Does anyone know why my 727 nose dives hard when I activate the autopilot? That doesn't seem like a useful feature.

I'm flying the 200F

mine -100 flies straight. as shown in manual - you turn it on in MAN mode, and then you can switch it to other modes.  if i turn it on in MAN mode it'll level wings, and will maintain current attitude. maube you engaging AP with nose-down?? then it'll hold that pitch and you'll go down.

also look at the gps panel. check that avionics is on then you engaging autopilot.

Have a nice flying )

I'm engaging my autopilot on departure climb in MAN mode. It should hold my climb pitch and keep my wings level, but instead, it transitions into a severe nose dive and I have to take over.

What am I looking for on the GPS panel? What do you mean by avionics being on?

You doing all right.
about avionics - there is a kinda trick with this aircraft. avionics can shut-down inflight. That'll cause AP to fail.

check this topics on this forum -
http://www.captainsim.org/yabb2/YaBB.pl?num=1315183931 - there is a links inside.

avionics easy to check - just look at GPS, if its dead - then thats your story up in the link. if avionics on - i dont know then :) gotta think more on possible cause of that strange AP-piloting.

keep it up! thats an old bird. something needs to be fixed :)))
dont miss pressuration system fix from member Dutch. He's kool in fixing stuff :) its on this forum also.

The following is from the Support KB #4897:

Q: I have issues with autopilot pitch control.

A: We are aware of the issue, it appears only on systems with no MS Acceleration installed. Because Microsoft missed the AP PITCH HOLD token in FSX SP2, but our A/P requires it.



Fix for those who do not have MS Acceleration installed:
1. Please download the file.
2. Move the file to [Microsoft Flight Simulator X Root Folder]\SimObjects\Airplanes\CS_B727-100\panel folder. Press 'Yes' when asked to replace the file.

From: 727 Captain (FSX) / On the list for next SP (QID 4897)

Check-in to Your Profile > Select product > Customer Support > Search KB or Submit New Ticket, and do a search for KB #4897 and download the fixed A/P gauge.

I think this could fix your A/P problem.

Mark

it makes sense now :) i got FSXacceleration and mine AP works :)

I have accelleration, but i tried the fix anyway and no worky. Will check the GPS thing.

GPS looks alive. So probably not that either.

It has worked in the past and started doing this about a half dozen flight ago. When it does work, the pitch hold works and can be adjusted via the pitch/roll controller on the autopilot.

I think it has something to do with the flight director. If I leave it off, the autopilot behaves as expected. So either I'm not using it right, or its faulty. But it really shouldn't affect the autopilot function. I'm going to do some more testing with it and then maybe open a ticket. First I will wait to see if anyone has any insight.

thanks.

Do you have your elevator trim set for take-off?  What is your approximate airspeed and pitch angle at the moment you engage the autopilot?  Are you trimmed at that point, or are you keeping the yoke pulled back to maintain your initial climb angle?

CXA546 wrote on Oct 19^th, 2011 at 3:41am:

I think it has something to do with the flight director. If I leave it off, the autopilot behaves as expected. So either I'm not using it right, or its faulty. But it really shouldn't affect the autopilot function. I'm going to do some more testing with it and then maybe open a ticket. First I will wait to see if anyone has any insight. thanks.

yeah, i remember something about F/D doing so in -100. i just dont use it a lot. maybe that's the case. i'll make some flying in upcoming days, and see whats there :)

David Paul wrote on Oct 19^th, 2011 at 9:45am:

Do you have your elevator trim set for take-off?  What is your approximate airspeed and pitch angle at the moment you engage the autopilot?  Are you trimmed at that point, or are you keeping the yoke pulled back to maintain your initial climb angle?

The airplane is trimmed and climbing hands off before the autopilot goes on.

i made some flying last week, A/P itself works for me. But F\D...hmmm....hard to tell :) Anyway im not using it on takeoff, and after takeoff it works ;)

A\P or F\D can stuck after loading flight with engaged A\P, but thats not the current topic case i think.