After update to V1R10, I found the A/T ARM doesn't work. Before that, when I ON the A/T. I can see THR REF on PFD.Now I must press VNAV twice then I can see THR REF.

When arming the A/T in a B744, you don't have any indication in the PFD. (spd mode is empty)Normally before t/o, after arming A/T you only have TOGA pitch and TOGA roll modes in green in your PFD with LNAV/VNAV under it in white when they are armed before your take off and F/D is on.Only the switch position on the MCP gives you an indication that A/T is armed. (This is different in a B737 where you have a white ARM indication when the A/T is armed)B. rgdsMichel

When I turn the A/T ARM switch ON? Before t/o or after t/o?In "PMDG 747-400 Operating Manuals" I can't clearly find when.So, I leave A/T ARM OFF untill I t/o. But after t/o and climbing I turn on the A/T ARM, the A/T mode doesn't work. In FMC "250/10000" was set. but the airspeed is out of control. PFD is still blank about the throttle reference. When this situation, I must slow down manualy. Or I press VNAV button twice whatever VNAV is ARMed or not.BUT before V1R10. I never reach this problem. Still leave A/T ARM OFF, push throttle, speed up, t/o, climbing, then A/T switch ON. everything is OK.

Billy (I guess that's your name?),I think that the best you can do is sit down and read this post:http://forums.avsim.net/dcboard.php?az=sho..._id=95618&page=It explains everything you'd want to know about the proper use of A/T.Hope this helps,S

According the standard SOP's , A/T switch is set to arm normally, just prior to line up. F/D switch set to on during prefight. LNAV, VNAV may be armed as well before engines start.B. rgdsMichel

"A/T switch is set to arm normally, just prior to line up."Actually, you'll find that a lot of airlines leave it armed all the time... and if they find it not armed during preflights, they will switch in on when they set up their MCP at the gate.However, it makes sense to arm it just prior to turning onto the runway (for safety reasons).... although the TOGA switches are not so easy to accidentally bump.Cheers.Q>