I try to take off with managed altitude and heading, but i also want it not to exceed 220kts so i set the speed to 220kts but AP does not care and goes to the 250kts

Is this the way it suppose to behave or would the real airplane respect set speed and and stop accelerating once reached 220 set on the MIP...

Just to clarify I did set it to manual air speed so that 220 is displayed and the dot is gone

 

The only way i seem to be able to take off and hold the aircraft at desired speed is if I climb using AP hold vertical speed and then it will hold my set airspeed also, so..

 

AP Vertical speed Hold + Managed HDG = AP will hold selected air speed OK

Managed Alt + Managed HDG = AP selects speed by itself and doesn't care about set speed on MIP

 

I should add it happens only at take off, later in the flight it will hold my speed i selected all through the cruise and descent.

Using the FBW mod

Thanks

Hello, 

Do you have auto thrust (A/THR) selected on the FCU? 

 

Edited December 7, 20205 yr by gb09f

Did you pull the speed knob after selecting the speed?

At 1500' AGL you should pull the throttle back to the CLIMB detent and it will follow your speed using Autothrust - providing you have selected A/THR and as HeLord (good name!) says you have selected your speed and pulled the knob back on the MCP.

yes i did lower thrust to CL yes i did pull the knob, not sure what you mean by "... providing you selected A/THR..."

here's a video of the take off i made if you want you can take a look at it maybe you can spot something i did wrong but it shows and i try to explain what i am doing and what's going on

thanks

 

1 hour ago, AndyCYXU said:

yes i did lower thrust to CL yes i did pull the knob, not sure what you mean by "... providing you selected A/THR..."

A/THR selected on the MCP.

https://www.smartcockpit.com/plane/AIRBUS/A320.html

 

1 hour ago, AndyCYXU said:

yes i did lower thrust to CL yes i did pull the knob, not sure what you mean by "... providing you selected A/THR..."

here's a video of the take off i made if you want you can take a look at it maybe you can spot something i did wrong but it shows and i try to explain what i am doing and what's going on

thanks

 

I really hope its only the video and not how you really play. This looks like 10 fps.

I haven't actually never tried to take off or climb with selected speed. I think in real life you program climb speed in CLIMB PERF page or as a speed constraint to waypoints when lower than 250 knots is needed.

13 minutes ago, roi1862 said:

I really hope its only the video and not how you really play. This looks like 10 fps.

lol yes it's the video, and the fact of recording it it's ok when i actually just fly,  recording ON brought the video card to its knees I play in 4K also 😄 al ULTRA add recording on top of it and yeah

13 minutes ago, HeLord said:

I haven't actually never tried to take off or climb with selected speed. I think in real life you program climb speed in CLIMB PERF page or as a speed constraint to waypoints when lower than 250 knots is needed.

Try it see if it works for you...

Yes I tried setting it in PREF in CLB to 200 it didn't do anything, I am wondering if it has to do with more recent ASOBO adjustments to AP that is messing it up. Reason for that is when I use P2A they were complaining to keep speed below 220 kts also getting warnings from SelfLoading Cargo for speeding below 10000 ft, so I decided to set Manual speed and then i found out it doesn't work.

If i recall I haven't played it in a while 737 would never breach speed or altitude when flying FMC, but then again it was PMDG and it was in P3D so whole other story but i though A320 should respect this speed also, but then again some people can't even fly the word not allowed thing so i suppose this little hiccup can be dealt with

Found this. So according to this, it should be possible to take off with selected speed. I am not home right now, so I can't test it with FSLabs A320. 

The climb speed may be either: 
• Managed 
• SELECTED
MANAGED
The managed climb speed, computed by the FMGS, provides the most economical climb profile as it takes into account weight, actual and predicted winds, ISA deviation and Cost Index (CI). The managed climb speed also takes into account any speed constraints, e.g. the default speed limit which is 250 kt up to 10 000 ft.
SELECTED
If necessary, the climb speed can be either pre-selected on ground prior to take-off on the MCDU PERF CLIMB page or selected on the FCU as required.
On ground, prior take-off, speed target at acceleration altitude can be pre-selected on the MCDU PERF CLIMB page. It is to be used when the F-PLN has a sharp turn after take-off, when high angle of climb is required or for ATC clearance compliance. Once airborne, the speed can be selected on FCU to achieve the maximum rate of climb or the maximum gradient of climb.

 

31 minutes ago, Will Fly For Cheese said:

A/THR selected on the MCP.

https://www.smartcockpit.com/plane/AIRBUS/A320.html

 

yes ofcourse it's selected green light is ON

7 minutes ago, HeLord said:

SELECTED

 

If necessary, the climb speed can be either pre-selected on ground prior to take-off on the MCDU PERF CLIMB page or selected on the FCU as required.
On ground, prior take-off, speed target at acceleration altitude can be pre-selected on the MCDU PERF CLIMB page. It is to be used when the F-PLN has a sharp turn after take-off, when high angle of climb is required or for ATC clearance compliance. Once airborne, the speed can be selected on FCU to achieve the maximum rate of climb or the maximum gradient of climb.

 

right so this is exactly what I did selected it on FCU ... hmm... yeah if you want you can try it on a FSLabs let me know what happened, I do not own any add-on airbus on any other sim only PMDG 737

 

Thanks

yeah that problem (or me doing something wrong) was for a while, before most recent update which screed up autopilot all over but has since been fixed,

Looked at some older video I made and I was all excited that it held the speed but in fact I have moved the throttle below CL so I didn't allow it to go full climb thrust, so in fact it wasn't keeping the speed i just choked it.

Time stamp 33:15

 

Edited December 7, 20205 yr by AndyCYXU

You are too close to your selected speed and the speed is increasing too fast when you turn on the autopilot and reduce throttle to climb. The engines, not long the aircraft, have no chance to slow down in that time frame.

Your initial angle of climb needs to be steeper to keep your speed increase down.  The initial climb angle on an A320 should be between 15-20 degrees, you are only at ten. You can still turn your autopilot on and go to climb at the same altitude you did, but then the plane will be going slower and has time to respond.

Unfortunately, the PFD bars in the default do not give you proper direction, as you are supposed to be able to just follow them.