Hi,

I'm seeing strange behaviour when doing circuits in the A320.

I approach on ILS, land and decide to go around then do the following.

Flaps up one
TOGA GO-Around
+Rate - Gear Up
Pitch 15 degrees
Check A/THR engaged
Throttles to FLX then to CLB
Trim is UP as required
Hand fly to between 1500 and 2000 on runway heading
Select Autopilot 1

Now things start to go wrong!
The Horizontal Flight Director Command Bar plummets into a dive and the aircraft quickly follows.
I take control and recover to a steady 15degree climb.

Select Autopilot 1 again
Once again, the Horizontal Flight Director Command Bar plummets into a dive and the aircraft quickly follows.
I take control and recover to a steady 15 degree climb again and hand fly to the downwind leg.

Eventually on downwind leg at steady altitude and level pitch, I select Autopilot 1 and the aircraft behaves normally.
Thereafter no problem untill the next touch and go climb out.

Can anyone advise what I'm doing wrong during the climb out phase, that's making the Flight Director command a dive please ? Is it something I''ve miss-programmed into the MCDU?

I have posted on FSLabs Forum but no replys after 80 views!

Thanks in anticipation

Edited February 20, 20215 yr by ampharoah

6 minutes ago, ampharoah said:

Flaps up one

Flaps up one step , ( FULL to 3 or if landing FLAPS 3 , 3 to 2 )

10 minutes ago, ampharoah said:

Trim is UP as required

No Trim input is required, AutoTrim works for you.

Thanks for replying. When I say one step, I mean Flaps Full up one step to Flaps 3, or if Flaps 3, then one step up to Flaps 2. I use the PFD as normal, to indicate the further step up points as the speed builds.

Yes, I was worried that somehow the trim was finding its way to DOWN. However, after a few checks, it's for sure not a Trim problem.

I can't understand why the AP decides to dive every time its engaged. Watched YouTube vid after YouTube vid on this and no-one seems to do anything different to what I'm doing, but for some reason the AP wont behave.

Andrew

Edited February 20, 20215 yr by ampharoah

Hi,

Very strange indeed. Just a small question, what was the FMA showing when you increase to TOGA? And what was the display on the MCDU APPR page?

 

How about your altitude setting? Missed Approach altitude?

On increase to TOGA, FMA displays MAN TOGA / SRS / GA TRK / CLB (blue) / NAV (blue), MCDU displaying APPR information, Levers are at TOGA. 3000 set in ALT window.

On climb out at 15 degrees 1000ft, MCDU continues to be on APPR page, FMA showing MAN TOGA / ALT*/NAV A/THR (blue)

At 2000 MCDU still on APPR page, FMA showing SPEED / ALT* / NAV / A/THR

At 3000 MCDU still showing APPR page, FMA showing SPEED / ALT /  HDG / NAV (blue) / A/THR

Engage AP 1 aircraft starts a fast descent. Speed accelerates and things get messy!

 

 

 

 

Edited February 20, 20215 yr by ampharoah

1 hour ago, ampharoah said:

MCDU still on APPR page

So you never enter to GO AROUND phase, probably you're not sequence F/PLN properly. 

I find that the MCDU goes into GO AROUND phase some way along the downwind leg.

1 hour ago, ampharoah said:

I find that the MCDU goes into GO AROUND phase

FLIGHT PLAN SEQUENCING 

 

When in NAV mode, the F-PLN will sequence automatically. In HDG/TRK mode, the F-PLN waypoints will sequence automatically only if the aircraft flies close to the planned route. Correct F-PLN sequencing is important to ensure that the planned missed approach route is available in case of go-around and to ensure correct predictions. A good cue to monitor the proper F-PLN sequencing is the TO waypoint on the upper right side of the ND, which should remain meaningful.

Thanks polosim

Thats very useful and much appreciated.

Still not sure what I'm doing wrong here, but will look into this further.

Not sure what they mean by "flying close to the planned route".but I notice that on climb out NAV is displayed and not GA TRK. Perhaps I'm deviating too far from the 190 Runway center line on climb out?

Also not sure what "TO waypoint on the upper right side of the ND, which should remain meaningful" means?

I'll experiment.

Thanks again.

Hello,

I just tried GA with FSL A320, MCDU showed GO AROUND page, FMA showed GA TRK and GA altitude, TOGA thrust. Manual fly is ok, after engage AP the FD went immediately nose dive which I had to disconnect AP.

Tried twice and same thing happen. Hmmm, will try another test again now.

As long as I do not engage the AP, the FD behavior is normal. Right after engaging AP (1 or 2) the FD went down, literally pitch all the way down.

Hoang Le

UPDATED: it happens only if I GA during manual flying. Keep AP and GA works normally.

Edited February 22, 20215 yr by Hoang

Thanks for taking the trouble to assist and for confirming what I am seeing Hoeng. I thought I was going mad! I always take over from the AP, touch down manually and then rotate and switch on AP. Thats when I'm seeing the problem.

I will try a go around while still on AP.

Andrew

Hoeng, likewise I have managed perfect Go-Arounds provided that I don't disconect the AP and land. Go Around at 500ft AP on performs perfectly.

I have posted a help request with FSLabs.

Andrew

9 hours ago, ampharoah said:

Hoeng, likewise I have managed perfect Go-Arounds provided that I don't disconect the AP and land. Go Around at 500ft AP on performs perfectly.

I have posted a help request with FSLabs.

Andrew

Looking forward to the answer from FSL. I have found some other bugs/errors too however they seem to ignore my post over their forum. 

Edited February 23, 20215 yr by Hoang