Dopey question - autopilot problem

[pdogone 0]

phil strattontks just get that msg from the sim max speed under 10000 is 250 ...phil strattonchas1 tks for the tip ill try that and see if lnav engages...its probably a limitation of fsx atc not really knowing the flight plan i use from pmdg 747...be cool if in future you can file a plan and the sim recognises it... thanks again to all who responded.

[pdogone 0]

phil strattondoes anyone know why pmdg just uses three letter designations for airports and not the usual four? some are obvious but others are not and it is a little tedious having to look them up. ie heathrow is egll but pmdg routes it as lhr,,,so when you plan a coroute which is correct: lrhjfk001 or should i use egllkjfk001...finding that some seem to work and others are not in databasetks for any help clearing it up for me..

[MrKen 3]

They use whatever nav data is loaded into fsx. I've never run across any airports that didn't use the full icao.