Dopey question - autopilot problem

[johnpc 0]

I'm embarrassed to have to ask such a dopey question after using PMDG products from Day One, but I've just moved my Windows 7, FSX-installed PC to a new room and today I couldn't get the autopilot to engage. Scenario: Normal start from cold and dark, take off, both LNAV and VNAV panel lights are green, autopilot engage bar up, but no response from autopilot system, aircraft just continues in straight line.I've racked my brains, tried all sorts of fixes, confirmed autopilot is working in default FSX aircraft, etc. Help for old but not so wise flyer please?

[johnpc 0]

Also, I've just done a complete un-install and re-install of the base PMDG 747X package and the liveries, same outcome. Driving me insane. Any ideas before I try a complete FSX un-install and re-install?

[sheepfu 3]

Are you remembering to select an Autopilot channel with the CMD buttons?

[johnpc 0]

Oh boy...it was a dopey question. That was exactly what I was missing! It only goes to show that even experienced flyers don't know everything. Thanks very much sheepfu!

[sheepfu 3]

In case it makes you feel better, I did this with the NGX last night. Saying to myself why the F&^$ won't it climb in FLCH mode!!!

[engwerda 0]

johnpc, Not dopey at all. I bet there were at least a dozen others checking out this post wondering what the answer was as well. Gerry

[Porthos 9]

there is no such thing as a dopey or dumb question one little comforting thought I live with is that all experts were once beginners.

[mtabb 0]

I have a question similar to the one above. I fly the PMDG MD11 and the 747-400. Lately, I've had a hard time getting the LNAV to engage and track the next waypoint. is my problem similar to the one described above. I'm not sure what it means selecting an autopilot channel with the CMD button. If the disengage bar is up and a CMD button is selected, how can the LNAV button not engage?

[Allan Burek 3]

Mike, If you are at a discontinuity in the FMC, then LNAV wont engage. Check to make sure that your FMC is pointing to an actual waypoint.

[pdogone 0]

Phil strattonnew to the pmdg 747 also.. after much reading and trial and error i finally got the fmc/cdu to work...(yay) now i get to takeoff and engage the toga lnav vana auto thr and fd plus one cmd auto pilot..climbout not bad (hit 260 knts under 10,000) plane flew nicely and leveled out at 9000 per atc..got on my track north past boston and then noticed my lnav when out..allan sounds like you are familiar with this..i check my fmc and there was a msg about not on course for waypoint? tks for any help keep em flying

[dmm200 0]

pdogone it's probably telling you "not on intercept heading", which gives you two options:-turn your plane towards the active waypoint and once you're facing it hit LNAV againor-click the first available fix twice (as in select it or type it and then click the same fix at the top) which will create a little LNAV path for your plane to follow to the active waypoint

[pdogone 0]

phil strattonthanks dmm200 ill give that a try and yes it should have read not on intercept heading thanks again

[pdogone 0]

phil strattondmm200 that worked lnav engages..what happens now is atc wants to direct me and its not the same route..is that fsx doing that or do i just ignore atc? any help appreciated. i loadeda british airways flight and switchedthe aircraft to pmdg 747.

[Chas1 0]

pdogoneI have had this problem many times in FS2004 and what I do is fly past the first waypoint on the correct heading of the next waypoint and then select LNAV and that works.In regards to the atc question I acknowledge what they say and keep flying towards the waypoint. They keep telling me to turn but I just ignore it and then when you reach the waypoint and get back on track they kinda catch up with you and tell you turn on course and everything is ok.I don't know if it's the same in FSX though but I hope it helps

[scandinavian13 5,192]

..climbout not bad (hit 260 knts under 10,000)

260 under 10,000 isn't against the regs, if that's what you're implying:

Sec. 91.117 — Aircraft speed.(a) Unless otherwise authorized by the Administrator [see below], no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).[...](d) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

Emphasis and annotation mine.