Autothrottle for motorised thrust levers

[alpinflier 2]

Hi all

 

I would like to realise the A/T function in my homecockpit with motorised throttles, based on PMDG737NGX and P3D. As far as I know throttle levers are controlled by pilots as long as A/T is off or only armed. As soon as TOGA is selected, A/T is engaged and throttle levers are controlled by the PMDG. But there are additional changes between „armed“ and „engaged“ during takeoff and flight, e.g. the „THR HOLD“ at takeoff.

 

Unfortunately there are only two variables available in PMDG SDK to control external equipment concerning A/T:

- MCP_ATArmSw

- MCP_annunATArm

both indicating that A/T is armed. But they cannot be used to control the automatism of the levers as required. There should be a variable "A/T engaged" that reflects all the internal conditions and dependencies. Some functions could be realised by software using the variables above and some others as Speed, AGL, a.s.o., but that is quite complicate and will probably not cover all situations.

 

Therefore my question to PMDG : Is it possible to provide such a variable in the future ? It would help very much to realise a realistic A/T behaviour in home cockpits. If I’m wrong please let me know and have some hints to solve this problem.

 

Thanks for any comments

Urs Meyer

[scandinavian13 5,192]

 

 

There should be a variable "A/T engaged" that reflects all the internal conditions and dependencies.

 

This doesn't exactly make sense from a programmatic standpoint. The A/T being ARMED is a Boolean: TRUE or FALSE. The switch is up, or the switch is down.

 

 

 

Therefore my question to PMDG : Is it possible to provide such a variable in the future ? It would help very much to realise a realistic A/T behaviour in home cockpits. If I’m wrong please let me know and have some hints to solve this problem.

 

Some time after the 747 - which will have specific hardware-friendly support - the NGX is planned to receive an update along the same lines.

[alpinflier 2]

Hi Kyle

 

Thank you very much for this ultra fast answer :smile: . To be precise: I don't want to change the ATArmed variables, but I would need an additional variable (call it as you want to), that drives the coupling mechanism between my controlstand levers and the PMDG levers:

- controlstand drives PMDG levers, i.e. pilots may move the levers (manual control)

- PMDG drives controlstand levers, i.e. flight computer drives the levers (autothrottle)

 

If such a variable (boolean) could be realised for the planned update it would help a lot. If there are questions please let me know.

 

Best regards

Urs Meyer

[scandinavian13 5,192]

 

 

Thank you very much for this ultra fast answer .

 

You're welcome. We'll see when we're able to roll the change back into the NGX.

[alpinflier 2]

Hi Kyle

 

Sorry to bother you again. I tried to circumvent the missing variable above and was looking for a variable to show the "TOGA" mode, but without success. Is it correct that there is no sdk data available for that?

 

Best regards

Urs Meyer