Hello there

Here's is a path vector used in most aircraft. It shows where the aircraft is going by looking at the angle of attack and angle of slip.

How it works?

Attach it to your plane by the hinge that is connected to the cockpit, do whatever you must to accomplish that if you attach it by somewhere else it won't move.

The connection hinge is responsible for the vertical movement of the path vector, it uses the following formula:

TAS > 15 ? clamp(AngleOfAttack/90,-0.3,0.1) : 0

As you can see it won't activate unless true airspeed is more than 15 m/s. This is because when stationary the angle of attack and angle of slip value goes from 180 to -180 and bounces all over the place making the path vector jump all over the place. Also I used the clamp function to limit the movement such that it won't be outside the HUD.

The second hinge is responsible for the angle of slip, uses a very similar formula:

TAS > 15 ? clamp(AngleOfSlip/90,-0.07,0.07) : 0

Important thing to note is that if you have a very low drag count plane and you set a high windspeed then the path vector will be wrong (as far as side movement is concerned) as it shows the angle of slip faced by the cockpit itself, not exactly where the cockpit is going. I have a fix in mind for that but I don't think it will cause a major headache for anybody so I decided to share this anyways.

Finally, it is especially useful for carrier landings but you probably recognized that from the thumbnail. Have fun!

EDIT: Forgot to mention this but it is important, make sure the hinge coordinates are on the cockpit, otherwise you will have an degree offset error. You can move the symbology in the 'z' direction according to your needs.