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Joe L

Cruise Speeds - 0.81 mach overspeed?

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Cruising on LNAV / VNAV at 34000, 200k lbs gross weight. STD temps (-52 deg SAT). The Delta PW overwing exits 757-200.Cruise is set at 0.80 in the CDU/FMC. On a planned RTE.Barber pole and red line on the speed tape occurs at about 0.81 mach. Your manual lists mmo at 0.84 mach (other non sim 757 sites list 0.86 BTW)This makes a std 0.80 cruise look as if right at the red line.Furthermore, I go to SPD | ALT HOLD | LNAV |CMD and enter 0.82 mach just to see what happens, overspeed warnings etc. AC will not exceed 0.806 mach no matter what (going on 15 minutes with no accel).EICAS shows CRZ, Reference/Target EPR green carrot and MAXIMUM EPR amberline show 1.52, but engines / EPR Pointer will not go above 1.41.If I go back into VNAV and select enter and exec 0.82 as my speed it reflects in the ADI Speed tape (although well over the red line), but magneta TARGET EPR stays at 1.41, and again, no acceleration at all. Selecting a lower speed will result in deceleration.Shouldn't 0.82 mach in these conditions be attainable?Joe Lorenc

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noted and added to the list to be looked at.Has anyone else experienced this?

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Steven please Skype me and look for BUG 463 in the bug traker.Cyrille de LattreAsus P4P800/PIV 3 Ghz/2 Giga DDRAMATI X800 GT 256 MegWin XP SP2 / FS9.1 PSS Beta tester

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Although, Joe, could you confirm this is with the new interim fix, or the release set? Cyrille de LattreAsus P4P800/PIV 3 Ghz/2 Giga DDRAMATI X800 GT 256 MegWin XP SP2 / FS9.1 PSS Beta tester

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QUOTE:Although, Joe, could you confirm this is with the new interim fix, or the release set?This was with the interim fix downloaded about 10 or so hours ago.Thx for the rapid looks.Joe Lorenc

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Yep, i saw this last night on my KEWR-KORD run with the updated installer. Still a very pleasant flight :)-Paul

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hello folks,yup, got the same problem. At FL350 can only still cruise at M.78. Higher than M.79 or so, is overspeed... But i

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Great picture!:-)The graphics quality is superb. I think this should please the majority of users.Unfortunately for the "systems purists", RR engine data shown in the picture is very inaccurate for that flight condition.:-(..anyway I guess this won't be a concern for most users as well.Tom

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>Great picture!:-)>>The graphics quality is superb. I think this should please the>majority of users.>Unfortunately for the "systems purists", RR engine data shown>in the picture is very inaccurate for that flight>condition.:-(..anyway I guess this won't be a concern for most>users as well.>>Tom>*screenshots are like 800-1mb in size*Hi Tom!I may be doing something wrong in that screenshot, as I just simmed it up to altitude, and here is another that I didn't just sim on up, the MFDs are set the way they are to be similar to ATA Airlines 757s. I'm just messing around with the airplanes, and not using any checklists, manuals etc, just the common knowledge one has from using the PSS/PMDG/Dreamfleet Big Boeings.http://img371.imageshack.us/img371/5989/b752panelcw4.jpgPaul

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>Great picture!:-)>>The graphics quality is superb. I think this should please the>majority of users.>Unfortunately for the "systems purists", RR engine data shown>in the picture is very inaccurate for that flight>condition.:-(..anyway I guess this won't be a concern for most>users as well.>>Tom>I'm curious to know how the data is inaccurate for that flight condition. Not being a trained engineer or trained pilot I can't tell from a glance whether engine parameters are correct or not, but if they aren't that could well be a bug that needs reporting.

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Paul,Still most engine numbers are not correct...I can give you the right figures if you want. As an example, N3 value is right out of bounds...and N2/N3 digital values do not show decimal places in the real bird.Tom

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Well, after being modelling the RB211 535E4 for 8 months, I think I know a bit about what are the proper numbers for different flight conditions..:-) As for being a bug, I wouldn't call it so, just something that visually is not as real as it gets, but that probably wouldn't affect the flight conditions.Tom

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TomI'm not an engineer either - but I have several thousand hours on RR engines on a very different aircraft [similar 2 engines but max M=1.?]. - So purely for my interest, very grateful if you could summarise what the various relationships should be in an aircraft such as the 757 in the cruise.Best WishesJohn Rooum

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