A/T disconnected with rudder twist

[Virgin_A340 0]

I have a Saitek Cyborg Fly 5 joystick with a twist grip for the rudder. I use this to keep on the centre line during the takeoff roll in the 777. However when I get up some speed and need to twist the rudder to keep in line it always put the A/T into hold mode rather than keeping in TOGA. Is this a known problem and are there any solutions? This only happens with the PMDG 777 and no other addons I have including ones from PMDG.

 

Thanks for any help.

 

Andy Solaini

[KriVa 307]

The moment you twist the stick, doesn't happen to be around 80 knots, does it?

If it is, it's SOP for the 777 to announce HOLD at that point.

 

Also, full names are mandatory here, forum policy.

PS: It might also be a good idea to do the Tutorial flight, it's a really useful piece of information ;-)

[Virgin_A340 0]

Yes I think it would be somewhere around 80 knots. I thought it was probably something the 777 was doing deliberately rather than a bug in the software. It's a bit annoying thought because I either have the throttle problem or I end up going off the runway if there is any kind of wind on the plane.

 

PS - I have done the tutorial and it was informative but doesn't deal with this issue I am having.

 

Andy Solaini

[KriVa 307]

As far as I can see, there is no issue here. It's normal for the FMA to announce HOLD at 80 knots.

It has nothing to do with the rudder being twisted, because it should always happen when using TO/GA on take off.

What "throttle problem" are you having? Do the throttles retard? If so, you're supposed to use them like this:

When lined up, push them up to about 55% N1. Then push TO/GA. When you see the engine indication going up, follow it with your hardware throttles, or just push them all the way forward.

This procedure is outlined in the Tutorial flight, along with the different modes for the hardware throttles. Although the latter part is probably explained in the introduction manual ;-)

My apologies if I came across a bit harsh in my first reply, it's been a long day.

[g_precentralis 191]

If you do not like it or there's a problem with throttle quad, you can always disable that behavior in PMDG 777 options.

[Virgin_A340 0]

As far as I can see, there is no issue here. It's normal for the FMA to announce HOLD at 80 knots.

It has nothing to do with the rudder being twisted, because it should always happen when using TO/GA on take off.

What "throttle problem" are you having? Do the throttles retard? If so, you're supposed to use them like this:

When lined up, push them up to about 55% N1. Then push TO/GA. When you see the engine indication going up, follow it with your hardware throttles, or just push them all the way forward.

This procedure is outlined in the Tutorial flight, along with the different modes for the hardware throttles. Although the latter part is probably explained in the introduction manual ;-)

My apologies if I came across a bit harsh in my first reply, it's been a long day.

No you didn't come across as harsh Thomas. I probably didn't explain it well in my initial post but the throttles retard and the message on the PFD says something like "throttle hold" but I can't remember the exact wording. Maybe I will re-read the tutorial flight as it's been a long time since I read it. I might have missed or forgotten something...

 

Andy Solaini

[KriVa 307]

Are you sure your hardware throttles are fully forward? (The actual throttles you use to control your sim, probably on or near the joystick/yoke you are using)

If they are actually at idle, the engines should spool down, since HOLD just means the engines should follow exactly what your hardware throttles are doing. It means you're actually manually controlling the thrust.

[Virgin_A340 0]

Actually not there are not fully forward. I advance throttles to 60% N1 to let the stabilise then hit TOGA but leave the throttles where they were. So not at idle but not fully forwards. This is the technique I have used in about 10 years of simming and it's only on the 777 that it throws up a problem, the NGX I do the same but it's fine, for example. Maybe it's just that the 777 is more advance and realistic?

 

Andy Solaini

[KriVa 307]

Not sure about the NGX anymore, since it's been a while since I've flow her. (I know, I know, shame on me!). So I don't really remember if the FMA also announces HOLD there.

But at least in the 777, you really do need to advance the throttles all the way after having hit TO/GA.

Then your problem will be solved.

From page 44 of the introduction manual (bold emphasis mine):

 

 

Proper takeoff procedure with respect to your physical throttle:

o Advance the throttles to 55%

o Press TO/GA (don’t use the MCP A/T button, it takes half a second or so to "capture")

o Wait until you see THR REF annunciated on the FMA.

o Push the throttles fully forward. They are dead now because the AT is active. 

[Virgin_A340 0]

Thanks very much for that Thomas I will try it on my next flight.

 

Andy Solaini

[Mike777 163]

 

 

Actually not there are not fully forward. I advance throttles to 60% N1 to let the stabilise then hit TOGA but leave the throttles where they were. So not at idle but not fully forwards. This is the technique I have used in about 10 years of simming and it's only on the 777 that it throws up a problem, the NGX I do the same but it's fine, for example. Maybe it's just that the 777 is more advance and realistic?

 

As Thomas said, "Hold" is normal behavior.  It allows the pilot to quickly reduce thrust in a rejected takeoff without having the autothrottle fight his or her actions.  I usually do what you describe, but being careful not to touch the throttle control on my joystick.  If I don't touch it, the PMDG throttle won't sense the position of my throttle control.  But if I accidentally nudge it, then the position is sensed and the thrust will roll back.  Is it possible you are inadvertently touching your throttle control when twisting the joystick's rudder axis?

 

Mike

[Virgin_A340 0]

As Thomas said, "Hold" is normal behavior.  It allows the pilot to quickly reduce thrust in a rejected takeoff without having the autothrottle fight his or her actions.  I usually do what you describe, but being careful not to touch the throttle control on my joystick.  If I don't touch it, the PMDG throttle won't sense the position of my throttle control.  But if I accidentally nudge it, then the position is sensed and the thrust will roll back.  Is it possible you are inadvertently touching your throttle control when twisting the joystick's rudder axis?

 

Mike

Mike I see what you are saying but I think it's very unlikely that I'm accidentally nudging the throttles. I say this because they aren't really in a position where you'd nudge them and also the fact that it happens on every takeoff I do with the 777 makes me think it's unlikely I would nudge it by accident every time.

 

Andy Solaini

[KriVa 307]

Don't forget that a lot of hardware, especially when it gets older, actually produces little spikes (or noise), even when stationary. These spikes actually make FSX pick up on where the throttle is, and make the 777 think that you moved them while in HOLD.

So again, just push 'em completely forward, and you should be fine.

[Simicro 247]

Don't forget that a lot of hardware, especially when it gets older, actually produces little spikes (or noise), even when stationary. These spikes actually make FSX pick up on where the throttle is, and make the 777 think that you moved them while in HOLD.

So again, just push 'em completely forward, and you should be fine.

 

Thanks.

 

I've just changed my joystick and had the issue.

 

With the old one, after pressing TOGA, I COULD push my joystick throttle full forward later, after take-off.

 

With my new one, after pressing TOGA I MUST push my joystick throttle full forward rapidly otherwise, like you say, even if I don't touch the throttle, FSX senses that it is not full forward and TOGA mode is ruined.

[g_precentralis 191]

Wouldn't you get a full thrust if you push your hardware throttles full forward regardless of TOGA? I just set it to carrots at N1 arc after TOGA is engaged and before 80kt.