Was in ALC yesterday, heard all (UK) carriers following the arc on a beacon that was coding wrong. The ALT VOR/DME was coding TLT (no, not TST (test)). So what is safe?
I know that most of us are flying that arc in LNAV until intercept so it is flown on FMC database figures but I heard nobody reporting it! And the mayority of airliners have got GPS nowadays.
My point: even if you fly that magenta line (which feels safe), don't throw your airmanship away and keep safe!