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ahinterl

MD-11 (FS9): Exiting takeoff mode

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I please need some explanation of the takeoff mode.My understanding that there are two "sub" modes of takeoff mode, namely the lateral and the vertical takeoff modes. The FD under normal circumstances goes to takeoff mode(s) on ground (details what requirements are to be met are in the airplane systems manual).Here I do have the first problem: I can see a lateral takeoff mode on the PFD ("TAKEOFF"), but speed and altitude annunciations are always PITCH and T/O CLAMP before initiating the takeoff roll, so I have no visual indication of any vertical takeoff mode.After takeoff, speed annunciation is still PITCH and altitude is T/O CLAMP, I can now exit the lateral takeoff mode by e.g. selecting a new heading and pulling the heading knob. Visually, this is reflected on the FMA by announcement of HEADING.Exiting the vertical takeoff mode is possible as well, e.g. by pulling the altitude knob. But below the thrust reduction altitude, there's no visual indication on the FMA that the vertical takeoff mode was cancelled if the altitude knob was pulled below thrust reduction altitude.Since I consider the vertical takeoff mode to be the one of relevance for the ATS to switch thrust limit to CLB, I wonder if it's possible to tell looking at the instruments alone whether the takeoff mode has been cancelled (and thus climb mode is armed, with an automatic engagement at thrust limit altitude) or not.Andreas

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The upcoming fix will resolve a problem of cancelling autoflight. But, I think you are asking something different.The AFS uses pitch control during climbout to maintain target speeds. Cancelling vertical mode would be equivalent to using FCP SPD instead of autoflight (if that is the question). Reduction to climb power still occurs at target altitude.You can change the altitude that climb power becomes active on the takeoff init page (if that was the question).Maybe I don't understand the question. What is it you are trying to accomplish?

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Maybe I also misunderstand but PMDG simulate the pin option, meaning you can arm NAV + PROF after engine start. This is clearly displayed in Magenta in the FMA and the modes are available above 400ftRob

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I see, I didn't express my problem clearly enough. I neglect any more precise procedures like switching to FMS speed or flaps retraction here, the example is just an example and shouldn't overcomplicate things.From what I understand, things go like this:FD is in takeoff mode while on ground (well, under normal circumstances). The announcement is: <v2-speed> PITCH | TAKEOFF | T/O CLAMP.After liftoff, the announcement changes to: <v2-speed> PITCH | HEADING <hdg> | T/O CLAMP (I'm not sure whether a change to HEADING is made, I'm currently experiencing some strange hdg values, a problem that I described in another thread; anyway, you can get HEADING by pulling the heading knob with some heading dialled in the heading window, so then HEADING should be there I guess).Both a thrust reduction and an accelereation altitude are present in the FMC on the TAKEOFF page. After liftoff with only A/T engaged, FD is still in (vertical) takeoff mode since nothing has been done to get it out of that mode. According to the manual, selecting another (vertical) mode cancels takeoff mode.Well, when looking at the annunciator (<v2-speed> PITCH | HEADING <hdg> | T/O CLAMP), the difference to what was there before takeoff is that TAKEOFF was replaced by HEADING. Since this is the roll mode part of the FMA, I can assume that roll takeoff mode is cancelled, and I can clearly see this on the different FMA annunciation.Back to the plane: FD is still in (vertical) takeoff mode and I need to get it out of that mode to allow A/T to switch to CLB thrust limit when passing the thrust reduction altitude. So, I pull the altitude selector well below thrust reduction altitude (I assume a high value is present in the altitude window). This means "level change" to the AFDS, and since it's a "new" vertical mode, it cancels (vertical) takeoff mode.What do I have on the FMA? It's still <v2-speed> PITCH | HEADING <hdg> | T/O CLAMP. Pulling the altitude knob invisibly changed the vertical mode, but I have no visual feedback that this change has happened.As soon as the thrust reduction altitude is penetrated, the thrust limit automatically switches to CLB and the FMA changes to: <v2-speed> PITCH | HEADING <hdg> | CLB THRUST. Now, I have my visual feedback, but not at the time I wanted it to appear.Hope it's more understandable now...Andreas

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I don't see a problem statement.The thrust will remain at takeoff until either you reach the climb thrust altitude or your turn off ATS (autothrottle)If you want to change to climb thrust earlier, you either set that into the T/O Init page or turn off ATS. The fact that you cancelled PROF and are now flying to whatever altitude you have set into the FCP is independent of the thrust modes in this case.

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I don't see a problem statement.The thrust will remain at takeoff until either you reach the climb thrust altitude or your turn off ATS (autothrottle)If you want to change to climb thrust earlier, you either set that into the T/O Init page or turn off ATS. The fact that you cancelled PROF and are now flying to whatever altitude you have set into the FCP is independent of the thrust modes in this case.
Quick question (And I am reading the docs and studying like I am going for a real type rating!!) is there no way to command CLB Thrust yourself with the push of a button like the 744 without selecting it in the FMC?CheersRob

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My knowledge is limited (I don't have a type rating) but I you should be able to enter a new value for the climb thrust altitidue. It will accept any number greater than something like 900-1000 agl. Usually, you don't want to throttle back lower than that. When I first started flying her I wasn't used to the climb thrust for about 3000 ft and would change those numbers everytime but I'm used to it now and heard that this is the way she is flown.

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Though I tested several times yesterday, for whatever reason (I don't ask anymore, maybe my computer is faulty) I spent some time finding out what I wanted to know and now have both a slightly different result and some more knowledge ;-)Pulling the altitude knob below thrust reduction altitude forces the thrust limit to go immediately to CLB and changes the altitude annunciation to CLB THRUST. So, I have my visual feedback, but the result of pulling the altitude knob is somehow different from what I'd expect since this action makes the concept of thrust reduction at thrust reduction altitude obsolete. On the other hand, the manual states pulling the altitude knob in climb sets CLB thrust...What I need to test still is what result I get when switching to v/s.Thank you anyway.Andreas

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The use of V/S for initial climb out is dangerous. The only time I use V/S for a climb is doing a step climb in the 744 to accomplish that task smoother than the automated step (I creep up at about 500 fpm). The primary control variable for climb is IAS and that is controlled with pitch. Using V/S for climb puts you in the uncomfortable position of allow IAS to decay to maintain climb rate or conversely climbing at a lessor rate than possible with available thrust, which is uneconomical.Why do you want to use V/S for climb?

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