777 Thrust reverse bug still persistent in SP1c

[ozflyer 2]

yes, for us as well.

But were you clicking F2 a single time, a few times or holding F2 down permanently?

I have reversers setup on the CH eclipse yoke, the red lever, and have axis assigned thru fsuipc.

 

How can I assign a constant F2 to an axis ?.

 

Thanks

 

Hari

[Sam 68]

Check repeat command box

 

I did this and still have the issue :/

[kevinh 409]

 

 

Then I tried two landings where I just held F2 after touchdown (no repeated clicking).

And on those landings the reversers DID open before the nose touched down!



So my conclusion is that the REV do work as they should, but you have to hold F2 down the whole time.

Clicking repeatedly will not send the commands to FSX as quickly as pressing and holding F2. Each F2 press moves the throttle a certain amount. Pressing and holding will move it continuously. Did you press F1 first to force the levers to idle?

 

I haven't watched this closely since SP1c so I'll take a look at how mine is and whether the reverser restow problem has been fixed for me.

[downscc 1,327]

I've drawn the conclusion that nothing is broke.. the original problem we had during SP1 testing was fixed. Many people see the behavior that is expected and few do not. Instead of watching the exterior of the plane during landing, watch the EICAS which will annunciate REV as soon as they go into transit and then lock. Also watch N1, because if that big fan (128 in diameter) has not yet spun down to idle then the reversers will not deploy.

 

A couple things I think could interfere with expected behavior is 1) No flare, not giving engines time to spin down 2) Improper throttle controller application not allowing idle until manually hitting F1 and 3) FSUIPC.ini needs flushing.  These are just guess, because I cannot duplicate the problem reported here.

[scandinavian13 5,192]

 

 

A couple things I think could interfere with expected behavior is 1) No flare, not giving engines time to spin down 2) Improper throttle controller application not allowing idle until manually hitting F1 and 3) FSUIPC.ini needs flushing.  These are just guess, because I cannot duplicate the problem reported here.

 

Isn't there an A/T override option for the reverse, specifically, in the PMDG SETUP> menu to assist with this if a user's hardware is causing issues?

[kevinh 409]

On each landing it took several F2 clicks before the REV would activate (between 6 and 11 clicks).

And each time that last click that would activate the REV would happen to be at pretty much the same time the nose touched down.

 

Then I tried two landings where I just held F2 after touchdown (no repeated clicking).

And on those landings the reversers DID open before the nose touched down!

 

So my conclusion is that the REV do work as they should, but you have to hold F2 down the whole time.

 

Maybe some of you can try this as well to confirm?

Rob,

 

I just tried this for myself and despite a many attempts could not repeat the previous issue with SP1b where the reverser stowed again as the nose gear touched down. I was landing manually at Flap 20 to keep the speed high as I found the problem was speed related last time. SP1c seems to have fixed that for me.

 

Regarding T/R deployment (main gear touchdown, nose held off)), I tried landings with A/T engaged and disconnected. With A/T off, I only needed to press F1 once then F2 once to deploy the reverser. With A/T in SPD mode I had to hold F2 down to get the reverser to deploy. I suppose the manual lever input from the function keys is fighting with the A/T in the sim. I expect if I selected full time thrust lever override of A/T reverse might deploy as with A/T disconnected.

 

Nice to do some test flying with no automatics. The -200 behaved really well and I found I was trimming completely instinctively and quite accurately.

[777simmer 117]

Clicking repeatedly will not send the commands to FSX as quickly as pressing and holding F2. Each F2 press moves the throttle a certain amount. Pressing and holding will move it continuously. Did you press F1 first to force the levers to idle?

 

I haven't watched this closely since SP1c so I'll take a look at how mine is and whether the reverser restow problem has been fixed for me.

No I did not press F1....only F2.

 

Since all my tests were autolands the AT should have commanded the levers to idle anyway.

I've drawn the conclusion that nothing is broke.. the original problem we had during SP1 testing was fixed. Many people see the behavior that is expected and few do not. Instead of watching the exterior of the plane during landing, watch the EICAS which will annunciate REV as soon as they go into transit and then lock. Also watch N1, because if that big fan (128 in diameter) has not yet spun down to idle then the reversers will not deploy.

Still having N1 rotation should not matter.

 

As Kevin said, FSX only looks at TL position...not RPM.

 

You probably know the following, but in real life it is not a requirement that N1 is at idle either.....it is not like N1 rotation changes direction during reversing ;-)

Fwd thrust and Rev thrust both rotate the fan (and the rest of the engine) in the same direction...the only thing that happens is that the reverser doors open and change airflow direction.....so regardless of N1 speed the engines should reverse as long as the TL are at idle.

hitting F1 and 3) FSUIPC.ini needs flushing.  These are just guess, because I cannot duplicate the problem reported here.

Hitting F1 might help....even with AT engaged......it should not be required, but who knows, will try.

 

Deleting FSUIPC.ini is allways a good idea when things are not working right, yes.

Rob,

 

I just tried this for myself and despite a many attempts could not repeat the previous issue with SP1b where the reverser stowed again as the nose gear touched down. I was landing manually at Flap 20 to keep the speed high as I found the problem was speed related last time. SP1c seems to have fixed that for me.

Thx. I too think that this is a problem with my hardware (only the left engine restows when I use my hardware.....with F2 neither restows)

Isn't there an A/T override option for the reverse, specifically, in the PMDG SETUP> menu to assist with this if a user's hardware is causing issues?

Ah that is what that is there for?

 

Ok, will try next time. (I thought that was only there to be able to override AT in gusty conditions)

[downscc 1,327]

Here is a chance to learn something, I hope... of course the fan rotation is unchanged; however, I've read that the Boeing Reverse Thrust Interlock does not allow movement into the reverse thrust range until reversers are in position... and they don't move until EEC signals that the engines are in null thrust condition.  I am not sure on this, so any elucidation is appreciated.

[777simmer 117]

Regarding T/R deployment (main gear touchdown, nose held off)), I tried landings with A/T engaged and disconnected. With A/T off, I only needed to press F1 once then F2 once to deploy the reverser. With A/T in SPD mode I had to hold F2 down to get the reverser to deploy. I suppose the manual lever input from the function keys is fighting with the A/T in the sim. I expect if I selected full time thrust lever override of A/T reverse might deploy as with A/T disconnected.

Interesting.......but with AT off, and hardware TL at idle, one should not have to press F1 at all I think.

[kevinh 409]

Interesting.......but with AT off, and hardware TL at idle, one should not have to press F1 at all I think.

I think this is the heart of the problem. It shouldn't be necessary, but if the lever input FSX sees is not actually idle but above idle then F2 will initially have to move the lever to idle before the reverser will begin to deploy. The reason why this might be is to simulate flight idle. I've no idea how PMDG have done this on the 777, but on the NGX there was a strong indication that it was done by slightly increasing the thrust lever input FSX saw. During descent the engine looks to be at idle but pressing F1 is able to move the thrust lever further back to the idle stop. If the same technique has been used in the 777 then that would explain why T/R deployment is slow for people who use hardware throttles for reverse rather then the F1/F2 keys.

 

The real engine idle setting isn't like that. With FADEC it's done by increasing the commanded N1 or EPR for the lever position. The way it's simulated is probably due to FSX limitations. PMDG could increase the parameter indications on EICAS to make it look like flight idle, but the thrust and spool up characteristics would not be correspondingly affected so it would be rather pointless.

 

Of course for day to day simming pressing and holding F2 is enough. I never usually press F1 first. There will just be a small delay in delpoyment.

[kevinh 409]

Here is a chance to learn something, I hope... of course the fan rotation is unchanged; however, I've read that the Boeing Reverse Thrust Interlock does not allow movement into the reverse thrust range until reversers are in position... and they don't move until EEC signals that the engines are in null thrust condition.  I am not sure on this, so any elucidation is appreciated.

On the 767 (PW4000) the EEC opens the reverse interlock (which limits full reverse lever movement) when the reverser actuator is more than 60% deployed. The EEC also limits N1 demand to idle until the reverser is 70% deployed. Full reverse is available once the reverser is 90% deployed. The 767 EEC doesn't prevent the reverser deploying if N1 is too high.

 

I would expect the 777 T/R control system to be similar in concept though the details will certainly vary. According to the 777 CBT course the thrust lever position signals the EEC to initiate T/R deployment (the 767 uses microswitches and relays). The CBT does not mention that deployment is prevented if the engine N1 or EPR isn't near idle. This doesn't mean such an inhibit doesn't exist, but it's odd that it isn't mentioned.

[BrianW 124]

The throttle resolver angle needs to be less than 30 degrees for the reversers to deploy, the other requirements are that you’re on the ground, and the engine is running. There is no thrust rating requirement. As Kevin pointed out the sleeves need to be extended more than 60 percent before the reverse thrust lever interlock will clear permitting more than idle reverse.

 

As a side note PMDG actually modeled the engine running requirement, if you try to actuate the reversers on the ground with hydraulics pressurized and the engines off they won’t deploy.

 

Brian

[AlanB77L 0]

I'm struggling to get the reversers to engage too.

 

I have the option to display T/L position selected, so I have the blue marker/ring around the N1 gauge. What I've noticed, is that the A/T isn't actually commanding idle on landing, but something slightly more. The commanded N1 marker is slightly ''above" (higher RPM) the blue T/L marker with the T/L at idle. When I then press F1 or hold down F2, the white commanded N1 marker shakes, but doesn't actually drop down to match the blue T/L idle until about the time the nosewheel touches down. Only then do the reversers actuate.

 

I have tried the 'always override A/T setting', and this works as long as you keep F2 depressed. If you release it, it'll jump back to the white commanded N1 and the reversers will stow. Once the nosewheel is down (or whatever the crucial event is that happens then, I've had the same with the nosewheel held in the air), the commanded N1 drops to match the blue T/L marker and I can re-reverse and the power setting will stay where I've set it.

 

Incidentally, I've tested with the A/T flare override on and off - no difference. The T/Ls come to idle initially, but stop again at the commanded N1 markers (which they really shouldn't, I've overridden the A/T, haven't I?) until the 'special moment'.

 

Is anyone experiencing the problem seeing similar behaviour?

 

Chad

 

Edit: I've tried with A/T disconnected, but I lose the blue N1 ring to compare to the white (now manually) commanded N1. I still suspect it reduces to a higher N1 target, which requires holding down F2, first to get to the actual idle, then to actuate the reversers.

[777simmer 117]

I looked closer after a (real world) landing today and the reversers opened (REV changed from amber to green) while N1 was still spooling down through 36% (GE90-90B).

Idle thrust was 21-22%.

 

We use idle reverse thrust under good (normal) conditions and I would like to use that on the PMDG777 as well.

But so far that seems difficult, as holding down F2 will activate the reversers, but it will also give me more than reverse idle.

 

I still have to try and replicate Kevins reverser observation of AT engaged versus AT disengaged......but if I see the same here, then it will be hard to select idle reverse thrust after any landing with AT engaged.

[777simmer 117]

I'm struggling to get the reversers to engage too.

 

I have the option to display T/L position selected, so I have the blue marker/ring around the N1 gauge. What I've noticed, is that the A/T isn't actually commanding idle on landing, but something slightly more. The commanded N1 marker is slightly ''above" (higher RPM) the blue T/L marker with the T/L at idle. When I then press F1 or hold down F2, the white commanded N1 marker shakes, but doesn't actually drop down to match the blue T/L idle until about the time the nosewheel touches down. Only then do the reversers actuate.

 

I have tried the 'always override A/T setting', and this works as long as you keep F2 depressed. If you release it, it'll jump back to the white commanded N1 and the reversers will stow. Once the nosewheel is down (or whatever the crucial event is that happens then, I've had the same with the nosewheel held in the air), the commanded N1 drops to match the blue T/L marker and I can re-reverse and the power setting will stay where I've set it.

 

Incidentally, I've tested with the A/T flare override on and off - no difference. The T/Ls come to idle initially, but stop again at the commanded N1 markers (which they really shouldn't, I've overridden the A/T, haven't I?) until the 'special moment'.

 

Is anyone experiencing the problem seeing similar behaviour?

 

Chad

But that the reversers stow again, after initially opening up, you only have that when you use your hardware throttle right?

 

(With continuous F2 I do not have this problem, but with my hardware TL I do!)

 

What I am thinking is that maybe my TL give off a spyke signal while I am reversing. And because the TL are still at idle when I pull the reversers (I have a real B737 throttle quadrant).....a spyke IDLE signal would restow the reversers ofcourse (just like F1 would).

(I use FSUIPC by the way)

 

Any chance you could be having a spyke IDLE signal as well?