Question for Real World 744 drivers...

[kmanning 12]

Hi James,I have not seen any difference in the way it taxis either. I removed the original sim1.dll and moved it to the desktop as a back up. I used the file that was in the link ftp://82.176.145.29/ that was posted by B9100Mech. But I'm not sure if this is the correct module or not. Nobody has not answered my question about where to get this new module and I still want to know. The thing I notice is even after I put the module I had downloaded from ftp:82.176.145.29, the version number and file size were exactly the same. So I don't know if this is the newer module or not. I still want to know where to get this new module. Eeryone talks about this module but nobody has said, specifically, where to get this new module. Is the module at ftp://82.176.145.29 the new module? If so, why is the version number the same as the one I had? I have the same problem as you. I give it a little bit of thrust and it wants to shoot off like a rocket, and I only barely move my throttles on my joystick, and it is calibrated. If I back off, it wants to come to a complete stop. It is very aggravating to me. What I have to do is use my keyboard to fine tune the thrust. I use about 35% N1 but I do have to very this a little as I'm taxing along and when I'm turning corners. Of course, it does depend on the gross weight of the aircraft. As I understand it, the real 747 drivers say that there's enough residule thrust to make it roll, even at idle. I've noticed in the 747-400, Allan adds a little thrust to get the plane started to roll and then he moves the throttles back. But it's hard to tell just how far back and it looks like he moves them all the way back. I hear different stories about this but I do know that wherever the problem lies, the PMDG 747-400 DOES NOT taxi and roll like the real thing. I didn't say that the PMDG 747-400 was at fault. It may be the fault of the simulator, as I've been reading. I'm saying that it does not taxi like the real thing, and it doesn'tKen.

[michal 44]

>I have not seen any difference in the way it taxis either.You should actually first see a difference with other aircraft, say even the default Skyhawk. I see a difference immediately, I can now taxi with less than 1000 rpm. If you see no difference either you got the wrong file or .. you just don't see it. ;)Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

[744pilot 0]

Question: I didn't change my SIM1.DLL but how come that the B733 from FeelThere taxies without any thrust necesary (it just keeps accelarating) and the Queen needs allot of thrust?

[Guest jcomm]

I believe this has to do with tradeoffs...The PMDG team had to edit the /thrust/mach tables (506 and 507, if my memory doesn't fail...) in order to get acceptable fuel consumptions at various flight levels. This has it's drawbacks because MSFS's turine model is far from pefect/complete.They had to cut on thrust at low N1s/Mach numbers, and indeed not even using that modified SIM1.DLL file can be of help in this area.Anyway, this is probably better than spoiling fuel consumption after you get airborne and climb to your cruise levels. That part represents the most significative one in terms of fuel consumption...

[Guest BodoM]

I am sorry, that's not the case. The taxi speed at idle thrust has nothing to do with table 506/507 and fuel flow.The thing with "making the aircraft taxi by itself" at idle has something to do with the strenght of N2 output at given N1 (idle thrust). This can be adjusted in table 1502. The problem is that if you set the N2 output that high to make the aircraft taxi 'realistic' you will have problems to decellerate the aircraft in descends as you need additional drag to hold the selected speeds.This has been discussed long time ago in the PIC767 forum and it was teh main reason why the team did not design the FDE that way to meet the taxi behaviour. ___________________________Best RegardsCpt. Bodo M

[Guest jcomm]

Exactly!But isn't it 1506 as well ?

[Guest capntom]

I have flown the 747-200 and 400 for about 10 years (now 7 years as 400 capt). I think she taxi's OK. The real plane takes a bit of fiddle fussing and anticipation, don't get bogged down, don't get too fast etc. That's an ocean liner you are driving, not a sportscar!Tom

[Guest jcomm]

and this one doesn't move at all at iddle, over the all range of possible GWs, unless you keep giving throttle....The real thing happily accelerates on more or less flatten¬ slopped surfaces, and that's why you turn off 3 & 4 while taxing in most times...

[Guest D17S]

Tried taxing on 2 once. Not a happy experience. Bogged down on a corner and figured TO thrust might be a bit too much for the little checkered building I figured was back there somewhere. Tower's hollering. Mic in one hand, starter in the other. . . that's 20% . . . umm, would someone please get the fuel lever? Those old -200 can't start 2 at a time . . . but yes BTW, they will start without boost pumps. Ahh the good old days, NOT!

[Guest capntom]

If you shut down 3 & 4, I don't think you could taxi at all. additionally normal brakes come from # 4 hydraulic system.Engines are numbered 1 thru 4, left to right. the Inboards are 2 & 3.As to the sim, I think that the PMDG plane is well modeled, I did modify the runway friction values to a more realistic value quite some time ago, which has helped ground handeling of a large vareity of planes. I believe this was illuded to earlier by another.

[xkoote 57]

To capntom and BodoM,I personally have flown the MD-82 for 6 years. The 747 is quite a bit heftier. But even so I do feel that idle thrust can be a tad more. You all know I'm being - to coin a dutch phrase - a "miereneuker" (ant f**ker, or someone who tries his best to fiddle around every little flaw or subject). This is only personal prefernce of course. But time after time at TOD I'm left feeling that my Mad Dog didn't descend at this speed to maintain e.g. 320 kts. Of course it all depends on weights and such.For example on the MD if you were descending at MLW and at TOD don't think 3000 fpm will keep your speed in check. She'll run away. Also at 10,000 don't think 1700 fpm will keep you at 250. She'll also nip you in the but. But maybe that's because that darned thing looks like an arrow. To capntom:Don't you feel as well that the PMDG 744 can stand to be a bit harder to slow down compared to real life?To BodoM:My thought was that I can - together with the updated SIM1.dll - adjust the value you mentioned in "table 1502/6". This will give me a more "slippery" 747, while also aiding in reaching that idle taxi capability. If so, what in the heck is table 1502/6 and what program can I use to modify that value?Xander

[Guest BodoM]

Xander,I personally would not modify anything in the 744 airfile after I altered the SIM1.dll with a hex editor. Since that I do not need that much thrust anymore to make it rolling and that's OK. Keep in mind that only a very light to medium loaded 747 would taxi by itself in idle thrust, but defenately not a very heavy one.The discussion about "taxi by itself" was more focused on the 737 and 767 as they definately taxi by themself. As I said, the PIC team denied to do hat as it would have caused trouble at descends to decellerate the aircraft in a realistic way without using spoilers all the time.The PMDG 737NG had a good balance between required taxi thrust on ground and 'idle drag' in the air. However, sometimes you also needed to apply spoilers to mantain teh speed at VNAV descend. >>If so, what in the heck is table 1502/6 and what program can I use to modify that value?Table 1502 defines the N1 numners vs N2. So there you can adjust N1 number readout on the gauge according to set N2 thrust.TBL 1506 defines thurst vs CN1* which can be adjusted to get appropriate thrust at a given CN1 * CN1/CN2 are 'Corrected N1/N2' The panel gauges indicate N1/N2. N1=CN1*Sqrt(TAT/288).You can modify these tables with a tool called "airEd". It is freeware and can be found at various FS sites.___________________________Best RegardsCpt. Bodo M

[xkoote 57]

Thanks Bodo,It's pretty plain to see that I should stick to flying these things and not modifying them, hehehe !I'll download AirEd and see what I can find out. Used to do some basic cfg editing way back in FS98. But I think I used that same application. I may try adjusting my parasite drag. I know that fuel consumption will be affected. An NO, I won't ask support stupid questions that are of my own doing. It's working perfectly now, so any deviation on that would probably be my fault.Bodo do you by any chance the table for parasite drag out of your head?Xander