fly with maximum payload and without refueling, or ferry range, the furthest distance the aircraft can fly with drop tanks, no load or ordnance and without refueling. The rule of thumb is that the radius of action is one-third the distance an aircraft can fly in a straight line on a full load of fuel. In military aviation, this assumes a trip out and back, plus one-third of fuel for combat operations.

References

Military aviation {{Mil-aviation-stub

See also

References