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Guest FlyinJ

Mach speed hold

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Is anyone else experiencing a problem with the autothrottles holding the commanded Mach speed in the Learjet during climb and descent? I usually climb at 290 kias (abv 10000 MSL) by setting the speed bug to 290 and engaging the SPD hold button on the MCP. While climbing, I adjust my VS so as to maintain 290 kias. That all seems to work as the autothrottles manage to hold the commanded speed of 290 (+/- a few kts) just fine. Here's where it gets weird. As I pass thru FL300 on my way to FL350, the mach number displayed at the bottom of the speed tape reads .740. It's at this point I switch to Mach hold by pressing the SPD dial on the MCP. At this point I would expect the commanded (magenta) speed displayed at the top of the speed tape to switch from 290 knots to .740, but instead it switches to a Mach number much lower than .740 and the speed bug lands at the bottom of the speed tape. And even after I use the speed dial to dial in my desired Mach of 0.74, the speed during the remainder of the climb doesn't hold at M .740. It continues to slowly accelerate well beyond the commanded mach of .740 all the way up to mach .810 by the time I level out at FL350. I didn't have this problem in FS9. Any suggestions would be appreciated. -Jeff

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Hi Jeff, Alexander Barthel has a file in the library which addresses some issues with the Lear 45, along with adding some very nice enhancements. According to the readme one of the fixes is: "If mach hold is used, the speed bug does not move away when the mach/IAS ratio changes during climbing."Hope this solves what your experiencing. Here's a link to the file: http://library.avsim.net/esearch.php?CatID...gau&DLID=102349 along with my thanks to the author for providing it! Regards, Kendall#1: E6750@3.2GHZ/Coolermaster HyperTX2 Gigabyte P35-DS3L 4GB Crucial Ballistix Tracers PC6400 Seagate 250GB 7200.10 SATA2 Gigabyte X800XT -Cat 6.12's CH Yoke/Pedals/Saitek Throttle Dual Monitor: Dell 2405/1905 #2: Dell 8400 3.2 H.T. 3GB PC4200 Diamond Xtreme/Logitech X-530's

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Kendall,You da man! That fix you led me to was just the ticket to solve my problem (as well as adding a few nice extras to the panel). Thanks!Jeff

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