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747-400 pmdg vnav altitude error?

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Hi, i loaded a plan in fsnav then saved it as a rte or might of been rt2 file. Loaded it into the FMC, set the cruising alt etc but after i take off i press the LNAV and VNAV button, course settings work and i move towards the destination airport, problem is the altitude isnt working. Ive set the crusing alt to 30,000 feet and looked at the altitudes on the RTE pages. I have to set the altitude myself, i set it to 12,000, then pressed the VNAV button again, it stayed at 12,000 and on the RTE the altitudes of the various waypoints were DECREASING on their own from FL30 (30,000 Feet) and lowering themselves until the waypoint was passed, then it happened to the other waypoints, why isnt the VNAV controlling the altittude? It says VNAV ALT on the primary flight display. When i tried to change them back to ANY altitude it just said Unable crz alt or something like that, now i can select LNAV because it says something about intercept heading is now incorrect, so i'll have to start the flight again, which as you can guess is very annoying.Another problem is the TCAS isnt working. Ive changed the knob to TA on the radio panel but no planes show up, even changed the settings to show all traffic and it still doesnt work. Thats my secondary concern, i feel the altitude problem is far more serious, any ideas on why this is happening?Thanks.

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re your TCAS problem : u need to have the trafficinfo.dll installed to show up traffic

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In regards to your TCAS.Are you pressing the ND range selector knob located on your EFIS-MCP? It has letters TFC on it.Michael

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and ehm where did u set the 12000 feet? I hope in the MCP window and NOT in the legs page cuz what you set there are only CONSTRAINS. The actual altitude Vnav is going to level off at is the value set in the MCP altitude window. Set your altitude and PRESS the altitude selector knobb ( NOT the altitude hold knobb!!!). Vnav will climb to set altitude and level off at it

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Tcas is now functional, i didnt press the button but now i have it works fine. Yes the 12,000 feet was set by me manually in the Autopilot, so to land i have to set the altitiude at 0 and hope for the best? The FMC is supposed to progeam and control the AP to climb, cruise and land itself which is what i meant meaning it wasnt working.

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>Ive set the crusing alt to 30,000 feet and looked at the altitudes >on the RTE pages. I have to set the altitude myself, i set it to>12,000, then pressed the VNAV button again, it stayed at>12,000 and on the RTE the altitudes of the various waypoints>were DECREASING on their own from FL30 > (30,000 Feet) and lowering themselves until the waypoint was>passed, then it happened to the other waypoints, why isnt the>VNAV controlling the altittude? It says VNAV ALT on the>primary flight display.VNAV is overridden with an altitude in the MCP. In your example, you set the MCP alt to 12,000 (hence the "VNAV ALT" annunciation on the FMA). Your aircraft is still VNAV armed, but will not climb to the requested 30,000 if the MCP is set to 12,000. You need to set the MCP to 30,000 and press the white knob to command the VNAV climb.Additionally, your description of descending alititudes at your fixes means that the aircraft can not get to the requested altitude before the descent profile (T/D) begins. Is your aircraft's current position within 100nm of the destination? If so, that will explain the descending altitudes. The other explaination could be an altitude restriction at a fix that is commanding a descent.VNAV isn't a "set and forget" system. It is only a workload reduction system that, at times, actually gives you additional workload. VNAV, by default, is in PATH mode. VNAV will climb (and descend) on a path based on the speed commanded on the VNAV pages. You can "intervene" by pressing the white IAS/MACH speed knob and manually set the climb/descent speed. However, bear in mind that changing the speed mid climb/descent can significantly change the profile, bringing you above/below your intended path. VNAV can only climb/descend in one of two modes; PATH or SPEED, not both.

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Hi, once again the plane flew above the airport. How do i program the FMC to land the plane? A message kept comming up saying need DRAG whilst in flight if that has anything to do with it? I went on the APP page for the airport i was landing at, EGCC which is Manchester in the UK. But nothing happened the plane didnt descend and it flew over the runway, even worse it didnt climb to do a go around and ended up crashing, why is it soo complicated to use? TBH its been more trouble than worth or enjoyment, also how are pilots meant to enter each waypoint themselfs? isnt there a auto-route option like in FSnav? Just wondering why the plane doesnt land itself, unless im doing something wrong, the plans i use are exported from FSnav. The heading is fine its just the altitudes the FMC gets wrong.Thanks for your patience, i think mine is running out lol.

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>Hi, once again the plane flew above the airport. How do i>program the FMC to land the plane? A message kept comming up>saying need DRAG whilst in flight if that has anything to do>with it? I went on the APP page for the airport i was landing>at, EGCC which is Manchester in the UK. But nothing happened>the plane didnt descend and it flew over the runway, even>worse it didnt climb to do a go around and ended up crashing,>why is it soo complicated to use? TBH its been more trouble>than worth or enjoyment, also how are pilots meant to enter>each waypoint themselfs? isnt there a auto-route option like>in FSnav? Just wondering why the plane doesnt land itself,>unless im doing something wrong, the plans i use are exported>from FSnav. The heading is fine its just the altitudes the FMC>gets wrong.>Thanks for your patience, i think mine is running out lol.FMC will NOT land the plane. If it did, we wouldn't need pilots! :)You have to understand that real world FMC's/Aircraft are nothing like the cheapened autopilot that comes with default FS. in fact, forget EVERYTHING the FS default aircraft have ever taught you.Points you brought up:-Your aircraft didn't descend because>>>>you didn't reset the MCP to your descent altitude This is exactly the opposite of the climb.-Autoland is not neccessarily programmed in the FMC, but with the NAV/RAD page on the FMC. You tune the nav radio ILS frequency and turn on all three autopilots (triple redundancy).-"Drag Required" is the FMC telling you to deploy the spoilers to decrease the acceleration of the aircraft in the descent.May I suggest you start with a tutorial flight to "learn the ropes", followed by READING the manual on how the autoflight system works. Again, autoflight is not a "set and forget" system. You, as a pilot, have to constantly monitor what the aircraft is doing.

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Ah, so the FS default AP is nothing like the real world? It seemed too good (easy) to be true and now i know it is.What do you mean by descent alt? dont quite understand what that means, talking about altitudes when i enter an approach into the FMC a bar comes up on the Flight Display. It looks like a glideslope to me and has numbers on it. On the Nav/rad bit if i enter the freq of the destination airport will it fly like the Direct GPS system on the default FS? or do the beacons/airports have a certain range? I'll try to read through the FMC guide but it is quite long for a manual, last time i tried the tutorial flight i got an error, but i'll try it again tommorow and see how i do.Thanks again, ive been used to the default aircraft and im finding it hard to adust to this complex machine, thats why i sound so dumb.lol.

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>What do you mean by descent alt? dont quite understand what>that means.....That means you set the lowest cleared altitude in the MCP.Example:ATC: "Flight XYZ, descend and maintain FL180"You: "Descend and Maintain FL180." Action=Dial in 18000 in the MCP. When the aircraft gets to the ToD point, VNAV will start the descent but will level off at 18000. Each "step" down as cleared by ATC you enter that cleared altitude in the MCP. This is called "Altitude Protection". The idea here is to never let the aircraft descend below a cleared altitude.>talking about altitudes when i enter an approach>into the FMC a bar comes up on the Flight Display. It looks>like a glideslope to me and has numbers on it. As you approach the ToD, a glide slope looking thing appears on the lower-right of the ND, with a magenta diamond. VNAV will attempt to keep that diamond between the upper-most and lower-most limits of the indicator. This is your descent path. The "steepness" of the path is determind by the descent speed as entered in the FMC VNAV Descent page. The numbers you see are the number of feet either above or below the calculated path your aircraft is.>On the Nav/rad>bit if i enter the freq of the destination airport will it fly>like the Direct GPS system on the default FS? or do the>beacons/airports have a certain range? The NAV/RAD page is purely a means to control the Nav radios (as opposed to a radio stack in the 737).>I'll try to read>through the FMC guide but it is quite long for a manual, last>time i tried the tutorial flight i got an error, but i'll try>it again tommorow and see how i do.>Thanks again, ive been used to the default aircraft and im>finding it hard to adust to this complex machine, thats why i>sound so dumb.lol.You HAVE to read....and sometimes re-read.....the manual in order to grasp what this thing does. You don't have to read through all the systems first. Stick to Autoflight and the FMC, then work into systems. It is a complex machine, but is not hard to understand once you get it. The biggest problem that most folks have, and you are a perfect example, is what you *think* it should do based on experience with default FS9 aircraft. As I mentioned, forget E-V-E-R-Y-T-H-I-N-G you know based on the default aircraft because it creates a mental block on what real aircraft are capable (and not capable) of doing.Happy Reading!

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I landed for once!. Im sure i did it wrong but i landed. Tha Vnav kept turning off saying check MCP ALT and then it said unable path or something about a path, so i went down the the alt shown in the legs pages, then that glidsplope thing came up bottom right of ND, at first i went miles too low then had to cilmb, then was doing down at 1700 -VS then put it too about -1000 when it told me to pull up etc, landed far too late and only just kept it on the runway even with Autobrake set to max. Just got to try again but make sure i land it sooner as i had to turn around on the runway to reach the taxiway, which in reallife would gain a fine or something im assuming. Have i done it right? Just seems the VNAV turning off means ive done it wrong, with those errors it gave.Still im glad i actually landed, think im getting there.

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"[The}Vnav kept turning off saying check MCP ALT..."Again, that is the FMC telling you to set your MCP ALT to a lower altitude. If you are cruising at 35,000 ft and your aircraft crosses the T/C, but you still have 35,000 ft in the MCP...IT WILL NOT DESCEND! You have to tell the aircraft it is safe to descend by resetting the MCP to the next cleared altitude."......and then it said unable path or something about a path"Because you stayed aloft too long. The descent path became too steep for the aircraft to track.VNAV is NOT a precision approach tool! You cannot program altitude restrictions in the FMC and expect the aircraft to "autoland" via LNAV/VNAV. It doesn't work that way. LNAV/VNAV will get you to the Final Approach Fix (FAF) just fine, but YOU have to tell the aircraft to slow down and dirty up once inside the FAF. You're best to turn off the LNAV/VNAV once the LOC is intercepted and let the A/P fly down the ILS.Again, read the manual. I feel that you are misunderstanding what the FMC and the Autoflight systems are capable and not capable of.

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Here a basic on the MCP altitude vs FMC cruise explaniation: "The AFS (Auto Flight System) uses the MCP vs FMC altitude to protect the airplane from . . . well, the pilot. (At least this will be one entertaining way to look at it!)During climb, the AFS will not climb above the MCP's altitude. AFS realizes there will probably be altitude constraints during a climb scenario and just wants to make sure the pilot stays involved. It does this by making the pilot dial in intermediate altitudes into the MCP. AFS then refuses to climb above that MCP altitude until the pilot reaches up and dials in a higher altitude. Again, it then will only climb to there. Then, each the pilot selects a new altitude (with Vnav engaged), the climb happens in the pitch mode VNAV SPD. This intermediate altitude is then captured in the pitch mode, VNAV ALT.The FMC has calculated altitudes that the airplane can economically (

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Sam,info like what you posted is not in the manual. The manual is more of reference or encyclopedia like.The heurestics or best practices are something else only a practicing pilot (practising sim pilot as well) can teach.Thank you.MannyPS: A storyboard explanation (in an ATC environement) for an entire flight is sorely needed. Something that follows a basic tutorial. This one need not have graphics like a basic tutorial may require. This one should be more conceptual like that post.

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>PS: A storyboard explanation (in an ATC environement) for an entire flight is sorely needed. Something that follows a basic tutorial. This one need not have graphics like a basic tutorial may require. This one should be more conceptual like that postI'm working on one at the moment but it is a big project. Plus I'm waiting for the 744F to come out so I can include any new features. It will be a full flight report of a return sector, about 2-3 hours each way.I'm about to canvas the forum members for desired features so watch this space!

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Sam,Spot on with the description. I'm glad you put it all on paper (ok e-paper). I didn't want to go into too many details, as you well know, it could take a month of Sundays to write all the permutations of VNAV.If you ever get a chance to read Mike Ray's book on the 747-400, you will find a quote in there that "67% of commercial airline pilots dislike the use of the VNAV feature", presumably because line pilots feel they "loose control" of the aircraft in VNAV and opt for FLCH instead.

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Think im getting the hang of it, just wondering what you guys do when making an ILS Approach, I know you guys have been saying forget the default FS, but what i did was fly a route to about 30 NM's away from the airport, then fly it myself to the correct position such as downwind, left etc, then engage the APP button on the MCP. I might do this with the PMDG, because sometimes the route ends without actually ending if that makes sense? What i mean is a fix is entered but the AP only goes about 5nm towards it instead of actually going over the fix/approach and then the plane is very close to the runway forcing me to perform a go-around. Is this normal pratice to manually fly the aircraft to make an easier approach for the ILS? The only probs i have now is the stalling of the aircraft, i'll just have to change the landing speed in the FMC and maybe land with more flaps.About the project i would just like to see simplier instructions, althought pictures are included in your manuals they are still very complicated, i know the PMDG isnt for your average simmer but its still very hard to understand, it gets boring reading it all and i tend to skip pages and then complain whey i cant do something when its in the manual, then i blame the plane when its actually my fault.I would like to see a step by step guide without the cold and dark if possible, like a basic quick as you can guide which we can use to fly the plane with the minimum of effort, like the FMC easy programming guide by Brett Donahue, big pictures little text but is explained very well.Lastly the FMC cant calculate an auto-route between airports can it?Thanks again!

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>Think im getting the hang of it, just wondering what you guys>do when making an ILS Approach, I know you guys have been>saying forget the default FS, but what i did was fly a route>to about 30 NM's away from the airport, then fly it myself to>the correct position such as downwind, left etc, then engage>the APP button on the MCP. I might do this with the PMDG,>because sometimes the route ends without actually ending if>that makes sense? What i mean is a fix is entered but the AP>only goes about 5nm towards it instead of actually going over>the fix/approach and then the plane is very close to the>runway forcing me to perform a go-around. Is this normal>pratice to manually fly the aircraft to make an easier>approach for the ILS? "Normally", that is to say entering airspace in a congested area like LAX, the approach controllers will vector you from the end if an assigned STAR, even though you "should" have fixes all the way through the Missed Approach. Example: SADDE6 arrival ends on the 070 from SMO VORTAC. After leaving the SMO VORTAC on a heading of 070, ATC will then vector you to intercept the ILS (usually 24R for this particular approach). You would then do exactly as you described; arm the APP when vectored on an ILS intercept and let the A/P fly you down the slope. You "should" tell the FMC what runway you are landing on, that way the FMC can arm the ILS frequency ahead of time. You then should check the LEGS page for any DISCOs and close the gaps, creating one continuous flight path.>The only probs i have now is the stalling of the aircraft,>i'll just have to change the landing speed in the FMC and>maybe land with more flaps.YOU still have to set the final approach speed into the MCP (the FMC will tell you the approach speed based on weight. "Usually" Flaps 25 unless you're REALLY heavy, then Flaps 30.) This is all located on the "Approach" page on the FMC. Read the manual to figure out how to get to it. (HINT: Index>Approach )>Lastly the FMC cant calculate an auto-route between airports can it?No, nor does it interface with the FS9 default flight planner. The FMC is a stand-alone unit. There are, however, utilities that will allow you to convert an FS9 plan into a PMDG FMS plan. You can then load it via the "CO Route" entry in the FMC.

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Manny, thanks for the feedback . . . and especially glad it made some bit of sense. (Sometimes I wonder!)

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Ted, Yea, I sure do agree. Vnav is probably the toughest part of FMC navigation. I think I saw a similar study about human factors. They surveyed a batch of 747-400 active pilots and asked them some more advanced Vnav questions. They just didn't know. I think this lack of detailed knowledge is the big factor in the current dis-comfort level with Vnav. You know, Vnav was part of the original FMC suites in the B757/67 airplanes, but it took years to get the Vnav portion of FMC directed navigation actually certified. It wasn't a systems problem. The crews just didn't get it. That's exactly what we're seeing here too. Vnav is not as intitutive as Lnav. You probably notice that a lot of the questions here are about Vnav. Little bit about Lnav, but the big learning 'speed bump' is Vnav. There's hope though. PMDG/LVLD may not recognize it, but they are raising the 'next gen' of commercial pilots. FMC operation is going to be second nature to this next group that is coming up. This will be because they had a computer game . . . that was SO spot on . . . that they are learning right now, with these sims, how these systems work. This is a very good thing.But, let

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Sorry Read my next post, cant seem to delete this one, replied with quote and it placed it 2nd to last instead of newest post.

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Ted,>Yea, I sure do agree. Vnav is probably the toughest part of>FMC navigation. I think I saw a similar study about human>factors. They surveyed a batch of 747-400 active pilots and>asked them some more advanced Vnav questions. They just didn't>know. I think this lack of detailed knowledge is the big>factor in the current dis-comfort level with Vnav.>>You know, Vnav was part of the original FMC suites in the>B757/67 airplanes, but it took years to get the Vnav portion>of FMC directed navigation actually certified. It wasn't a>systems problem. The crews just didn't get it. That's exactly>what we're seeing here too. Vnav is not as intitutive as Lnav.>You probably notice that a lot of the questions here are about>Vnav. Little bit about Lnav, but the big learning 'speed bump'>is Vnav. There's hope though.>>PMDG/LVLD may not recognize it, but they are raising the 'next>gen' of commercial pilots. FMC operation is going to be second>nature to this next group that is coming up. This will be>because they had a computer game . . . that was SO spot on . .>. that they are learning right now, with these sims, how these>systems work.>>This is a very good thing.>>But, let

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>Lol. Talking about crashing i crashed on the runway today. On>final everything looking great, slowed down the 160 to make>sure, speedbrake, flaps 20 but when i hit the ground the plane>bounced so i pushed the nose down, and apparntly thats a>crash.Though I have seen some RW 757 pilots do it, you shouldn't have the speedbrake out and the flaps out at the same time, it's considered "bad form". The flaps will provide enough drag to start squirting off the excess speed. Once you start throwing out the flaps, get your hand off the speedbrake handle! Flying tip: you should be at approximately 180 kts while intercepting the Localizer. Start slowing her down to so as to be at the final speed/flaps setting as she pushes the nose over for G/S intercept.

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So i want to be continually slowing down? is that what you mean by final speed/flaps? Another question, might be because of speed, on all my approaches the plane seems to sway from right to left and cant keep her wings level. This happens more when at higher than usual approach altitudes or when at high speeds. Whats the best landing speed/flap position do you think? I would of thought 160/20 would be slow enough but as i found out its not, am i bouncing because im landing too hard? Do you think i should disengage the AP when at 200 feet and push the nose down? or will that also result in a crash?

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Don't worry about the math. I have a pal that is a pilot instructor for Boeing/Flight Safety. He teaches "performance" for MD11s. That's where the math would come in. Calculating Vspeeds, max weights, etc. I've been through his classes and at one point said "Dang, I need my calculator." He was on me like a dog saying "If you need ANY math skills in my class, I'm doin' something wrong. Now, what IS the problem?!" My problem was that I was not reading the chart correctly. Actually, I was all done reading the chart and was trying to figure our how the engineers created the chart . . . but this is absolutely NOT what a pilot should be doing (Thankfully, I'm not a pilot!). It's the engineers that need advanced math capability. Actually you'd be surprised at the math level he described of his 'average', 20 year experienced pilot student (in for recurrent training). He trains these guys day in and day out. If you even know the difference between a numerator and a denominator, you are ahead some fully experienced line pilots. Other than basis arithmetic, there are NO math skills required. You need to be able to work charts . . . or the more modern equivalent, a laptop PC.So, that's not a problem. Military training is free. So, if you want to be a pilot, it's yours for the taking.Now, you actually crashed ON the runway. That's MUCH better!

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