I have two flight plans (EHAM-KSEA, EHAM-CYVR) for the MD-11 that go north of 73 degrees latitude. Whenever I do these flights the HDG MAG automatically switchs to HDG TRU on the PFD around 73 degrees north and remains there for duration of the flight. Leaving it on HDG TRU has never caused any problems that I know of. Does it need to be changed to HDG MAG once south of 73 degrees north? I can find info about it in the Systems Manual except about wither switch it back.

 

Thank you

Michael Cubine

Michael,

 

the ultimate need to switch back to magnetic would be as soon as you get radar vectors by ATC. They are always magnetic, never true.

 

Cheers,

Markus

Markus,

 

Thanks for the info.

 

Michael Cubine