EAC switch

[Pinefang]

Can someone tell me what start up requirements there are to engage the EAC switch located behind the throttle quadrant. I attempt to throw the switch but it moves back to the off position. I usually take off and try it later in the flight and it will usually stay on after awhile. Is there a time requirement for activation?

[RagnarDa]

Welcome to DCS:A-10C! Do this: make sure you have electric power (ask the groundcrew), turn on the CDU, wait three minutes until NAV READY starts flashing and choose *NAV on the CDU. Push EGI forward/behind the joystick. Turn on all the SAS channels on the left panel. Turn on the switch next to EAC (don't remember what it is) and THEN turn on the EAC ;)

[ralfidude]

And by 3 minutes he means 4.

 

So basically here is the deal.

 

The EAC switch can ONLY and ONLY be turned on after the CDU has done it's internal navigation aligment, which starts automatically when you flip that CDU switch underneath the CDU keyboard by your right knee.

 

So when you start the plane up, assuming you are going through the procedure correctly, you watch the CDU page and wait the 4 minutes till it hits 4.0.0.8 or so, on the top left of the CDU you will see flashing NAV READY!

 

WOHOO!

 

But, then you need to select NAV from the right side of the CDU page, a STAR will appear next to it.

 

THEN, you need to look infront of your stick and select the EGI button, since we don't want to use HARS (Which is an old navigation system used as a back up in case EGI fails).

 

NOW, that EGI is on, we can finally select our EAC switch ON!

 

 

So in short EAC is dependent on EGI being on, and EGI is dependent on the internal navigation being done aligning (4.0.0.8) and NAV being selected afterwards.

 

Kapish?

 

 

PS: Correction from what Ragnar said, EAC is NOT dependent on the SAS switches being on or off before you flip the EAC switch on. You can flip the SAS switches on anytime after the engines are on, before or after flipping the EAC, it won't matter.

Edited August 25, 2013 by ralfidude

[PreAmp]

Exactly what Ralfidude said!

I would like to add the following:

 

I can't find the thread where I got this from anymore, but it's important to wait untill the alignment is complete (4 minutes and FLASHING "nav ready" on CDU).

If you press NAV (on cdu), the EGI switch, or the EAC switch before that the system will (eventually) end up in a degraded mode, which will make it less accurate.

The only way to restore that is a complete realignment...

 

Indeed, the SAS switches and the NAV switch (the one below the thrust levers) CAN be set before alignment without any problems.