Confused by sentense in checklist.

Good day. In the manual, page 239 is written:

Master Mode selector: NAV (At the earliest 2 minutes before throttle up, to avoid problems with the navigation system)

I don't understand this sentense. Does it mean:

1) I have to turn on NAV mode at least 2 minutes before take off?

2) I have to take off in 2 minutes after the turning on the NAV mode?

Thank you for answer.

You have to take off or throttle up within 2 minutes AFTER you turned it to NAV mode. Best thing to do is just wait until you are ready to take off and then put it in NAV mode to make sure you don't go above 2 minutes.

It's 2). You shouldn't have NAV turned on longer than 2 minutes on the ground.

Usually people turn it on when they are at short-stop or elsewhere right before take off.

oh my, i always did it wrong! :O

i switched it on either mid-air or right after arming the plane ...

Like someone said above, best rule of thumb is to switch it on as you move onto the runway for takeoff. The chances of you aborting at that point are less than 1% in the game.

Thank you all for answer.