GC Align Hold

[Tinkickef]

Just started getting to grips with the 15.  I can navigate between waypoints and change waypoints manually when the aircraft is set to takeoff from parking hot.

However on cold start, I cannot get the GC Align to work reliably.  Tel Nof Airfield.  Some parking spots seem to work and others do not.

Thinking it might be because it is a shelter, I pull out into open air and try again.

Both engines started.

NAV button pressed on UFC.

NAV block is boxed on HSI.

NAV FLIR switch ON.

INS switch to GC Align.

Air con to auto and blasting air.

All I get on the HUD is GC HOLD and no alignment numbers counting down.

After a good five minutes, i switch from GC align to NAV and just get NAV Degraded on the HUD.

I must be missing something, but I cannot see what.  I have been back to the cold start tutorial several times.

 

Anyone see what I am doing wrong?

 

[falcon_120]

Currently, don't know if that will change, make sure of the following:

-Parking brake on
-No input to any device, rudders or joystick, avoid To trim while aligning.
-Make sure the rearm process does not happen when not aligned or it will trash the alignment
-Yaw, pitch, roll Cas off


With that I'm aligning alright always (6 MP alignment so far in different servers)

Enviado desde mi ELE-L29 mediante Tapatalk

[rubbra]

Parking brake on. That’s all you need. (And no rearming or control input to move the aircraft)

[YoYo]

Yes, I havent a problem with alignement but always Im using parking brake when the power will be present, works 100% all the time.

[dorianR666]

you mustnt touch your stick or pedals - at all.

if they get out of deadzone, the alignment is ruined.

 

some people on reddit also claim that strong wind can ruin it but i havent seen that happen.

Edited July 2, 2023 by dorianR666

[Despayre]

Discovered if you switch it INS Align, and then punch in the new coords from your kneeboard (mine weren't identical to what was showing on the UFC on cold start) it seems to bork the entire process. 

Leaving the coords that showed up initially worked just fine, with and without the parking brake on.

[Tinkickef]

Thanks guys.  I think the elephant in the room is the parking brake.  Sometimes I ask for the chocks removing and set brake hold early on, and sometimes later when getting ready to taxi.

So brake hold on as soon as I have AC power from the engines...

[YoYo]

34 minutes ago, Tinkickef said:

Thanks guys.  I think the elephant in the room is the parking brake.  Sometimes I ask for the chocks removing and set brake hold early on, and sometimes later when getting ready to taxi.

So brake hold on as soon as I have AC power from the engines...

Chocks are not needed (you can remove it by ground crew) but PB is obligatory before start of align process. 

[Despayre]

5 hours ago, YoYo said:

Chocks are not needed (you can remove it by ground crew) but PB is obligatory before start of align process. 

That may be the desired intention, but that's just not true.

At no time during this alignment, nor at any time from a cold and dark start, did I turn on the parking brake, and as you can see, it aligned just fine. I did have wheel chocks though (but I agree, I don't think they were needed, I just didn't remove them).

[Raven (Elysian Angel)]

1 minute ago, Despayre said:

That may be the desired intention, but that's just not true.

It is IRL, and it should/will be like this in DCS as well, but apparently it's not yet implemented. It's better to get into the correct habit though

[Despayre]

8 minutes ago, Raven (Elysian Angel) said:

It is IRL, and it should/will be like this in DCS as well, but apparently it's not yet implemented. It's better to get into the correct habit though

Absolutely, but that doesn't change the fact that it isn't that way.

 

[Rainmaker]

12 hours ago, Raven (Elysian Angel) said:

It is IRL, and it should/will be like this in DCS as well, but apparently it's not yet implemented. It's better to get into the correct habit though

it is not

[Raven (Elysian Angel)]

Oh, apologies then. I was pretty sure I read that here on the forums.

[bfr]

My experience to date is get everything else spun up first, make sure the plane can't move itself (chocks and/or PB) and then don't touch a damn thing once its aligning. The annoyance though is that there doesn't seem to be an obvious way to restart the alignment process (other than restarting the mission) if you do upset it and it drops into the GC Hold state?

[Despayre]

2 hours ago, bfr said:

My experience to date is get everything else spun up first, make sure the plane can't move itself (chocks and/or PB) and then don't touch a damn thing once its aligning. The annoyance though is that there doesn't seem to be an obvious way to restart the alignment process (other than restarting the mission) if you do upset it and it drops into the GC Hold state?

I found that after the full alignment borked, if I turned it off and back on to stored heading alignment, that worked... but if I borked that too, ya, no other way to restart it that I found either (that worked).

[Tinkickef]

Finally found the problem. 

Canopy open. 

If I closed the canopy as soon as the right engine started producing AC power and then ran through the rest of the start up sequence normally, the INS would count down to ok.  This is where I was differing from the cold start tutorial as I like to taxi with canopy raised.

Whether this is a real feature or a bug I have no idea.  Cannot see canopy affecting alignment IRL.  Seems odd if so.

[Rainmaker]

2 hours ago, Tinkickef said:

Finally found the problem. 

Canopy open. 

If I closed the canopy as soon as the right engine started producing AC power and then ran through the rest of the start up sequence normally, the INS would count down to ok.  This is where I was differing from the cold start tutorial as I like to taxi with canopy raised.

Whether this is a real feature or a bug I have no idea.  Cannot see canopy affecting alignment IRL.  Seems odd if so.

Its being addressed.  For some reason, the INS got so sensitive, it would go into hold if a feather landed on the wing.

[bfr]

5 hours ago, Despayre said:

I found that after the full alignment borked, if I turned it off and back on to stored heading alignment, that worked... but if I borked that too, ya, no other way to restart it that I found either (that worked).

Interesting, might try that next time I stuff it up. Although surely its not unreasonable to expect that turning it off and then back to GC Align should do what I want? (I think that 1993 flight manual that was doing the rounds suggests you can restart an alignment by turning it off for >5 seconds and then retrying).

EDIT: Just retried it in light of the stuff from the flight manual and leaving it at OFF for a while (5s possibly not enough, left it for about 10s) does seem to work in terms of restarting alignment.

Edited July 3, 2023 by bfr

[Guest]

Just starting the engines with only the necessary systems on to do that and then align and wait till finish before doing anything else, works 9/10 times for me.

[Sydy]

On 7/2/2023 at 12:40 PM, YoYo said:

Chocks are not needed (you can remove it by ground crew) but PB is obligatory before start of align process. 

I will change my Quick Checklist (to vs 1.2) to reflect that. Tks a lot..

[Sydy]

1 hour ago, Sydy said:

I will change my Quick Checklist (to vs 1.2) to reflect that. Tks a lot..

Updated: (vs 1.2) - Brake Hold before INS Alignment and TPOD to stby during descent steps added.

[Lord_Pyro]

On 7/2/2023 at 5:40 PM, YoYo said:

Chocks are not needed (you can remove it by ground crew) but PB is obligatory before start of align process. 

For me it was the other way around. I rarely use the pb from the pit.

 

Btw: lowering the hook does also kill the alignmentprocess