747-400 pmdg vnav altitude error?

[Guest Hawkeyeted]

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.

[Guest spiers]

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!

[Guest Hawkeyeted]

>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.

[Guest D17S]

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

[Guest D17S]

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

[Guest spiers]

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.

[Guest spiers]

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

[Guest Hawkeyeted]

>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.

[Guest spiers]

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?

[Guest D17S]

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!

[Guest spiers]

To be trained up academically is cheaper but you need serious qualifications in Science and Maths, more Science than Maths but still what i havent got. Same with the Military, im sure you need A-level Science Maths, sorry dont know the name of an equilivant American qualification.Turned the AP off on landing, the plane rose, i pushed it down NOSE first into the runway, guess what? NO crash was given, but the auto brakes disconnected and i ended going off the end of the runway, which is counted as a crash, half my passengers died of course even though as soon as all my tyres left the runway it gave a crash no matter what speed i was travelling at. Im going to try a full flaps at 140 landing see what happens.

[Guest spiers]

Still having trouble landing, plane seems to bounce and then fly at about 20 feet until i push the nose down, however this disengages the Autobrakes and then i cannot stop before the end of the runway.Thanks.

[Guest D17S]

Not bad, not bad at all.The autopilot disconnected? Unless you are doing a full, LAND 3 autoland, leave the autopilot disconnected and hand fly. Actually, if you know how to set it up, autolands are a very good initial training aid. You get to be almost a complete spectator and see what an approach should look like. Then, when you do it yourself, it will 'look right.' Just FYI, for an autoland, you have to have one autopilot and the autothrottle engaged, an ILS tuned, LOC and GS captured, then press the APP button on the MCP. You then control airspeed via the AT with the MCP airspeed selector knob. Then get flaps and gear out on schedule and slow to Vref. Arm the spoliers and the autobrakes. It will land, rollout and stop all by itself. Sounds like you are doing something with that AP, but I'm not quite sure what. The landing sounds like a too high a rate of descent(ROD). Your ROD should be about 700 fpm as you approach the runway (Notice this ROD if you do an autoland and "LAND 3" anunciate just below the PFD's FMA.) Airspeed should be at Vref for your flap setting (25 or 30 deg). At 50 feet get ready, but do nothing. At 20 feet radio altitude, reduce thrust to idle and bring the nose up smoothly to about 7-8 degrees and hold it. (Notice "FLARE" and "IDLE/HOLD" capture in the PFD's FMA if you do an autoland.) This is the flare and will slow your ROD. Let the airplane gently sink into the runway (Notice "ROLLOUT" capture as you touch down if you do an autoland). Spoilers should have been armed and will auto deploy at touchdown. This will keep you on the ground. Now reverse thrust as you gently bring the nose down. If autobrakes were not armed, apply brakes and rollout.(Not as easy as it sounds! If you don't know what some of this stuff is, be sure to ask.)

[Guest spiers]

Yeah a quite complicated post for me to understand im afraid. Landed today on the net with some others and still it bounced. Looked at the plane with the spot view and i saw smoke/some kind of "air" comming from the back tires, the plane however then went into the air again disengaging the Auto Brakes. I cross the G/s path and press the APP button three AP lights come on, L,C and R and the plane descents to the runway, however the VS is about 800 then goes to 700 close to the runway. If you can send me a video that would be great, i might record one for you but i dont have any webspace to upload it onto.Thanks.

[Guest Hawkeyeted]

>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?If you look at the "APPROACH" page in the FMC, it will tell you the correct speed for a given flap setting (i.e. options for three flap settings; 20/25/30 with corresponding speeds, base on the current weight.You can disconnect the A/P at 200 feet, but don't nose it over. Use the throttles to manage glideslope, and pitch to control speed. The closer you get to touchdown, the SMALLER the inputs need to be."Normally", you can keep the A/P coupled to the ILS all the way down to 20 ft, then turn off the A/P and A/T and let her settle into teh runway.You gotta read the manual man!