[Solved/No Bug] [1.0.5] MCP speed activates on GS capture.

[Tom Stian]

Hello

When flying with A/T armed only and doing an ILS approach, then the "MCP speed" will activate on GS capture as you can see in my video below

 

 

Edited May 30, 2016 by Tom Stian

[mgeiss]

Should be a case of "works as designed":

 

12 hours ago, Litjan said:

Also notice that the speed mode will automatically engage whenever a new pitch mode (alt hold, GS, vertical speed, etc.) engages, this is normal and a safety feature.

 

[Tom Stian]

2 minutes ago, mgeiss said:

Should be a case of "works as designed":

 

Just another pilot error then

Thanks

[Litjan]

4 minutes ago, Tom Stian said:

Just another pilot error then

Thanks

That´s why many 737 pilots find flying with the FD on tedious - you have to keep commanding "deselect SPD mode" to the pilot monitoring. Every time you change from FL CHG to ALT AQC, then again at ALT HOLD, when changing to V/S or FL/CHG or G/S, and so on...

I think some airlines allow, or even encourage flying manually with the autothrottle in SPD mode - which I think is bad practice, because it leads to uncontrolled pitching because you never know when the A/T adds or removes thrust...

Jan

 

[Tom Stian]

5 minutes ago, Litjan said:

That´s why many 737 pilots find flying with the FD on tedious - you have to keep commanding "deselect SPD mode" to the pilot monitoring. Every time you change from FL CHG to ALT AQC, then again at ALT HOLD, when changing to V/S or FL/CHG or G/S, and so on...

I think some airlines allow, or even encourage flying manually with the autothrottle in SPD mode - which I think is bad practice, because it leads to uncontrolled pitching because you never know when the A/T adds or removes thrust...

Jan

 

Ok. I could disarm the A/T, but I remember from one (or more) of your videoes that you recommended leaving it in armed. Since you then have the speed protection. 

I havent tested it, but will speed engage with autopilot off also ?

[Litjan]

No, if the autopilot and flight-director are off, the A/T will only kick in when it´s reversion modes are triggered. But if either AP OR FD (or both) are on, it will engage in MCP SPD on any pitch mode change - except for a FL CHG descent, in that case it will engage in RETARD.

Jan

 

[Tom Stian]

Thanks for your explanation and time Jan.

Guess you can move this to solved.

Have a nice day.

[Tom Stian]

Sorry to bring this old topic alive again.

But have an other similar situation.

Im full established ILS with A/T armed. No MPC speed engaged. And with one autopilot.

If I engage the second autopilot for a CATIII landing the MCP SPD will engage. Is that intended as well ?

[Litjan]

Hi Tom,

I am not totally sure if there is an extra logic in place if one AP is already in CMD...but usually the A/T will engage in MCP SPD if an AP is turned from OFF to CWS or CMD. So, yes, the behaviour is intended as we coded it.

Cheers, Jan