Question

A taxiway designed for subsonic aircraft has the following characteristics :

(i) Wheel base = 16 m

(ii) Tread of main landing gear= 6.5

(iii) Turning speed = 45 kmph

(iv) Coefficient of friction between tyre and pavement = 0.15

The absolute minimum turning radius will be _______ m.

• A. 120

Answer 1

The correct option is A 120
(i)Turning radius, R = $\frac{V^2}{125f}=\frac{{45}^2}{125\times 0.15}=108m$

(ii) From Horonjeff's equation, R = $\frac{0.388W^2}{\frac{T}{2}-S}$

Here, W = 16 m

T = 22.5 m

$S=6+\frac{6.5}{2}=9.25m$

$\therefore R=\frac{0.388\times {16}^2}{\frac{22.5}{2}-9.25}=49.644m$

(iii) Absolute minimum turning radius for subsonic aircraft regardless of any speed = 120 m. Selecting maximum among three cases discussed above, so turning radius = 120 m