Nav failes

[Jetstream41 0]

Hi my name is Emil Nilsson.When i first start up the plane from cold and dark it says on the speed indicator "NO TAXI". And when i take off NAV stoppes working it just says for example "HEADING 150" and it isent even heading 150. Why is this happening please help me!

[james008 5]

Hi,(the first question: "no taxi" indication on the PFD)This indication remains on the PFD while the IRS is off, or while the IRS is on, but not completely alligned, indicating that you must not move the airplane. When the allingment is complete, the indication changes to "taxi", meaning that you can now move the aircraft.(the second question: "nav" mode going off after take-off)I think I did not understand your explanation, but I will suggest you to verify if your flight route is correctly programmed on the FMS, and if it is correctly drawn on the ND, providing to the aircraft a continuos route, without discontinuitys. And, of course, if you are trying to take-off without allign the IRS units, you will never use NAV mode.Regards,Marcelo Monteiro