forward acting weight vector?
 

Came across this topic while briefing with a student today. Anybody know what it means?

I think I'd call it inertia. In what context was this?

I'm no physics guy (so I'm thinking back to high school), but seeing force is mass X acceleration, it makes some sense.

To be technical, weight has to do with gravity, so forward acting weight makes no sense to me.

I'm assuming this is stemming from a discussion about the 4 forces. We all remember that the sum of all forward forces equals the sum of all rearward forces. Due to gravity, weight plays a role in this equation when not in level flight. For example, in a descent, weight does not act parallel to the vertical axis, but rather slightly in front of it. This means that technically, part of the weight of the airplane is adding to the thrust component. The exact opposite is true in a climb, where weight adds to the drag component.

vector = magnitude + direction
weight vectors are present in precession. Weight vectors are almost always directly down (towards the force, gravity)
Forward acting weight vector is basically the other "engine" Wolfgang Langewiesche was talking about in "Stick and Rudder". It is actually better represented as angular momentum as it is a conserved value as a vector product.

thanks for the replies. I believe that it is related to glide performance as well as descents.