how does this work? thanks in advance.

Quite well, actually

so you may choose any bearing or speed?

Both cards have the same timing: when you reveal your maneuver. Both cards let you rotate your dial to a different maneuver. Navigator lets you choose a maneuver with a different speed but the same bearing (the maneuver's symbol, e.g. "straight", " left turn", "right bank"), with the caveat that you can't choose a new maneuver that is red if you are stressed. Stay on Target lets you choose a maneuver with a different bearing but the same speed, with the caveat that the new maneuver will always be treated as a red maneuver.

Since the timing window is the same, you can choose the order in which you activate them. So if you reveal a 1 left bank, you could use Navigator to turn that into a two left bank (same bearing, different speed), then use Stay on Target to rotate again to a 2 right turn (same speed, different bearing), which would be treated as red. Or you could use get the same result by using Stay on Target first to change your 1 left bank into a 1 right turn, then Navigator to turn your 1 right turn into a 2 right turn. (But only if your dial has a 1 right turn!)

The FAQ entry for Stay on Target clarifies that if you use Stay on Target your maneuver will stay red even if you use Navigator (or something else) to later change it to something that isn't normally red. So if you have both cards and you're stressed, you can't use Navigator after Stay on Target (using Stay in Target at all while stressed is a one way ticket to hand-over-your-dialsville, so don't do that unless you've got some Thrawn-level mind games going).

With both of these cards you can usually get from any maneuver on your dial to any other, at the cost of making it red, but keep in mind the fact that the intermediate step has to be on your dial.

With the two upgrades, both trigger at the same time, and having triggered, both will resolve.

Thus, you may alter in either order.

In fact, lets examine the Bomber dial as a case-study (Knowing, of course, that it cannot carry Navigator. This is mostly an academic explanation).

Let's say that you revealed a 1 Bank to the Right, which is White.

There is one maneuver and one maneuver only which the two upgrades in question would not let you perform: the 5 Koiogran.

Every other maneuver on the dial has a secondary location of intersection, either on the Speed or Bearing planes.

Going to a 3 Turn to the Left, you would Navigate to a 3 Bank to the Right, then Stay on Target to the preferred maneuver

Going to a 4 Forward, you would Stay on Target to a 1 Forward, then Navigate to the preferred maneuver.

Notably, if you use Stay on Target at any point in this process, you will treat your maneuver for the round as Red, irrespective of its color on the dial.

Some pilot abilities approximate one of the two upgrades.

• Imperial Boba Fett + Navigator allows one chosen bank to be treated as any of the 6 on his dial.
• Juno Eclipse + Stay on Target lets her change speed, then alter bearing, or vice versa. She can use maneuvers not on her dial this way, but only at +1 or -1 speed from the chosen maneuver.
• Tetran Cowall + Stay on Target lets him reveal a Koiogran, and perform any 1,3, or 5 speed maneuver on his dial (in Red)

In fact, lets examine the Bomber dial as a case-study (Knowing, of course, that it cannot carry Navigator. This is mostly an academic explanation).

Let's say that you revealed a 1 Bank to the Right, which is White.

There is one maneuver and one maneuver only which the two upgrades in question would not let you perform: the 5 Koiogran.

Heh. I was just going looking for an example of a maneuver you can't reach with both of them.

An example that could actually happen: a YV-666* with Navigator and Stay on Target can't change its maneuver to a 0 Stop if it reveals something else, nor change it to something else if it reveals a 0 Stop. Can't Navigator to/from the 0 Stop because there aren't any other Stop maneuvers, can't Stay on Target to/from the 0 Stop because there aren't any other 0 speed maneuvers.

*: Might as well just say "Bossk", because he's the only one with the Elite slot.