Question

Which of the following is the correct formula for specific air range?

(a) SAR=\(\frac{\eta}{C}\frac{L}{D}\frac{1}{W}\)

(b) SAR=\(\frac{1}{PC}\)

(c) SAR=\(\frac{\eta W}{C}\frac{L}{D}\)

(d) SAR=\(\frac{1}{C}\frac{L}{D}\frac{1}{W}\)

The question was posed to me by my school principal while I was bunking the class.

I need to ask this question from Range and Endurance for Aircraft with Power Producing Engines in division Cruising Performance of Aircraft Performance

Answer 1

Correct answer is (a) SAR=\(\frac{\eta}{C}\frac{L}{D}\frac{1}{W}\)

The best explanation: The correct formula for specific air range is given by SAR=\(\frac{\eta}{C}\frac{L}{D}\frac{1}{W}\) where η is propeller efficiency, C is specific fuel consumption, L is lift, D is drag, W is weight. SAR can also be written as SAR=\(\frac{V}{CP}\) where v is velocity, C is specific fuel consumption and P is power.