In Aviation what is H arm means in load and trim preparation for a particular flight ?

Question

In Aviation what is H arm means in load and trim preparation for a particular flight ?

Answer 1

i have never heard of that...

Answer 2

I'm not sure about the H part, but the arm is a measure of the distance between the load and a certain reference point established by the manufacturer.  The further a load is from this point, the greater the influence it has on balance and trim.  For many small aircraft, the reference point is just at the front of the aircraft, but in some cases it is somewhere within the aircraft—it's all a matter of the manufacturer's preference.

Typically you look at the various things you're putting in the aircraft and their distance from the reference (datum) point, which is the "arm," and you multiply the weight by the arm.  Ultimately you come up with a figure for the center of gravity for your load, and it must be within a certain range of the reference point based on the manufacturer's recommendations.  If it's out of range, you risk not being able to control the aircraft properly after leaving the ground.