CptSmiley 3rd Party Developer



Join Date: Apr 2009 Posts: 1,050





This secondary mode is used in the event of sensor failure (typically pitot-static and/or AOA indicator failure). Going into Backup/Secondary mode will no longer use dynamically adjusted gains based on the sensors and no longer trust them. It will maintain constant control gains to a value that will work within the envelope seen below. Going outside of this envelope control is not ensured. Also, even with in this envelope control may be difficult as the control gains are not being optimally adjusted to assist the aircraft. Avoid steep climb/dive and enter the safe flight envelope and retract SLATs manually if extended.



We will adjust the manual and key binding name and tool tip accordingly.



On landing with FBW Backup/Secondary (Emergency) mode, another set of constant gains are used to aid with landing spending flight envelope.







We are also looking into the logic of what happens with the FBW reset (to the left of the switch).



Previously the way that switch was modeled is that it completely disconnected all control law algorithms (gave pilot direct input to the FBW essentially). The way the switch functioned was not a reasoning for the amazing high alpha behavior but that was mostly due to a combination of high alpha aerodynamics issues, engine performance modeling, and control response/effectiveness at high angles of attack allowing you to do maneuvers that shouldn't be possible. So have fun doing your back flips while you can. I had absolutely no clue that switch would become the most popular switch in the cockpit.



I hope this helps! Hey guys, so I wanted to give you a heads up on a big change to the FCS disconnect logic. We got some updated information on this switch. It is, more correctly, called the FBW Gain switch. Normal operation is what you normally expect. What is now the FCS disconnected is actually Backup/Secondary (or emergency mode).This secondary mode is used in the event of sensor failure (typically pitot-static and/or AOA indicator failure). Going into Backup/Secondary mode will no longer use dynamically adjusted gains based on the sensors and no longer trust them. It will maintain constant control gains to a value that will work within the envelope seen below. Going outside of this envelope control is not ensured. Also, even with in this envelope control may be difficult as the control gains are not being optimally adjusted to assist the aircraft. Avoid steep climb/dive and enter the safe flight envelope and retract SLATs manually if extended.We will adjust the manual and key binding name and tool tip accordingly.On landing with FBW Backup/Secondary (Emergency) mode, another set of constant gains are used to aid with landing spending flight envelope.We are also looking into the logic of what happens with the FBW reset (to the left of the switch).Previously the way that switch was modeled is that it completely disconnected all control law algorithms (gave pilot direct input to the FBW essentially). The way the switch functioned was not a reasoning for the amazing high alpha behavior but that was mostly due to a combination of high alpha aerodynamics issues, engine performance modeling, and control response/effectiveness at high angles of attack allowing you to do maneuvers that shouldn't be possible. So have fun doing your back flips while you can. I had absolutely no clue that switch would become the most popular switch in the cockpit.I hope this helps! __________________

"Witness mere F-14s taking off from adjacent flight decks, gracefully canting left and right, afterburners flaming, and there’s something that sweeps you away—or at least it does me. And no amount of knowledge of the potential abuses of carrier task forces can affect the depth of that feeling. It simply speaks to another part of me. It doesn’t want recriminations or politics. It just wants to fly.”

― Carl Sagan