Timing of reference

[Topgun505]

When you are starting up, do you switch the rotary to NAV prior to taxi or wait until you are aligned on the runway? If it is after you get on the runway, do you hit your reference button (if needed) before or after that point?

[razo+r]

You can turn to NAV before taxi, but then you need to taxi fast to keep the NAV system running, otherwise it could die due to overheat. It's much better when you align on the runway, turn to the NAV mode and then press the reference button.

[2-niner]

I remember reading somewhere that you need to take off within 3 minutes of engaging NAV, so yeah I also engage it on the runway.