Calculate the Specific Air Range for TAS 360 kts and fuel burn 3000 kg/hr.

• A. 120 nm/tonne
• B. 100 nm/tonne
• C. 90 nm/tonne
• D. 150 nm/tonne

Answer: (A)

Specific Air Range measures how far you can fly for each unit of fuel consumed, usually expressed as nautical miles per tonne of fuel. To compute it, use the distance flown in one hour and divide by the fuel burned in that same hour, making sure the fuel is in tonnes.

Here, you travel 360 nautical miles in one hour at the given true airspeed. The fuel burn is 3000 kg per hour, which is 3 tonnes per hour. So the distance per tonne of fuel is 360 nm per hour divided by 3 tonnes per hour = 120 nm per tonne.

So the SAR is 120 nautical miles per tonne of fuel. This result comes from converting fuel burn to tonnes per hour so the units cancel properly and you’re expressing distance per unit of fuel.