Question about EAC arming

[Frogfoot1606687865]

Hi, I have noticed that when the EAC switch is set to ARM during the startup the EAC light on the warning panel remains illuminated, and for the first 10 minutes or so the autopilot.PAC etc is inoperative. Eventually however the light extinguishes and all is well. I understand that the EAC switch is solenoid held and can flip back if certain parameters are not met. I normally switch the EAC to arm after bot engines have spooled up and are providing power. And after the HUD BIT prompts to switch the EAC to ARM.

 

I don't know however what specifically causes this delay between the system being initialized and the systems becoming operational. What systems are initializing that the LAAP is dependent on? Is there a way to speed up the process? Have I done something wrong?

 

Cheers

Tom

[Sticky]

I think it was Kylania who made a pdf guide, I tried finding it for you but couldnt, maybe you can pm him for it.

 

Two requirements to arm the EAC system:

1. EGI must be fully aligned.

2. SAS switches must be in the upright position.

[Frogfoot1606687865]

Does the EGI have to be fully aligned, and SAS channels engaged prior to flipping the EAC switch to arm? I always wait until the 'INS NAV RDY' message is displayed before taxiing but have normally flipped the switch to arm some time before.

Thanks

Tom

[Sticky]

I was thinking maybe its better if you get it from his link, since he might have updated it, but I couldnt find it in a search, but anyway here is the one I downloaded from his link a few weeks ago.

EnablingEACInBeta3v1.pdf

[159th_Viper]

Does the EGI have to be fully aligned, and SAS channels engaged prior to flipping the EAC switch to arm?

 

As Sticky said, Yes.

[MTFDarkEagle]

Yes fully alligned. I.e. the INS NAV ready on the CDU has to flash. Then you are ready to click nav, and arm EAC. After engaging SAS channels obviously :)

[Frogfoot1606687865]

Thanks guys, you have both been a great help.

Tom

[BlueRidgeDx]

There are a few other things that will disengage EAC - or prevent it from being armed - in addition to the two items above:

 

Deselection of EGI on the NMSP (manual or automatic); manually selecting HARS, for example.

 

Selection of the GPS-only nav solution in the CDU.

 

Selection of the INS-only, or Blended nav solutions in the CDU, if the NAV solution (FOM) is degraded (already mentioned, sort of).

 

If any input sensor provides invalid or erroneous info (CADC, EGI, SAS).

 

Any SAS switch OFF (already mentioned).

 

Air-refuel door open.

 

Occasionally, during certain flight maneuvers.

[recoil17]

I engage my EAC switch once I start rolling into a taxi. The NAV light remains lit and the TAD says NO DATA until I start to roll. If I engage the EAC before I start to roll, it will not come on after I start to roll. I have to engage it after I start to taxi and it works fine.

[El_Roto]

I've lost autopilot on two occasions due to EAC turning off on its own. Once I couldn't get it to come back and the other time a few flips back and forth got it going again. These were training missions I'd started in the air.

 

Weird thing: sometimes I didn't hear a corresponding cockpit click when I cycled the EAC switch on my Warthog's throttle base. Interesting or trivial?

[MTFDarkEagle]

I suppose that's a non sync fault..

[MemphisBelle]

I think it was Kylania who made a pdf guide, I tried finding it for you but couldnt, maybe you can pm him for it.

 

 

I am in contact with Kylania and will try to ask him to share this pdf.

[Eggcake]

Thanks for the pdf on the first page, it helped :)

 

The problem is, that you don't have to wait for this in the training mission. So I assumed I can just enable NAV. Things cleared up now :)