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ALT Hold and VS

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HiJust a quick question if I may? When I dial in an ALT in the Autopilot the VS stays at 0Is there any way to edit the .cfg so it automatically populates VS say 1800fpm when selecting an ALT?Using the POSKY ERJ145 with a panels which has the Default LEAR AutopilotThanks guys!

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Welcome to the forums :)>When I dial in an ALT in the Autopilot the VS stays at 0That's correct.1: Dail in the altitude2: Push the ALT button. As soon as this mode is active, the ALT button lights up green and the VS jumps to + or - 1800fpmRegardsBernt Capt 767

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Hi BerntMany thanks for your reply. Makes perfect sense however, when ALT is 'pushed' it stays at 0fpm I have to manually adjust the VS.It seems as though this is the only aircraft I have problems with?Thank for the welcome too! :-)

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Aha, another bug.The method I mentioned works only the first time you use the sequence, ALT select, ALT button.As soon as you change the VS manually it doesn't work anymore.Only if you don't touch the VS until the autopilot levels off at the dailed in altitude and the the VS bug AUTOMATICALLY jumps to zero, this works.E.g. If you let the autopilot level off with the default climb rate at 10000ft (VS zero) and thereafter dail in 9000ft, the VS automatically jumps to -1800fpm.BTW, IRL the VS also stays at zero until you change it.First you dail in the new altitude and then you SLOWLY increase or decrease the VS, so the passengers don't even realize that a level change is in progress. RegardsBernt Capt 767

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Thank again for the insight.I am unsure why this aircraft does not automatically dial in the VS? All other fsx aircraft I have flown have been ok?I would like to know if it can be edited? I have looked in both the aircraft.cfg and the panel.cfg but without success?Thanks again and best wishes

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They have probably set this to 0 deliberately to mimic real life operations.Check in the aircraft.cfg file and see what is set for this parameter:default_vertical_speed=1800The above is the "default entry" used by all FSX's aircraft...

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Thanks guys that was exactly what I was after!Seems to have done the trick!On another note is there anyway to adjust the sensitivity of the ILS? Aircraft seems to want to 'snake' whan capturing the ILS?Thanks again everyone for your help.Cheers!

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I don't think that has so much to do (directly) with the ILS, rather the control law variables of the autopilot set in aircraft.cfg. I have a controls textbook floating around here someplace, but never enough interest in playing with the autopilot to want to really get into it.In general, though, I think it can be said that the autopilot generates a measure of error (difference between desired and actual). The proportional control increases the output in direct relation to the size of the error. A pure proportional control though can have less than excellent performance, so they add the differential and integrated control. The differential looks at how rapidly the the error is growing (or shrinking) and adjusts the output to compensate. The integral looks at how long the error has existed, and adjusts the output to compensate. Obviously, these three control laws work together to achieve the response. I suspect trial and error is not a good way to go about modifying the law, but rather some study needs to be done to better direct the changes one might want. scott s..

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HiScott S. Many thanks for the reply, seems to make sense?Anyone? - Just to clarify are the ILS parameters locked in with the .air file, or attributed to the .mdl, panel.cfg or aircraft.cfg or all of them?It appears as though many of the aircraft I fly have no issues with the 'snaking' effect of capturing the ILS. I fly Online quite a bit so if I am vectored by ATC late this seems to enhance the 'wobbly Localiser capture':-)I have one other issue: There have been several posts with users experiencing Blocky or indeed square beacon lights nay idea what causes this? Seems all the Texture files are in place? Once again the model in question is the wonderful POSKY ERJ-145 with FSXThanks again everyone!Cheers

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It's not just during ILS operations that the problem arises. If you fly the default 737 on auto in level flight and set the time compression to 16x you will notice the flightpath will look like a sine wave...

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Hi again everyone.Did anyone out there have a fix please? (All Texture files accounted for in Folder(s)!Thanks again

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Just to drop in and post some of my observations on the question.Some auto-pilots have ALT and ALT SEL. In climbing and descending situations if you push ALT the auto pilot will hold the altitude that the plane is currently at when the button is pushed. With only that feature turned on, it makes it very handy in maintaining a constant altitude during maneuvering.With ALT SEL button pushed the auto pilot will seek the altitude that is set in the altitude select window which then should require you to select the VS, vertical speed, each time the altitude select window is changed. With both buttons active, ALT, ALT SEL, I think you don't have to select the VS each time the altitude select window is changed.Snaking on the ILS localizer. Does the airplane stay within the ILS localizer fan? If so it is because of the distance from the source transmitter. Same as tracking a VOR. The farther from the VOR the more snaking that takes place when you are tracking inbound. The trapped glide slope should produced a 500 ft descent rate.

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