Why does an offset of a steerpoint affect all waypoints?

[d0ppler]

Yes, I know, CZ will fix it, but I still can't understand why it has to affect every steerpoint loaded into my system when I slew my cursor off from the PRE point. Can someone explain the reason behind this?

Edited February 27 by d0ppler

[Furiz]

@d0ppler

Cause the sensor point of interest at CZ is at the steerpoint, you don't move the steerpoint (you notice that when you press CZ your SPI is then moved back to STPT) but you move the SPI and the aircraft does that by creating an offset from currently selected STPT. So when you change STPT without performing cursor zero, thus zeroing the offset, next STPT will show with that offset applied as well.

It doesn't show it to you visually but that's what happens. You can check that by pressing 4 on the ICP, you will get STPT info showing coordinates and then move your TGP around you will notice that those coordinates don't change, that's cause STPT is not being moved, SPI is moving.

Edited March 1 by Furiz

[Tenkom]

On 2/27/2025 at 2:21 AM, d0ppler said:

Yes, I know, CZ will fix it, but I still can't understand why it has to affect every steerpoint loaded into my system when I slew my cursor off from the PRE point. Can someone explain the reason behind this?

The reasoning behind it, as I've understood it, is correcting for INS drift. If you have several pre planned target waypoints you will only have to adjust one of them in the case that they have drifted off.