PMDG 747X Altitude Holding Problem PLEASE HELP ME!

[Guest Isaak]

Hi all,I recently got my 747-400x from PMDG after waiting quite a while for. And after I got it, I took it out for several test flights which is where I discovered, to my disappointment, there was a problem with the plane that I paid 93 flippin dollars for. Every time I select an altitude for the aircraft to hold on on the autopilot, it will reach the altitude but it will never stay level, the autopilot will make the plane constantly go back and forth within about a +/- 500ft range. Please can anyone help me? I'm not using any FSUIPC or Active Sky or anything. But I just got this plane and I was really excited about it and I had to find out on the first day that there was already a problem with it;( so if anyone could help me, that would really make my day.....

[FLEX1978 373]

Sign your real name it's the rules... Now whats your ZFW? how much fuel on board? What's the Max Alt on your FMC? If you can post a screenshot.Rob

[Guest Isaak]

Well to tell the truth i never really set up a maximum altitude in the FMC. I just put in about 2/3 passengers and 60% fuel. And I mean, if everybody is getting the same download of the plane as me, how come they don't have this problem? I just thought paying that much money for it would make sure that I wouldn't have these kinds of problems.....sighIsaak

[FLEX1978 373]

< how come they don't have this problem? > You payed for a high quality 'realistic' product it's up to you to study to get the best out of it.Rob

[Guest Isaak]

So you're saying it's not a bug in the program, it's an error I'm making right? Isaak

[Farlis 2,281]

2/3 of Passengers and 60% Fuel you say? Gives me a gross weight at around 760.000 lbs? That about right?So at what altitude do you try to cruise? Not that I want you to bother in with actual procedures and calculation tables... But with that load you should cruise at around FL320.Anything higher and the aircraft will have trouble holding the speed.But from your comments so far, you actually don't seem to bother about operating this aircraft in the proper way. And you complain that it doesn't work as you expect it to?Pshaa...Karsten

[Guest Isaak]

I really want to use the aircraft in the proper way and I'm very capable of it, and it was my original intention to do so when I got it, so I could learn how to use the FMC and in combination with the aircraft's IRS systems, etc. But that won't be possible if the plane can't even hold an altitude properly. it gets even worse at holding the altitude during turns as well. All I was doing was step climbing with the altitude hold and V/s hold. I tried 10000ft and that was terrible so I just kept climbing and to FL320 as you said, and yes that was around the weight of 760.000lbs. I really want this whole thing to be my fault instead of the aircrafts....but does it really matter if I'm just trying to hold an altitude or do i have to really learn and go through all the procedures to keep the aircraft at level flight even when it's following a route or turning?Isaak

[Farlis 2,281]

All you need is vnav. Why would you try to change the altitude at a predetermined vertical speed if the FMC can do all the calculations you need?And you still haven't given specific data. At what vertical speed did you climb? What airspeed did you try to maintain? At which altitude did you encounter problems?Screenshots would really help.Karsten.

[Vic1 3]

i have been flying the pmdg 747 since it first came out and am pretty experienced with it, i can say that i have seen a situation where the aircraft reaches its mcp set altitude in vnav but overshoots slightly then tries to correct but is heavy handed and over compensates and drops below the assigned alt this tends to continue and repest or worsen with speed deterioration slightly unless there is pilot intervention in the form of AP diconnect and manualy achieve level flight then re connect the auto pilot and allis well. This is something that only happens from time to time sometimes wind shiftss are a factor but other times i can find no explainationis this what you are seeing??kav

[cavaricooper 2,614]

Isaak:FWIW I have seen many "pilots" operating the 744 online at grossly unrealistic altitudes. She's a fat girl and flies lower than some other a/c types. Play with the FMC, entering different FLs and you will see (if your PERF INIT is correctly completed) that there are different solutions for the flight profile. Look for appropriate steps (I use 2000), change the FLs up and down and see what that does to your LEGS page- its all quite realistic.While you're at it, please get TOPCAT (http://topcat.ofplan.net/?page=news) so you can operate the T/O segment realistically.Once you have some familiarity with the optimum operating altitudes, spend a bit of time with the provided manual- its quite good- really.Then buy Mike Ray's 747 book, Bill Bulfer's Big Boeing FMC Guide, the Virgin 19 ITTV video, the Oasis Video and the Air Atlanta Icelandic Video- you can probably skip the CorsairFLY one. In regards to your query...."but does it really matter if I'm just trying to hold an altitude or do i have to really learn and go through all the procedures to keep the aircraft at level flight even when it's following a route or turning"- the short answer is, "Yes!"Once you have digested all of this, I'm guessing she will hold altitude better. Despite the $97 cost, I promise she is among the best value for your simulation Dollar- period.Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 - FSGS System Unification | 2 x APC UPS | Coolermaster Stacker 830 SE | Gigabyte P35 DS3R | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Sony 40" Bravia XBR | Creative X-Fi Fatal1ty | Bose Companion 5 | 2 x 1 GB Corsair XMS2 | 2 x 320GB WD Caviar RAID 0 | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |

[Guest Mower]

What I would really and sincerely like to know is if he has read the manual in its entirety yet. Only THEN should we be trying to resolve this IMHO. Carry on.

[madmansd 0]

I have a problem my fmc says i can climb to 33000 ft at.855 mach but as soon as soon as i get to 260 it levels off and refuses to climb any further is is a new feature over the fs9 versionalso the airspeed drops is this a problem Regardsantony barker