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martinlest2

Mach Hold

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It took several flights after installing (CD-ROM version) before I really got the hang of flying the 742, but now that I have, it really is one of my favourite a/c to fly. I'm amazed it's now free online (but I'm glad I bought the CD-ROM in any case - if only for the detailed printed booklet!).Still one thing bemuses (confuses?) me though - the use of the Mach button. Whenever I press it my indicated Mach goes right down and only by re-engaging the 'Speed' button do I get back to a reasonable cruising speed (c. M.82-M.84). I can't fathom this from the manual. Maybe someone could kindly tell me when the EPR/Speed/Mach options should be used. I start off in EPR at takeoff, but then find, in order to control the airspeed and keep it under 250 KIAS, that I have to change to CLB mode and then press the 'Speed' button. (If I leave the a/c in EPR mode, the speed climbs to 290 KIAS plus - I can't control it at all). Then, as I say, selecting the Mach button when I am at the usual switch-over altitude, brings my airspeed down much lower than it should be (can't get much past M.77 at 38000') - so I use the Speed button instead, setting c. 275 KIAS, which equates to about M.84. Surely this is not as it is supposed to be? How do I maintain M.82/.84 with the Mach button selected?Hope this is clear! Tips appreciated. Thanks,Martin

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For what it's worth, I notice the same things. I don't worry about it; I chalk up the mach hold reduced speed to the home office attempting to save fuel in these trying times. R-

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I suppose it's not a big deal, I fly the a/c fine using the Speed button, which is the main thing. Just slightly niggles me that with an a/c where so much thought has clearly gone into getting things authentic, that I can't use the EPR and Mach facilities as they would be used in the real-world 742.I'll try not to lose TOO much sleep over it though!!M. :-)

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Are you by chance flying with "real-time" weather? Mach, which is a percentage of the speed of sound, varies according to temperature and it may well be that changes in temp may be having an effect inside of the simulator itself. Just a though,as I can't say that I've ever run into the problem, although I tend to use the speed function as much out of habit as anything else. I do know that FS sometimes does some strange things with weather in general ( particularly wind speed and direction) so it is possible that there is some effect with temp also.Ed GreenKCLT


http://www.oncourse-software.co.uk/forum_images/fdc_beta.jpg

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No Ed, I create my own weather themes and the temps "at altitude" are constant. I think its set at -36* @ FL350 but I don't rmember if that is C or F! :-lol R-

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Use offline weather dat files in Active Sky for weather - don't usually fly with 'live' weather..M.

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Can I also point out that when switching from EPR to Speed, the autothrottle switch automatically turns off and you have to re engage it.Always make sure the green light is on.Goran

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I am STILL having problems keeping the speed down! By the time I've finished with whatever I have to do after take-off, I am up to 230KIAS plus.Could someone describe exactly what they do to de-rate the engines for EPR take-off. The only way I can control things at the moment is an inelegant scrabble to switch to CLB mode on the EPS then switch to Speed mode, but by then I am already going too fast. How do I keep the a/c at 180KIAS after take-off in EPR mode, without having to adjust throttle manually?Thanks.*** BTW - what a pity there's no RFP 747-400 for FS9. Too late by now I suppose, RFP people?!

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