Weird LNAV/VNAV

[ErmakDimon]

I was flying on level 360 from ULLI to EDDK, with LNAV and VNAV on. I accidentally hit a button for A/P Servos toggle, and the VNAV started heading the plane up and down. I've levelled it off, reengaged VNAV. but then, I noticed that I was getting off the flight path. The flight directors were showing to turn right. The LNAV, VNAV and CMD A were engaged, nothing on the FMC. I've tried to go to HDG SEL, and noticed that the plane turned slightly right and went straight, not following my commands. I then turned the yoke to the left, which disengaged LNAV and showed a CWS R yellow on the PFD. I went onto the path, but when i let go of the yoke, it turned itself right again> I couldn't solve this issue while in the air, and i had to quit. While everything was happening, the pitch trimm also wanted to go somewhere all the time.

Please help me.

Regards,

                Dmitrii.

[ErmakDimon]

gizmo log:

 

GizmoLog.txt

[mmerelles]

Hi @ErmakDimon

a few comments:

1. as you already experienced never ever use ap_toggle xplane default feature because this aircraft is a complex boeing with very complex a/p modes primary, secondary and intrincated systems as per the real thing.

if you want to map a joystick button or key of your liking to disengage a/p on final approach, ixeg provides a custom command you have to map to your key or button "ixeg/733/autopilot/AP_disengage"

Once mapped you have to press it twice, first press to disengage and a warning sound will kick in, second press to acknowledge and cancel the warning. Just like the real thing.

 

2. i do not know exactly how far "ap_servos_toggle" will mess the ixeg 733 systems, so best course of action if this happens again should be -reset everything- and -re engage-:

-Clic the disengage a/p bar located below the a/p puttons

-Disable both FD switches left & right

-Re-engage FDs left & right

-Clic CMDA to engage A/P left

-Clic LNAV and VNAV to re-engage

 

In the mean time you have to fly manually. Also note when this happens the aircraft may become unstable, you are too high and too fast, desktop yoke hardware will result being very sensitive to operate the aircraft. And while you try to re-engage A/P it may keep disconnecting back because is receiving signals from the yoke overriding A/P.

So, also set the CWS nullzone slider bar on the aircraft preferences (left side menu) full to the right, this will prevent A/P disconnecting and going into CWS mode while you try to engage LNAV or VNAV but still controlling the aircraft.

 

hope this helps

 

 

 

[ErmakDimon]

11 hours ago, mmerelles said:

Hi @ErmakDimon

a few comments:

1. as you already experienced never ever use ap_toggle xplane default feature because this aircraft is a complex boeing with very complex a/p modes primary, secondary and intrincated systems as per the real thing.

if you want to map a joystick button or key of your liking to disengage a/p on final approach, ixeg provides a custom command you have to map to your key or button "ixeg/733/autopilot/AP_disengage"

Once mapped you have to press it twice, first press to disengage and a warning sound will kick in, second press to acknowledge and cancel the warning. Just like the real thing.

 

2. i do not know exactly how far "ap_servos_toggle" will mess the ixeg 733 systems, so best course of action if this happens again should be -reset everything- and -re engage-:

-Clic the disengage a/p bar located below the a/p puttons

-Disable both FD switches left & right

-Re-engage FDs left & right

-Clic CMDA to engage A/P left

-Clic LNAV and VNAV to re-engage

 

In the mean time you have to fly manually. Also note when this happens the aircraft may become unstable, you are too high and too fast, desktop yoke hardware will result being very sensitive to operate the aircraft. And while you try to re-engage A/P it may keep disconnecting back because is receiving signals from the yoke overriding A/P.

So, also set the CWS nullzone slider bar on the aircraft preferences (left side menu) full to the right, this will prevent A/P disconnecting and going into CWS mode while you try to engage LNAV or VNAV but still controlling the aircraft.

 

hope this helps

 

 

 

Thank you very much for this answer, I thought the aircraft was compatible with default settings. Ok, I'll set everything and I've already played with the nullzone so I think I found the right setting. Count as solved

[archibit]

Noticed a bug in following of the line of a route. I think that the autopilot seeks to turn the plane to the closest point of a route even if this point isn't the next first following point. For example when approaching to UUEE via UM24B after AD we should go 041 heading to next point and then turn right to OTNAS and only then approach to glide path. And the route on EHSI is right and correspond route on chart (only one thing - turn to OTNAS too sharp), but after passing AD plane turn directly to glide path and do not follow the route line on EHSI. VOR and APPR modes is off LNAV on, so plane should follow the route in this situation. 733 ver 1.0.7 navdata navigraph 1607 ver2

IXEG_FMS_debug.txt

GizmoLog.txt

 

Edited July 10, 2016 by archibit