Default FSX 737 Autopilot - manual heading control

Hi all,

 

I could use some clarification around the use of the default FSX 737 autopilot in respect of heading control (I'm new to the heavies).

 

I've been using the Secret Shuttle mission as a test.

 

After successful takeoff, I arm the auto-throttle and turn on the auto pilot.

 

I turn on the Altitude control and Speed control autopilot functions only. I do not turn on and of the NAV functions.

 

I find that I'm unable to control the heading of the aircraft manually when autopilot is engaged (even though none of the NAV functions are engaged).

 

Is this normal operation of the default FSX 737? Does this mean when the autopilot is engaged, the only way to control manual direction is to enable the HDG autopilot function and use the heading selector bug?

 

Thanks everyone,

 

Trent

From FS98 through FSX,

737 or 172 the AP's basically work the same.

 

If Nav and Heading are off (not clicked)

manual control SHOULD work.

 

If your manual control doesn't work,

you need to consider a reinstall of FSX.

Sounds as if the wing leveler is engaged (this is normal). There's probably a button on the autopilot control to toggle this, but you can also use CTRL-V to toggle the wing leveler.

Turn the heading on and off.

Ha ha! The unseen wing leveller! This autopilot button doesn't exist on the default 737 2d panel or virtual cockpit so I had no idea what was going on...

 

I've tried again, used ctrl + v and that did the trick. Google searches for "FSX autopilot wing leveller" have yielded better results and I now know that I can edit the aircraft.cfg file to have this disabled by default anytime I engage the autopilot.

 

However, I'd like to ask if anyone knows of any panel / virtual cockpit fixes for this, ie. the addition of the wing leveller button?

 

Probably not, but it can't hurt to ask right?

 

Thanks everyone! I was tearing my hair out there for a little while...

 

Trent

Ha ha! The unseen wing leveller! This autopilot button doesn't exist on the default 737 2d panel or virtual cockpit so I had no idea what was going on...

 

I've tried again, used ctrl + v and that did the trick. Google searches for "FSX autopilot wing leveller" have yielded better results and I now know that I can edit the aircraft.cfg file to have this disabled by default anytime I engage the autopilot.

 

However, I'd like to ask if anyone knows of any panel / virtual cockpit fixes for this, ie. the addition of the wing leveller button?

 

Probably not, but it can't hurt to ask right?

 

Thanks everyone! I was tearing my hair out there for a little while...

 

Trent

 

Interesting! I can't find anything in the default 737-800 aircraft.cfg [Autopilot] or anywhere that refers to wing leveling. I might try the Secret Shuttle Mission and leave the Heading Hold off and see if I can manually fly the heading.

 

+1 on Ctrl+V to kill the wing leveler. Never tried using A/P and heading hold off before.

Switching ap on switches it on. Hdg hold on then off, switches it off.

Switching ap on switches it on. Hdg hold on then off, switches it off.

 

Will try that! Also saw a 2010 post from N4gix about adding this to the [Autopilot] section

 

[autopilot]

default_bank_mode=1

default_pitch_mode=1

I'm just now realising that the thing I was saying that switches on and off, is not the wing leveler so much, as more the "attitude hold" function. (which holds the nose up).

 

It may actually switch both the WL and ATT-hld on (and off). No time to test now.

Actuy, using altitude-hld would already defeat the att-hld function.:p

 

Enjoy testing Zip, I may join in that later.:cool:

Ps: if same issue in a321, switch off FAC(1 and 2) and ELAC (1 and 2).

(Overhead.)

I took a look at the default 737 [autopilot] entry in the aircraft.cfg. ASSuming there've been no changes to it, this is my conclusion: Notice there is no line in it thus default_bank_mode. Reading the SDK on that line yields this

This determines the default bank mode when the autopilot logic is turned on.

0 = None

1 = Wing Level Hold

2 = Heading Hold (current heading).

If no value is set, Wing Level Hold will be the default.

 

From what I read, you can add the line default_bank_mode=0 to prevent the wing leveler OR heading hold activating when activating the AP.

 

To keep the Attitude Hold from activating, add the line default_pitch_mode=0.

Again, from the SDK:

This determines the default pitch mode when the autopilot logic is turned on.

0 = None

1 = Pitch Hold (current pitch angle)

2 = Altitude Hold (current altitude)

If no value is set, Pitch Hold will be the default.

 

Adding in those two lines, to any AP section of an aircraft.cfg will keep the AP from holding either pitch nor roll, thus keeping the entire maneuver capability (big words, huh?? :D ) of the aircraft free for the pilot to determine.

 

I would make sure the Yaw Damper is NOT active as well. That tends to limit the rudder's throw, limiting turns. Thus, if off, the rudder's full throw remains available to the pilot. Maybe a bit much for most passengers, as the pilot could really crank the plane around, but if you need to make tight turns for a mission or whatever, well...

 

Hope this helps a little...

Pat☺