# Find the gliding distance of an aircraft.

Find the gliding distance of an aircraft flying at an altitude of $$1500\,m$$ with a maximum lift to drag ratio of $$8$$.

Asked on 3rd February 2021 in

Aircraft starts to glide at an altitude of $$1500\,m$$.

From the figure,

Aircraft in glide

$\tan \theta = \frac{h}{D} \Rightarrow D = \frac{h}{{\tan \theta }}$

Forces in gliding aircraft

For the unaccelerated glide, in equilibrium $$L = W\cos \theta$$, $$D = W\sin \theta$$,

$\Rightarrow \left( {\frac{L}{D}} \right) = \frac{{W\cos \theta }}{{W\sin \theta }} = \left( {\frac{1}{{\tan \theta }}} \right)$

On putting the values , to calculate the distance

$D = \frac{h}{{\tan \theta }} = h\left( {\frac{L}{D}} \right) = 1500 \times 8 = 12000\,m$