Question

A prop driven aircraft has propeller efficiency of 0.92 and C as 0.000745 1/m. If lift to drag ratio is 14 and weight fraction as 1.145 then, find range of the propeller driven aircraft.

(a) 2340.95m

(b) 2340.5miles

(c) 2340km

(d) 2500miles

I have been asked this question by my college professor while I was bunking the class.

The query is from Flight Mechanics topic in section Performance and Flight Mechanics of Aircraft Design

Answer 1

Right answer is (a) 2340.95m

To elaborate: Prop range = (lift to drag)*[propeller efficiency/C]*ln (weight fraction)

= 14*[0.92/0.000745]*ln (1.145) = 2340.95m.