Speed control?

[Noel 4,486]

I'm wondering how to use speed control in the Phenomenal Phenom, that is besides manual control of the throttle during cruise.

[FDEdev 955]

There is no autothrottle and no hence no speed control during cruise on the Phenom 300 (and most other biz jets).

[Noel 4,486]

What then are the 2 speed control buttons about?  They're clickable...

[FDEdev 955]

2 buttons?  With the SPD SEL button you can adjust the reference speed. In FLC mode the aircraft tries to maintain the set speed. 

[Noel 4,486]

Oh, so it has a way to modulate speed even if it's not an autothrottle per se.  How does it do that, by changing elevation, up to slow down, down to speed up?

It could be a misplaced tooltip over CSC or CPL I forget now but I think it said Speed Select or Control

Edited March 24, 2020 by Noel

[FDEdev 955]

4 hours ago, Noel said:

Oh, so it has a way to modulate speed even if it's not an autothrottle per se. How does it do that, by changing elevation, up to slow down, down to speed up?

No, you can't modulate speed. You can use FLC (flight level change) only to change the altitude.  Max (climb) thrust for climb and idle thrust during descent.  The AP only pitches the aircraft up/down to maintain the selected speed.

FLC isn't very comfortable IRL in anything than perfectly calm weather due to to constant pitch changes. 

[Noel 4,486]

2 hours ago, FDEdev said:

No, you can't modulate speed....The AP only pitches the aircraft up/down to maintain the selected speed.

FLC isn't very comfortable IRL in anything than perfectly calm weather due to to constant pitch changes. 

Yes that is what I had assumed, up and down to control speed.  Seems like it is modeled well because of as you say its constant pitch changes.  It's sometimes hard to control speed manually and I think that is because my throttle is low resolution.  As I move it very slowly to the next increment it's 5, not 1, which makes it hard to fine tune speed even w/ calm air.

Edited March 24, 2020 by Noel

[FDEdev 955]

A smoother climb can be achieved by using initially VS. Set the new target altitude, push the throttles full forward and increase the VS in small steps until the IAS doesn't (or only slightly) increase. At this point set the speed bug to the present speed and select FLC. 

This procedure works during descent at idle thrust as well.

The FLC button in the Phenom (IRL and in the sim) is actually mislabled since pushing this button doesn't change the FL. FLC works only in autothrottle equipped aircraft where thrust is automatically set to max climb or idle. 

[kenny584 77]

Emmm...Perhaps I am not doing things correctly but I use FLC mode to change altitude up or down and it works really well. For example, when departing on a SID, I have matched my indicated airspeed to the one I have selected and fly to the STOP altitude on the SID. Prior to getting there I select my preferred enroute FL and select a sensible airspeed. I advance the thrust until my indicated airspeed matches my selected airspeed, this should be within the detent range of CON/CLB, I then select FLC mode and the aircraft smoothly starts an ascent to the selected FL. For a descent, I select my desired airspeed and FL or altitude, then reduce the thrust until my airspeeds closely match and then select FLC wherupon the aircraft will commence a smooth descent. If ATC request a climb or descent then it is better to use the VS mode and adjust thrust to match the selected airspeed.

This works well for me.

Regards...Ken.