CWS seems don't react like expected in this case.....

[DrumsArt 270]

Hello,In the FCOMv2 on page 221 there is :"TBC4.20.9

Pitch CWS with a CMD Engage Switch Selected

The pitch axis engages in CWS while the roll axis is in CMD when:

-a command pitch mode has not been selected or was deselected

-A/P pitch has been manually overridden with control column force. The force required for override is greater than normal CWS control column force."

and below :

"If pitch is manually overridden while in ALT HOLD at the selected altitude, ALT HOLD changes to CWS P. If control force is released within 250 feet of the selected altitude, CWS P changes to ALT ACQ, the airplane returns to the selected altitude, and ALT HOLD engages. If the elevator force is held until more than 250 feet from the selected altitude, pitch remains in CWS P."

So, seems it don't work for me for the second condition. If I override with control column force at selected altitude this is what happens :

-ALTHOLD changes to CWS P>>>>OK for me but :

-The plane don't quit the selected altitude anyway. If I increase the force then autopilot just disconnect and fails !

Please can anyone try that ?

Win XP pro SP3, FSX SP2 Acceleration + Saitek Flight Yoke (correctly calibred) + Ezdoc

Thank you in advance

Regards,

Richard Portier

[Cras 6]

Yes, when I saw that in the manual I tried it as well, and saw the same issue, it did not kick back over to ALT HOLD.

[DrumsArt 270]

Hi Scott, Do you know if PMDG have knowledge of that ? If not I will submit a ticket... Regards, Richard Portier

[badderjet 181]

Yes, I've just as well come across conditions regarding CWS where the AFDS wouldn't maintain any of the parameters but wouldn't allow manual control either (joystick virtually non existent until complete AFDS disconnection).

[VIPERGTSR01 22]

I tried this today while in a holding pattern, I put a lot of deflection on my flight stick and it went into CWS P, I quickly let go and it went away back into holding ALT, worked great. I did the same with roll and it went into CWS R but I was then stuck with CWS R and doesn't matter what I did I couldn't get it back to LNAV CMD (still stayed in Alt hold though). It did give me time to try CWS R and it was very easy to use and felt like cheating :(

[DrumsArt 270]

I tried this today while in a holding pattern, I put a lot of deflection on my flight stick and it went into CWS P, I quickly let go and it went away back into holding ALT, worked great.

The question is : do your altitude has changed when you was in CWS P ? If not, so, it don't work like expected."If pitch is manually overridden while in ALT HOLD at the selected altitude, ALT HOLD changes to CWS P. If control force is released within 250 feet of the selected altitude, CWS P changes to ALT ACQ, the airplane returns to the selected altitude, and ALT HOLD engages. If the elevator force is held until more than 250 feet from the selected altitude, pitch remains in CWS P." Regards, Richard Portier

[VIPERGTSR01 22]

The question is : do your altitude has changed when you was in CWS P ? If not, so, it don't work like expected."If pitch is manually overridden while in ALT HOLD at the selected altitude, ALT HOLD changes to CWS P. If control force is released within 250 feet of the selected altitude, CWS P changes to ALT ACQ, the airplane returns to the selected altitude, and ALT HOLD engages. If the elevator force is held until more than 250 feet from the selected altitude, pitch remains in CWS P." Regards, Richard Portier

I can't remember how much alt I changed, I will give it another whirl later. So you're saying it does go into CWS P however when it passes 250ft from selected alt it just disconnects rather than remaining in CWS P?

[DrumsArt 270]

I can't remember how much alt I changed, I will give it another whirl later. So you're saying it does go into CWS P however when it passes 250ft from selected alt it just disconnects rather than remaining in CWS P?

No, I say :-ALTHOLD changes to CWS P>>>>OK for me but :-The plane don't quit the selected altitude anyway. If I increase the force then autopilot just disconnect and fails ! (see my first post above)Regards, Richard Portier

[VIPERGTSR01 22]

No, I say :-ALTHOLD changes to CWS P>>>>OK for me but :-The plane don't quit the selected altitude anyway. If I increase the force then autopilot just disconnect and fails ! (see my first post above)Regards, Richard Portier

Alright I will see if it if it changes alt then.

[VIPERGTSR01 22]

Ok I did it again, took off and went into a PPOS hold (so I can fiddle with things and return quickly when I want). Once again I pulled back on the stick and got CWS P, I let go after about 100ft gain and it goes back into to ALT hold. I then try again this time holding it longer, it went into CWS P and I continued to climb from 3000ft to 4000ft and it stayed in CWS P then I descended back to 3000 and it returned to ALT HLD again perfectly. I will mention since last time I had added the hot fix so you might want to try again with it installed, never know whats really changed in there (is it just me or have they added more taxi tyre sounds?), oh and it did fix my panel freeze problem, thanks PMDG team :)

[badderjet 181]

The question is : do your altitude has changed when you was in CWS P ? If not, so, it don't work like expected."If pitch is manually overridden while in ALT HOLD at the selected altitude, ALT HOLD changes to CWS P. If control force is released within 250 feet of the selected altitude, CWS P changes to ALT ACQ, the airplane returns to the selected altitude, and ALT HOLD engages. If the elevator force is held until more than 250 feet from the selected altitude, pitch remains in CWS P." Regards,

Ok disregard, it almost works as expected as far as I can tell. Overriding works and puts pitch into CWS P (SLOWLY as you might break the FCC otherwise). Releasing force or not maintaining enough will trigger ALT ACQ within 250, but sometimes also less than that (?), probably depending on closure rate?? What IS strange though, is the "mode changed" annunciation without any mode. I've seen this under other circumstances as well (engage CWS without any AFDS modes and with FDs off and watch the FMA): EDIT Hm the 250 ft limit only seems to apply to when you're already within that limit. If you approach the select altitude from outside ±250, ALT ACQ will come on at significantly less than 250. Maybe this is sitll as it should be though, need to read on here.

It did give me time to try CWS R and it was very easy to use and felt like cheating

Yeah huh just like a 'bus. There goes the fun. EDIT 2 Follow up obersavtions for those who have too much time to try.Initial conditions: Fly at some altitude, preferably MCP SPD, HDG SEL, ALT HOLD. I will suggest 250 knots and 10000 feet so we're on the same page here. Scenario 1:- Override pitch with control column and go into CWS P, maintain positive pressure. You might need to apply significant force unfortunately, eventually yielding high V/S initially. It's only important to make sure it doesn't go back to ALT HOLD within the first 250 feet.- Establish steady climb/descent, aim for something like 1000 fpm to be comfortable.- Reset MCP altitude to something you would reach in like 1000-2000 feet. Say you started the maneuver at 10000, and then started a CWS P climb, maybe go for 13000 or so- Watch CWS P exstinguish and ALT ACQ engage just as you hit 13000. Scenario 2:- Say we're at 10000 in ALT HOLD. Select say 13000 on the MCP. V/S will arm.- Override pitch just as described above, make sure you're in CWS P- Establish climb, see above- Approaching 13000, watch how nothing happens on the pitch channel, quite contrary to the above, and without manually intervening you'll shoot right through it. I have to say I haven't digged deep into CWS so far, but is this as it should be? Would be interesting to know, as DURING the CWS climb, the (pitch) conditions seem to be perfectly the same - CWS P and no climb mode armed or selected, obviously. Only that ALT ACQ would engage in the one case (no V/S armed before, MCP altitude reset DURING climb) but not in the other (V/S armed before, MCP altitude reset BEFORE climb).

[DrumsArt 270]

EDIT 2 Follow up obersavtions for those who have too much time to try.Initial conditions: Fly at some altitude, preferably MCP SPD, HDG SEL, ALT HOLD. I will suggest 250 knots and 10000 feet so we're on the same page here. Scenario 1:- Override pitch with control column and go into CWS P, maintain positive pressure. You might need to apply significant force unfortunately, eventually yielding high V/S initially. It's only important to make sure it doesn't go back to ALT HOLD within the first 250 feet.- Establish steady climb/descent, aim for something like 1000 fpm to be comfortable.- Reset MCP altitude to something you would reach in like 1000-2000 feet. Say you started the maneuver at 10000, and then started a CWS P climb, maybe go for 13000 or so- Watch CWS P exstinguish and ALT ACQ engage just as you hit 13000. Scenario 2:- Say we're at 10000 in ALT HOLD. Select say 13000 on the MCP. V/S will arm.- Override pitch just as described above, make sure you're in CWS P- Establish climb, see above- Approaching 13000, watch how nothing happens on the pitch channel, quite contrary to the above, and without manually intervening you'll shoot right through it. I have to say I haven't digged deep into CWS so far, but is this as it should be? Would be interesting to know, as DURING the CWS climb, the (pitch) conditions seem to be perfectly the same - CWS P and no climb mode armed or selected, obviously. Only that ALT ACQ would engage in the one case (no V/S armed before, MCP altitude reset DURING climb) but not in the other (V/S armed before, MCP altitude reset BEFORE climb).

Thank you for your answer So, Scenario 1 :I tested again but the problem is it don't work for me... I have the CWS P but the altitude don't change, it stays at 10000 fts. If I increase pressure (gently), the A/P goes off and fails. Is it harware problem ? My Saitek Flight Yoke sensibility tuned full on the right. Scenario 2 :I have the same result that you describe.But if I press V/S>>> MCP SPD, HDG SEL, VSPEED>>> I override pitch positive or negative, the CWS P mode engages and altitude changes, CWS P exstinguish and ALT ACQ engage when I hit the selected altitude (it's the only way I found to work). Any idea about the problem ? Am I alone with that ? Regards, Richard Portier

[badderjet 181]

So, Scenario 1 :I tested again but the problem is it don't work for me... I have the CWS P but the altitude don't change, it stays at 10000 fts. If I increase pressure (gently), the A/P goes off and fails. Is it harware problem ? My Saitek Flight Yoke sensibility tuned full on the right. Scenario 2 :I have the same result that you describe.But if I press V/S>>> MCP SPD, HDG SEL, VSPEED>>> I override pitch positive or negative, the CWS P mode engage and altitude change. Any idea about the problem ? Regards, Richard Portier

Hey, sorry, but I digressed. My post wasn't actually referring to your problem exactly, TBH. It was more about the differences of ALT ACQ/ALT HOLD engaging on its own or not and under what conditions. If anyone still would like to try the above I'd certainly appreciate it. As to your problem I can only say I believe I've had not the exact same thing already, but slightly different. Basically CWS P was active, which should have allowed manual control, but the AP didn't "allow" joystick inputs, they were completely ignored. HOWEVER, the AP would also NOT maintain the altitude (I believe this is the difference to yours). So basically it was a situation with random outcome. Will have to dig into it again in order to find steps to reproduce, this seems to be the hardest with this add-on all the time I have to say. Not so many "stable" and simple bugs haha, at least it seems so... On another not-so related note, I really think the CWS could need some fine tuning. It might be me or my hardware (MS SideWinder FF2), but disengaging ALT HOLD by overpowering will result in rapid pitch change, gross pitch attitudes and vertical speeds as long as you TRY to maintain CWS and not let it revert to ALT HOLD. The control "angle" (I mean the hardware control angle) that is required to maintain CWS is just very large methinks. I'd rather have the "null zone" that would trigger ALT HOLD quite a bit tighter around the center. But that's just my very own impression of it.

[DrumsArt 270]

Hey, sorry, but I digressed. My post wasn't actually referring to your problem exactly, TBH. It was more about the differences of ALT ACQ/ALT HOLD engaging on its own or not and under what conditions. If anyone still would like to try the above I'd certainly appreciate it. As to your problem I can only say I believe I've had not the exact same thing already, but slightly different. Basically CWS P was active, which should have allowed manual control, but the AP didn't "allow" joystick inputs, they were completely ignored. HOWEVER, the AP would also NOT maintain the altitude (I believe this is the difference to yours). So basically it was a situation with random outcome. Will have to dig into it again in order to find steps to reproduce, this seems to be the hardest with this add-on all the time I have to say. Not so many "stable" and simple bugs haha, at least it seems so... On another not-so related note, I really think the CWS could need some fine tuning. It might be me or my hardware (MS SideWinder FF2), but disengaging ALT HOLD by overpowering will result in rapid pitch change, gross pitch attitudes and vertical speeds as long as you TRY to maintain CWS and not let it revert to ALT HOLD. The control "angle" (I mean the hardware control angle) that is required to maintain CWS is just very large methinks. I'd rather have the "null zone" that would trigger ALT HOLD quite a bit tighter around the center. But that's just my very own impression of it.

So back to square one Regards, Richard Portier

[Cras 6]

After doing some searching on the internet, I found one real line pilot of the 737 say that when he uses CWS on the real plane, he activates it not by applying pressure to the stick, which is how I first tested it in the NGX and got the same excessive V/S, but rather turns off the appropriate mode on the MCP. So If his plane is in HDG SEL mode, and wants to activate CWS R, he pressed the HDG SEL button on the MCP to kill the roll mode, and the AP will fall back into CWS. Then make the change. I have done this with CWR R mode, and was able to arm VOR/LOC, which activated properly as one would expect it too. Very cool. I tried this method with CWS P mode. I turned off in my case VNAV, and the autoflight fell back into CWS P mode. I altered the altitude in the MCP, pulled up on the stick to get a nice 1500 v/s and ALT ACQ never armed or activated, Instead the plane broke the altitude restrction. This is where I think something is amiss, and obviously the inability to control the plane in any fashion when CWS is armed directly on the MCP. CWS seems to work fine when CMD is armed but no roll or pitch mode is activated, but not the direct CWS button. I will try the two scenarios you posted shortly and will report what I find. Cheers,