retard in "white" autopilot mode

[Guest meirumeiru]

I'm flying often with the FMS commanded speed during the whole flight (so, in the "magenta" mode, if you wan't to call it like that) ... in this mode, the AP is retarding at 35 feets over ground... an other solution is to disable ATS at about 100 feets and fly manually from there... now, want I don't understand is, if the AP commands the retard also, if it flyes in the what I call "white" mode... so, if you set the speed by pulling the speed selector knob... should/does it retard or not?

[mburkhard 23]

I'm flying often with the FMS commanded speed during the whole flight (so, in the "magenta" mode, if you wan't to call it like that) ... in this mode, the AP is retarding at 35 feets over ground... an other solution is to disable ATS at about 100 feets and fly manually from there... now, want I don't understand is, if the AP commands the retard also, if it flyes in the what I call "white" mode... so, if you set the speed by pulling the speed selector knob... should/does it retard or not?

Rudolf,ATS will always retard the throttles if engaged during landing. And the RETARD label on the FMA will always be white, since the retard command is not coming from the FMS.Regards,Markus

[Turbine777 13]

When I 1st read this topic I was wearing white sweats and a white T-shirt. So basically that you were making fun of me :(

[Guest meirumeiru]

Rudolf,ATS will always retard the throttles if engaged during landing. And the RETARD label on the FMA will always be white, since the retard command is not coming from the FMS.Regards,Markus

Ok, I made a test. I took the MD-11 to LSZH (runway 16) and flew once around the airport. Then I laded again at runway 16. I entered LSZH/LSZH as the route, altitude of 100, ci of 50 then the whole infos for takeoff (to calculate the v1, vr and v2). Finally I had a good config (green bar). After takeoff I turned left (manually, then activated the AP by pressing the "autoflight" button). After, I selected the speed (250) and the heading (about north). The altitude was set to 6000.Then, north of the airport I turned left (manually, so, I pressed the yellow button on the yoke and turned left) ... I still had the ATS activated at this time... then I selected 156 for the speed and slowed down when I found the glideslope and started descending.I didn't extend the flaps fast enough, so the autopilot did set the speed to 172 and I corrected this by setting it to 156 again (this time with flaps and gear extended) ... so, everything seemed to be fine. (ATS on, rest manual). Then I waited what would happen... I expected, that the autopilot would command the retarding at 35 feet above ground... 100, 50, 40, 30 ... and so on... I started to flare, but the retarding never happened and so I ended flying along the whole runway at about 15-25 feets above ground... then, I disengaged the ATS manually and retarded manually to land the plane (of course, this was almost at the end of the runway and I had to go around) ... and, that's what I don't understand... shouldn't the autopilot command a retard in this situation? ... when I fly from one point to an other and let the FMS set the speed during the whole flight, I don't have that problem... I think, I also don't have it, if the FMS commanded the speed in the beginning and I switch to manual mode in the end (not always, but I can't say when it happens, that the retard isn't commanded) ... I think, the last time I had this problem was, when the FMS suddendly lost the "CRZ" entry and stopped commanding any speed...so... is this because of me? my pc? or... is this by design? ... a bug? ... would be nice to read more about thatRudolf

[aentwis 61]

As Markus wrote, regardless of whether you are in FMS mode or selected mode for speed, the ATS, when active, will retard the throttles on landing, around 35'RA...It is a good idea to move your controller's thrust lever to its idle position, to guarantee that the controller does not send a signal and interrupt the retard...You were flying an autopilot controlled approach or manually?If you perform an autoland with ATS in selected speed (the way I tend to land if I am in IFR/CATIII and cannot see the runway until decision height, otherwise, I throw off the AP at 1000'RA and fly in manually, sometimes with ATS active, sometimes not), then the ATS always retards the thrust at around 35RA... I cannot see what you may be doing wrong from your description. Perhaps you should take some screenshots to illustrate your problem and post them. If you do, make sure that the necessary elements on the displays are visible...A bug in this system would have been found by a number of users a long time ago, myself included. The MD11 is one of my personal FS hangar favourites, and I am sure I would have found a problem here if there was one...Andrew

[Guest meirumeiru]

As Markus wrote, regardless of whether you are in FMS mode or selected mode for speed, the ATS, when active, will retard the throttles on landing, around 35'RA...

that's what I understood now... but it didn't retard... now I'd like to find out why

It is a good idea to move your controller's thrust lever to its idle position, to guarantee that the controller does not send a signal and interrupt the retard...

I had the same idea and did that.

You were flying an autopilot controlled approach or manually?

At about 5000 feet i pressed the yellow button on the steering wheel to disengage the autopilot. But the ATS remained active. From then I flew manually. I never was in the "auto-land" mode or something...

If you perform an autoland with ATS in selected speed (the way I tend to land if I am in IFR/CATIII and cannot see the runway until decision height, otherwise, I throw off the AP at 1000'RA and fly in manually, sometimes with ATS active, sometimes not), then the ATS always retards the thrust at around 35RA... I cannot see what you may be doing wrong from your description. Perhaps you should take some screenshots to illustrate your problem and post them. If you do, make sure that the necessary elements on the displays are visible...

Ok, what are those necessary elements? The PFD?

A bug in this system would have been found by a number of users a long time ago, myself included. The MD11 is one of my personal FS hangar favourites, and I am sure I would have found a problem here if there was one...

Well, the MD-11 is also my favorite... that's clear. But what you say about the bug... you know, I'm software engineer and one thing I learned is, that I always find bugs in software, even if thousands say, that there are none. Strangely they always show up, when I use the software... or, maybe I'm the only one to remark that there is a bug?? ... anyway... this time, I'm able to reproduce the behaviour... again and again and again... so, I can easily make those screenshots ...so... what should I do? post the PFD? ... do you need other things? ... or, should I note every single point (every click I did) so that someone can try to reproduce it on an other computer?

[Guest meirumeiru]

you can say what you want... but the retard never happens, if I don't fly from x to y (and enter that in the FMS) ... I flew an other two times around the airport... this time I activated the autoland and waited, until it went into the "dual land" mode... then I disengaged it (ATS still working) and landed... nothing... no retard...and, other problem... because the system started shifting the CG out of limmits (drained tank 2 and filled 1 and 3), I switched to the manual mode and wanted to open the fill valve 2... no chance... it didn't open... when I clicked on the button (virtual cockpit), it opened, and when I let the left mouse button go, it closed again... but, when I had the "mouse down" over the button and the "mouse up" outside, it remained active...I wouldn't say, that this is because of the MD-11 ... could also be because of the FSX, that this happens... but these little bugs don't make me happy... I don't want to work around problems... I want to play... :)Isn't there a debug version, to analyse this behaviour?

[jeffarmy771 2]

When I 1st read this topic I was wearing white sweats and a white T-shirt. So basically that you were making fun of me :(

Thats what you get for wearing white after labor day....:(....:(

[Paul_Smith 92]

What is it that you are trying to acheive? For the ATS to engage retard automatically, a number of conditions must all be met but it sounds like you are not attempting to meet them. Why not just post a screen shot of the 2D panel from just before and just after you expect retard to be engaged and then we can see if you are suffering a PEBKAC episode.

[Guest meirumeiru]

What is it that you are trying to acheive? For the ATS to engage retard automatically, a number of conditions must all be met but it sounds like you are not attempting to meet them. Why not just post a screen shot of the 2D panel from just before and just after you expect retard to be engaged and then we can see if you are suffering a PEBKAC episode.

ok, I'll do that... you will get the screenshot tomorrow...

[aentwis 61]

Have you done any preflight whatsoever?With no preflight of weights and so on, you will have no programmed landing weight, and so no programmed landing speed...Guessing, as I haven't been in the MD11 for a few days...Andrew

[FLEX1978 373]

Have you done any preflight whatsoever?With no preflight of weights and so on, you will have no programmed landing weight, and so no programmed landing speed...Guessing, as I haven't been in the MD11 for a few days...Andrew

Andrew, he has pointed out many times that he uses managed speed without problems so it's safe to say his preflight is correct.

[Guest meirumeiru]

well, you mentioned, that the LW has to be calculated... when you only enter something like WMKK/WMKK, you don't get a real route, and then the FMS does not calculate the LW (but since I've been told, that the FMS has nothing to do with the retard function of the ATS, I thougt, that I don't have to look at this)... anyway, I tryed it... I flew the first flight without LW, and the second with LW (I entered a route around a waypoint and returned to the airport, so that the FMS did calculate a trip time and also a LW) ... but... it still does not retard. You can see this on both screenshots... I'm flying below 35 feets (this was some kind of "controlled flight into terrain" what I tryed here) and it's still in the "thrust" mode...

[Paul_Smith 92]

My first thought is that you are not landing, you are just flying into the ground. Looking at the FCOM "before landing procedure", you should slow to Vref + 5 while still above 50ft AGL, you still have 152 dialed into the FMS. Try the same landing again, but this time dial in 142 instead of 152 and see what happens.

[FLEX1978 373]

My first thought is that you are not landing, you are just flying into the ground. Looking at the FCOM "before landing procedure", you should slow to Vref + 5 while still above 50ft AGL, you still have 152 dialed into the FMS. Try the same landing again, but this time dial in 142 instead of 152 and see what happens.

Been a few months since I've flown the MD11 but something doesn't look right on the FMA, it does look like he's flying the aircraft into the ground rather then landing. Also the Vapp shouldn't matter even in selected, High elevation & Heavy you can be landing at 170+ knots