777 Thrust reverse bug still persistent in SP1c

[AlanB77L 0]

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?

I've thought about that, but the same happens when I completely disconnect my hardware.

 

Also, with the A/T engaged, the white marker is showing the commanded N1 from the A/T, whereas the blue is showing the physical hardware position, which in this case is lower than the A/T command. If there's a spike anywhere, it's in the A/T.

 

With A/T disconnected, have you noticed how the white commanded N1 (in this case hardware commanded) first dips to the real idle and then recovers slightly to a higher value? Pressing and holding F2 accounts for the delay: press it and the commanded N1 slowly drops before reaching 'real' idle, at which point the reversers deploy. This might or might not coincide with nosewheel touchdown. Release F2 anywhere in this process, and it jumps back to the slightly higher value (stowing the reversers) before it then drops down to 'real' idle at the 'critical moment'.

 

Chad

[777simmer 117]

Chad, you inputs have given me some ideas to look at.

 

It looks to me as if the system works different depending on Autoland or Manual Land with AT engaged or Manual Land without AT.

 

Which I think is why users are getting different results and some say "works fine here" and others "I have this problem as well".

 

 

Try this guys:

An Autoland where you look only at the throttle quadrant.....dont look outside, it is not important.

 

If I do an Autoland flare mode engages at 50ft and the AT moves the Throttle Levers to idle a little later (should be around 25ft). All fine, just as is supposed to.

Now look at the thrust levers!

See how they move to idle?

 

At some point the speedbrake lever moves rear (if you armed it)....this means the main gear is now on the ground.

The nose however is still flying!

 

Now watch how as soon as the nose gear comes down the TL move further down.

 

The difference I assume is Flight idle.....before nose gear touchdown

Ground idle after nose gear touchdown.

 

The real 777 has flight idle and ground idle as well, but it has it at the same TL POSITION!!

Flight idle versus ground idle is set by the EEC at the same full back TL position depending only on ground/flight mode.

Otherwise with AT disengaged and the TL at idle.....there would not exist a flight idle mode.

The manual call it approach idle and minimum idle now (I just looked it up) and minimum idle is selected after touchdown........I interpret that as main gear touchdown....not nose!

In the PMDG777 flight idle is achieved by a higher TL POSITION.....and that is a problem.

Because I need the physical TL to be at idle to activate the thrust reversers with my hardware.

 

It is actually funny that the spoiler DO extend even though the TL are not fully back yet (because that is a requirement in addition to main gear not tilted), but the reversers cause problems?

 

 

I am not done yet with the Autoland version of this problem (still trying things and settings) but I wanted to post the above in the mean time.

 

Also, I will be looking into more things later on as I have time (Manual landing with AT, and Manual landing without AT.).

[777simmer 117]

Update: The CDU option to override AT during flare does not help during this Autoland scenario. The TL still only move to the flight idle POSITION. Even moving my hardware TL a bit and than back to idle after maingear touchdown but before nose gear touchdown does not move the PMDG TL all the way back.

 

I tried a few F1 clicks as well....same same, with or without the CDU option to override the AT during flare, I can not move the PMDG TL all the way back untill nose gear touches down.

[AlanB77L 0]

Rob,

 

I was about to report back myself regarding an autoland I've just done, same results as yours. I can press F2 as much as I want, it'll only go through idle into reverse once the T/Ls let me go further than this artificial idle position.

 

Good point about the spoilers, maybe it has something to do with the fact that the T/Ls do go to the actual idle position briefly before moving back up to a slightly higher value. You can try this in flight too: hold down F1, then release it, note how the N1 rises as the T/Ls move a tiny distance forward again.

[777simmer 117]

hold down F1, then release it, note how the N1 rises as the T/Ls move a tiny distance forward again.

The real TL do this as well sometimes.......kinda like a tiny dead zone (much smaller than the ground/flight idle difference.......but it does not allways do that though, seems to be mode dependant.

 

You often notice how the pilot flying would pull the TL back again that last 1cm (overriding the AT) only to have the AT move the TL fwd by that same distance again, lol.

Dont know what that is for.

Who knows....might really be a deadzone for a certain mode.....no idea.

I will try to pay more attention to that next time I notice that.

 

But that is not the same thing as what we see during autoland.

That is definately flight idle vs ground idle!

 

 

Ps, I did submit a ticket about the autoland reverser situation.

[777simmer 117]

Eureka......I came up with something that works (for me)...maybe it works for others as well.

This will do for me untill PMDG comes up with a fix (if there is one).

 

Requirement is:

- FSUIPC paid version, and

- throttle axis detected AND calibrated throught FSUIPC.

I know there were some problems with calibrating things via FSUIPC but I have no problems anymore now that we are at PMDG777 SP1C and I am using FSUIPC version 4.934.

 

 

Since the only way to activate the reversers without failure is by a holding down F2 after touchdown I tried to have FSUIPC send a continuous F2 command.

And it works...even after an autoland!

 

Below are 3 screen shots of FSUIPC for clarity:

 

This first one shows how I have FSUIPC detecting my throttle axis.

I have a single axis for forward thrust and reverse thrust but I decided to split the range of my thrust lever between Throttle 1 and Reverser 1 non the less.

This is not a requirement I think.

You can also only have FSUIPC detect throttle 1 and then define a range for idle thrust and reverse thrust on the calibration tab (see 2nd pic)

 

More important is the right side.

I have setup a range of my throttle axis to send a "throttle 1 decrease" command PLUS a checkmark in "command to repeat while in range"....this command does the same as holding F2.

I have a checkmark in Down because I only want this F2 command to be sent when I go from idle thrust to reverse thrust (not when I go from reverse thrust back to idle again)

 

 

 

 

In the picture below you see my hardware throttle lever range for "idle thrust - full thrust".

The full range for my TL is -16384 to +16384, but I have cut it into sections.

 

I have a checkmark in "no reverse zone" because I decided to split the fwd and reverse thrust axis range (as mentioned above).

(If you dont put a checkmark in "no reverse zone" you would see an additional button between (the min and max button) to set up an idle thrust range. You would do that (not putting a checkmark in there) if you had the FSUIPC page above setup to only detect throttle 1......without reverser 1).

 

I have a small deadzone both at idle as well as full thrust.

Example for left TL: 

- moving the TL full fwd (that would give me 16384) and then a tiny little bit back (in my case that gives me 16055)....then press the max set button.

- moving the TL to idle (with my single lever for fwd and reverse thrust this gives me 5500) and then a tiny bit fwd (in my case that gives me -5202)....then press the set min button.

 

The deadzones make sure I can allways set max and idle thrust even if those number vary a little bit (and they allways do)!

 

Then repeat for the right TL.

 

Ps you want to try to get similar numbers in the fields for left and right throttle as much as possible  so that N1 between the left and right engine is the same (in sync).

Mine are close but not perfect......for all practical purposes it works good in the simulation already but I might try and get them even closer)

 

 

 

 

Below you see how I have setup the calibration for the reverser range of my throttle axis.

 

I have not setup a deadzone for the reverser (but you can ofcourse) because it does not matter much if I get 50% N1 when I reverse or only 48%

Reverser is not an exact science unlike flying an approach ;-)

 

 

So all in all my left TL axis range looks like this:

 

Full reverse---------Idle reverse                                                                         

    -16384-------------  -9433

                               

 "throttle reduce command" range

     -8840------------------  -6038

 

 deadzone  (from-5500 to -5205)

 

idle fwd thrust                                   full fwd thrust 

   -5205-------------------------------------  +16055 

 

deadzone(up to +16384)

 

 

In Praxis:

When you close your TL upon landing, you are moving the TL within the idle deadzone......this will command idle thrust lever position.

However, the PMDG777 thrust levers will probably only move to flight idle at this point and that would prevent the thrust reverser to open.

 

Next phase is that after main gear touchdown (in a adition to the touchdown sound you will hear how the speed brake lever moves up if it was armed) you move your TL further back to within the "throttle reduce command" range (similar to F2 held down).

This will give a continuous F2 command and thust the PMDG throttles will move all the way to ground idle and then the reverse levers will raise.

(If you leave your TL here, then you will end up with full reverse thrust eventually as the F2 signal continues.)

 

After the reverse thrust levers have gone up you are waiting for the reversers to open before you continue to move you TL back.......this is the same as in the real aircraft where you have to wait for the interlock system to allow further reverse thrust lever movement :-)

 

What I do, as soon as I hear the reverser sound (and see REV has changed from amber to green) is that I move my TL further back to my reverse idle position.

That will stop the F2 signal and set reverse idle instead of full reverse :-)

I use reverse idle for allmost every landing.

 

If I want more than reverse idle then I continue to move my thrust lever aft.

 

Then when I want to reduce reverse thrust again (60kt), I move my thrust lever fwd again, and when I reach the reverse idle position again, I get reverse idle.

 

When I want to stow the reverser (taxi speed) I move my thrust levers from reverse idle to normal (fwd) idle and since I did not put a checkmark in "UP" (see first pic) the F2 signal is not given now even though I do move through the F2 (or reduce thrust command) range :-)

 

 

Of course it should be possible to make this work when you have a different axis for fwd and rev thrust as well.....Important is just that the F2 command is send for a little while (a second long or so) after touch down.

[777simmer 117]

PMDG has replied and we are investigating.......but there are only 4 tickets submitted about this problem.

 

So, either everyone here is lazy, or

Most here have fixed it allready.......please let us know how!

 

Keep you posted.

[sosuflyer 30]

I did a fresh re-install of the 777lr/f, then the -300er, then sp1c for both respectively, and followed RSR's suggestion with the gauges folder and saved panel states before the re-install. What happened was this:

 

The following landings were with the AP OFF and A/T ON.

 

First flight and first landing everything was perfect. I had A/T Idle Flare override enabled, and I pressed F1 during flare. Then when the main wheels touched, I pressed F2 once, and reverse thrust (idle) activated as it should and stayed activated through nose wheel contact and rollout.

 

However, subsequent landings have yielded a different result which others here are experiencing. I can't get the reverse thrust to activate until nose wheel touchdown now.  I have turned the Flare A/T Idle override off and then on again in case it needed to be re-activated, but it's still a no go. During the flare, eicas is showing my throttle being commanded to idle (white circumfrential line is moving) when I press F1, but the A/T is ignoring it and not reducing it to idle when I command.

 

So, in summary, after SP1C install, first landing: Perfect. All consecutive landings: Not behaving normally

 

I have tested this many times. I will send a ticket as well.

[777simmer 117]

So, in summary, after SP1C install, first landing: Perfect. All consecutive landings: Not behaving normally

 

I have tested this many times. I will send a ticket as well.

Yes please do so.

 

The more info they get the better.

 

PMDG replied to me already so we are exchanging info at the moment.

Not sure yet if the problem is at my (our) end or not.

 

I do not think it is a hardware related problem though, because I got the same behavior with my USB hardware throttle disconnected!

FSUIPC or something else is possible......we shall see.

 

In the mean time, the above setup (see pics) still work for me :-)

 

 

Thx for your reply.

[Floco777 2]

I made a simple flight, twice. Selected my home city airport, took off, flew over the city and returned to land. I used the same panel state I always use, the long flight state. Programmed the FMC (departure and destination airports, in this case the same one, fuel, payload, take off and landing rwy, etc); In the first time I landed with A/T on and A/P off. Pressed F1 at 20 feet AGL and then F2. The reverses opened as soon as the main wheels touched the ground. In the second one, I made an autoland. I pressed F1 at 20 feet AGL, then F2 and the reverses again opened as soon as the main wheels touched the ground.

But when I tried to make a flight between "A" and "B", following the same procedures described above, the reverses only worked after the nose wheels touched the ground. I also made this flight twice, first time landing with A/T on and A/P off and in the second time doing an autoland.

The only difference between the two kinds of flight was the ASNext. I didn't' use it in my two first flights, but used it the latter flights.

Can the ASNext played a role here?

[AlanB77L 0]

I found a fix which works for me (so far), so I was a little worried about the previous post about ASNext. I've just tested and can confirm my fix still works, whether or not I have ASNext enabled.

 

The fix is simply (contrary to suggestions in the Introduction document) to calibrate the throttles using FSUIPC. I had avoided doing this up to now, because of what I'd read in the PDF.

 

I'll continue testing of course and report back if that fix suddenly stops working.

[Floco777 2]

I found a fix which works for me (so far), so I was a little worried about the previous post about ASNext. I've just tested and can confirm my fix still works, whether or not I have ASNext enabled.

 

The fix is simply (contrary to suggestions in the Introduction document) to calibrate the throttles using FSUIPC. I had avoided doing this up to now, because of what I'd read in the PDF.

 

I'll continue testing of course and report back if that fix suddenly stops working.

The Asnext was just a thought. I use a joystick that was calibrated with FSX Axis, not with FSUIPC.

[777simmer 117]

I dont have ASN.....I use OPUS FSX.

 

Dont think it is related to a weather engine.

 

 

But the A----B theory is a new one and worth taking a look at in my opinion.

[PinkPony 171]

Any updates guys?

 

Leo Cal

[Floco777 2]

Well, this what I recieved from PMDG yesterday:

 

"We are looking into this issue currently but I don't know if it something that can be easily fixed for some users.  In your case,  I think the solution is actually quite simple.   Go to the FSX Key command menu and find the "Throttle Reduce Quickly = F2" command and slide the little slider on the right to the full right position (repeat on).   That way when you hold the F2 command it will continuously send the command to activate and increase the Reverse thrust."

 

The only problem is that I don't see the slide...

But in my last to flights, the reverses did work.