22.30 Range and Endurance

22.30.2 Define specific air range (SAR) and specific fuel consumption (SFC).

Specific air range (SAR) is the ratio of distance covered for the fuel consumed

– air nautical miles per pound of fuel

– a form of efficiency.

Specific air range (SAR) precisely measures the distance an aircraft can travel through still air for a given amount of fuel consumed.

Specific range refers to the distance an aircraft can travel per unit of fuel burned.

There are two ways to express specific range:

Specific Air Range (SAR):

• air nautical miles per unit of fuel, and

Specific Ground Range (SGR):

• ground nautical miles per unit of fuel.

SAR focuses on the distance traveled through the air, while SGR considers the actual distance covered over the ground.

22.30.4 State the general conditions for achieving maximum SAR.

Maximum range occurs when there is the best ratio of distance over fuel – or TAS over fuel flow,

when it comes to maximizing the range of an aircraft, the key factor is making the most out of the finite fuel available.

To achieve the best specific air range (SAR), we need to aim for the optimal ratio of True Airspeed (TAS) to fuel flow.