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Check_Airman

MD11 flap and climb speeds

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I was in my mess around mode when I discovered the following...When F28 is selected, raising the gear causes the F50 bug to be displayed on the speedtape, and lowering the gear causes the F35 bug. What's the display logic?If in landing config (gear +F35/50) causes the Vmo to decrease? Why is this? With F35, raising the gear causes the Vmo to decrease to ~187kt, and the F50 limit bug moves to ~157kt.If we select F50, the Vmo moves down to 157kt.Why does this happen? Is there some sort of high speed buffet associated with gear position with F35/F50? This does not happen with other flap settings. FWIW, a route was in the FMS, but no approach had been selected.On an unrelated note...Why is it that selecting a cost index of 999 causes the FMS to command the amber foot as the climb speed? Is it trying to get to crz alt as fast as possible? If so, MAX CLB in the FMS was ~230kt. Whouldn't the target speed be somewhere in this region too? Beyond a CI of ~400 the target climb speed decreases gradually to 37kt. What exactly is the FMS trying to do?I've also noticed that when the ECON climb speed is under 250kt as above, the FMC still commands 250kt until 10,000. I would have thought that the ECON speed would be the target speed.Looking forward to what those in the know have to say about this great aircraft. The logic doesn't follow the more familiar Boeing models, and it's a joy to try and wrap my head around a new design.

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Check.....(u forgot to sign again), you have got to cut it out now, you've gone too far....i keep telling you to stop faffing about and just enjoy the plane! :(

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Check.....(u forgot to sign again), you have got to cut it out now, you've gone too far....i keep telling you to stop faffing about and just enjoy the plane! :(
I consider questions like the one from "Check Airman" very valuable and interesting.Look, PMDG built a very comprehensive and complete MD-11 simulation for us to enjoy. Unfortunately (I'm sure many people don't agree here), my personal opinion is that the manuals and documents that PMDG can provide contain way too less information to understand the plane.The situation is that there's (almost) no information about the inner workings of the MD-11 systems available (I can only hope for some special guy to put training stuff onto torrent sites). On the other hand, PMDG has the knowledge since they modelled the plane accordingly. So, we all see and experience things on the MD-11 that are neither described nor explained somewhere. I for my part wish an expansion and enhancement of PMDG's Wiki to contain background information written by individuals who know the plane.I think there has been nothing in the FS scene like PMDG's bird before, and I guess PMDG set a brand new standard for plane add-ons, something that many will recognize only after using the MD-11 for some time. This also means that a much higher level of information is needed to get familiar with the plane. Manuals alone (especially the version where PMDG needed to cut things out because of copyright or legal reasons) aren't sufficient anymore, we need additional training documents IMHO. And these can only be provided by people who know the plane, and PMDG who had access to these kind of informations.One can never learn enough about the MD-11, I think. Ever little piece is important. So, I vote for some training system (as said, the Wiki is a good idea I think) for the MD-11 which contains background informations such as e.g. the methods the FMC uses to calculate target speeds, how fuel is designed to be pumped around to achieve what CG goal, how hydraulic pumps look like in real life, where the power lines are situated in the plane, for what reason there's such a small horizontal stabilizer and what that means for aerodynamics and what the engineers thought when designing it etc. etc. just to name a few of countless examples.Such a Wiki could evolve to a comprehensive study guide, offering information which can't be found in any manual as well.I for my part try to understand how the bird works step by step, and I currently cannot even explain what happens at certain fuel fill levels when I define ballast fuel for one of the tanks that can hold it - fuel is pumped around even on ground, and I lack the knowledge why the automatics do that because I don't have the information what the goals of the fuel system are. If I'm now required for instance to manage fuel flow from takeoff to landing I couldn't properly do that, I don't have any tables where the CG should be during flight and so on.The more people ask interesting questions like the above, the more we all can learn I think. Only flying the bird in automatic modes cannot be all, the MD-11 has much more to offer...Andreas

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I was in my mess around mode when I discovered the following...Why does this happen? Is there some sort of high speed buffet associated with gear position with F35/F50? This does not happen with other flap settings. FWIW, a route was in the FMS, but no approach had been selected.On an unrelated note...Why is it that selecting a cost index of 999 causes the FMS to command the amber foot as the climb speed?
Check--Obviously the "mess around mode" is not programmed to it's full extend. Can't find a reason why the indications should be presented as shown in the pictures however. CI999:May this thread give you some further info:http://forums1.avsim.net/index.php?showtopic=241471Regards,Harry

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Thanks for the link KCA,I'll draw from experience I have from other aircraft. Doing so may be dangerous, so have pitty on my mortal soul if I make a fool of myself. Here goes...The CI defines the fuel/time ratio for the flight. At higher CI, airspeed is maximized in all phases of flight to decrease the trip time. The time to crz is longer, and the trip fuel is greater. At a low CI, all speeds are slower including the climb speed because the plane tries to climb at Vy in order to reach crz altitude faster. The faster you get to crz altitude, the less fuel you burn. In most instances, the ECON climb speed will be a bit more than Vy for midrange CI's (~100).Andreas,The lack of information in the manual is not unique to PMDG. Theirs is very close to the RW manual. Over the years, the manuals have been shrunk, and it's not uncommon to hear RW guys having to go to the maintenance department to get information because the manual is not as detailed as they'd like. Blame it on the litigious society that wants to sue for the slightest of things.Paul

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I consider questions like the one from "Check Airman" very valuable and interesting.Look, PMDG built a very comprehensive and complete MD-11 simulation for us to enjoy. Unfortunately (I'm sure many people don't agree here), my personal opinion is that the manuals and documents that PMDG can provide contain way too less information to understand the plane.The situation is that there's (almost) no information about the inner workings of the MD-11 systems available (I can only hope for some special guy to put training stuff onto torrent sites). On the other hand, PMDG has the knowledge since they modelled the plane accordingly. So, we all see and experience things on the MD-11 that are neither described nor explained somewhere. I for my part wish an expansion and enhancement of PMDG's Wiki to contain background information written by individuals who know the plane.I think there has been nothing in the FS scene like PMDG's bird before, and I guess PMDG set a brand new standard for plane add-ons, something that many will recognize only after using the MD-11 for some time. This also means that a much higher level of information is needed to get familiar with the plane. Manuals alone (especially the version where PMDG needed to cut things out because of copyright or legal reasons) aren't sufficient anymore, we need additional training documents IMHO. And these can only be provided by people who know the plane, and PMDG who had access to these kind of informations. One can never learn enough about the MD-11, I think. Ever little piece is important. So, I vote for some training system (as said, the Wiki is a good idea I think) for the MD-11 which contains background informations such as e.g. the methods the FMC uses to calculate target speeds, how fuel is designed to be pumped around to achieve what CG goal, how hydraulic pumps look like in real life, where the power lines are situated in the plane, for what reason there's such a small horizontal stabilizer and what that means for aerodynamics and what the engineers thought when designing it etc. etc. just to name a few of countless examples.Such a Wiki could evolve to a comprehensive study guide, offering information which can't be found in any manual as well.I for my part try to understand how the bird works step by step, and I currently cannot even explain what happens at certain fuel fill levels when I define ballast fuel for one of the tanks that can hold it - fuel is pumped around even on ground, and I lack the knowledge why the automatics do that because I don't have the information what the goals of the fuel system are. If I'm now required for instance to manage fuel flow from takeoff to landing I couldn't properly do that, I don't have any tables where the CG should be during flight and so on.The more people ask interesting questions like the above, the more we all can learn I think. Only flying the bird in automatic modes cannot be all, the MD-11 has much more to offer...Andreas
I would kindly like to disagree with you on. I am not going to dig into the manual this late, therefore it wont't be much help to the OP. However 99% of everything you need\want to know is in the FCOM or Sys/FMC guide. It's all about knowing WHERE to look. I ordered the complete manual set and can tell you that these manuals are pretty close to the real thing. There is a COMPLETE training guide in the FCOM from cold and dark to shutting everything down. Just need to know where to look.Regards,Shawn FittsEdit- I just picked up the manuals. FCOM page NP.0.00.1 starts the process from bringing the aircraft from a cold and dark stance to shutting the BAT off after parking. Its all right there in terms of a training guide. The systems/fmc manual is slammed full of all the system data you could ever need and more. It all about knowing where to find the information.

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I would kindly like to disagree with you on. I am not going to dig into the manual this late, therefore it wont't be much help to the OP. However 99% of everything you need\want to know is in the FCOM or Sys/FMC guide. It's all about knowing WHERE to look. I ordered the complete manual set and can tell you that these manuals are pretty close to the real thing.
I know. I also know that many real world manuals aren't that perfect either. That's why I ask for some training guides.
There is a COMPLETE training guide in the FCOM from cold and dark to shutting everything down. Just need to know where to look.
Agreed, but that's not the point. Following some procedure guides is one thing, understanding the inner workings another. Understanding a system for me is key to being able to master the plane, stupid stepping through procedures just because the manual says so and never asking "why" and getting an appropriate answer for my taste is not enough. It's like "In successfully drive my car, but I don't even know a motor is needed to make it going, and I don't care. All I need to know is when to shift the gear, but I have absolutely no clue what happens technically when I do so".Anyway, I hope I can get hold of some more material for the MD-11 one day. Maybe I'm the only one with this kind of problems...Andreas

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I would kindly like to disagree with you on. I am not going to dig into the manual this late, therefore it wont't be much help to the OP. However 99% of everything you need\want to know is in the FCOM or Sys/FMC guide.
Agreed. 99% of all questions can be answered by spending some time with the FCOMs. The troublesome part is that last 1%. There is a lot of information that does not appear in the FCOM, partly because pilots would have to carry a whole other flight bag just for manuals. It's that 1% that I post here- after I've looked through the manuals.Paul

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Agreed. 99% of all questions can be answered by spending some time with the FCOMs. The troublesome part is that last 1%. There is a lot of information that does not appear in the FCOM, partly because pilots would have to carry a whole other flight bag just for manuals. It's that 1% that I post here- after I've looked through the manuals.
This brings the following two questions:1. Does this set of manuals contain the whole knowledge necessary to get type rating/captain on the MD-11?2. Do they contain enough information for PMDG to write their software?I am sure the answer to (2) is negative, (1) could also be negative.

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This brings the following two questions:1. Does this set of manuals contain the whole knowledge necessary to get type rating/captain on the MD-11?2. Do they contain enough information for PMDG to write their software?I am sure the answer to (2) is negative, (1) could also be negative.
I concur.Paul

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