# How to determine the maximum servo torque required for a nose gear?

It's pretty much it. I know how to calculate the friction force on the nose gear for a three-point landing condition using the method set forth in Structural Loads Analysis for Commercial Transport Aircraft Theory and Practice, by Lomax. To calculate the torque I am looking for, would I just take the cross product between the friction and the radius of the nose gear?

Assuming that we are designing a steering system, for a single steering wheel aircraft.

The servo is yawing the wheel to a position. The position causes side force on the wheel. And that generates a yawing moment for the aircraft. (The aircraft can be moving in various directions, but assume you know the max side force required.)

This side force, multiplied with the distance of the wheel contact point and the wheel yawing axis is one major contributor to the servo torque. (Torque1)

Another contributor is the rotational friction of the wheel. Which is the resistance to yawing further. (Torque2)

Torque_total = torque1 + torque2.

This is the output torque for the servo mechanism. The mechanism will affect the torque on the servo shaft.

• Can you further explain the Torque 1, please? – Unicorn Lord Jul 25 '18 at 22:38
• I’ve come across this image that depicts the landing gear: goo.gl/images/Mvyu7T – Gürkan Çetin Jul 26 '18 at 14:54