Question

What is the value of specific fuel consumption where the fuel heating is 42,800kJ/kg and power produced is 5760 kW-hr?

(a) 0.135 kg/kW-hr

(b) 7.43 kg/W-hr

(c) 1.546 kg/kW-hr

(d) 7.43 kg/kW-hr

The question was asked at a job interview.

Origin of the question is Range and Endurance for Aircraft with Power Producing Engines topic in chapter Cruising Performance of Aircraft Performance

Answer 1

The correct option is (d) 7.43 kg/kW-hr

Best explanation: The answer is 7.43 kg/kW-hr. Given Qf=42,800 kJ/kg and P=5760 kW-hr. From the formula C=\(\frac{Q_f}{P}\) we will find C. On substituting we get C=\(\frac{42800}{5760}\).

On solving above equation we get the value of C=7.43 kg/kW-hr.