# Max Cruise

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I'm looking into creating an XML gauge, which assists in the Max Cruise system already present on my Concorde panel.I plan to have this gauge as a system working behind the current autopilot. I hope to create a gauge that will function based on the following: -If AUTOPILOT MAX SPEED HOLD is on (I.e. bool, 1)And If Mach is greater than or equal to M2.00 then set VS to +50FPMElse if mach is between M1.99 and M1.95 then set VS to -50FPMAlso I would like use the temperature reading on the nose - but I can't find an a;var for it - maybe this is calculated?I have the following, but I'm not sure how to set this one out..? (A:AUTOPILOT MAX SPEED HOLD, bool) == (A:AIRSPEED MACH) 1.95 >It's the and commands that I'm not sure are correct? Also I know I have to add some missing vars, but it

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Hi Andrew,Maybe this may help.. The one problem is there is no way to "set" the VS directly and you are limited to +/- 100 fpm increments. ( Please M\$ give us both for FS2004 )(A:AUTOPILOT MAX SPEED HOLD, bool) 1 == if{ (A:AIRSPEED MACH, MACH) s1 1.95 > l1 1.9999 < & if{ -100 (>G:Var1) } + l1 1.9999 > if{ 100 (>G:Var1) } }(A:AUTOPILOT MAX SPEED HOLD, bool) 1 == l1 1.95 > & if{ (G:Var1) (A:Autopilot vertical hold var, feet per minute) < if{ (>K:AP_VS_VAR_DEC) } + (G:Var1) (A:Autopilot vertical hold var, feet per minute) > if{ (>K:AP_VS_VAR_INC) }As for the nose temp.. If you have charts or some info it could be done using speed, time at speed, alt etc..Note, the way it looks here on the forum is different since HTML has processed it. On paper the " < " would be " & l t ; " , the " > " would be " & g t ; " and the " & " would be " & a m p ; ". All without the quotes and remove spaces between characters.Regards,Roman[link:www.packers.com]GREEN BAY PACKERS] :-ukliam :-beerchug OVER Dah BEARS !!![/i

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Thanks for the help (well - code really! ;-)) again Roman. So just to be clear - I cannot use 50FPM :-( - I cannot SET the VS at all? :-eekI hope you meant I cannot set 50FPM directly?Cheers,Andrew

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>Thanks for the help (well - code really! ;-)) again Roman. >>So just to be clear - I cannot use 50FPM :-( > - I cannot SET the VS at all? :-eek NOPE -- not directly.. the code above increments or decrements until it is equal to the value needed>>I hope you meant I cannot set 50FPM directly? VS is only available in increments of 100.. You could make your own VS mode but it will not register on the FD.Regards,Roman

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Thanks Roman I decided to change a few other things. I was using a C++ type gauge and have decided to have an attempt at creating an XML layout, so I can add more graphics/night lighting to each of the gauges.I'm a bit stuck on the VOR/LOC hold switch. The one I have doesn't work with the current a;var. When I use the backcourse a;var - it engages the back course and app modes.(A:AUTOPILOT NAV1 LOCK, bool)I know I'm missing something - or going wrong somewhere :-zhelp

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On top of this - "AUTOPILOT AIRSPEED ACQUISITION" seems to do nothing! And there is no "AUTOPILOT ALTITUDE ACQUISITION". :'(I believe these are similar commands which are used in the modern airliners - known as FLCH. (Very nice version on the 767PIC). Does anyone know if such a gauge can be programmed into XML for FLCH or for ACQ? For IAS ACQ I'm guessing the aircraft would pitch up/down to attain the selected speed. ALT ACQ - well, I don't need to explain this ;-)Again thanks in advance for anyone's help (if anyone can help! :-hmmm)Andrew

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Hi Andrew, First let me correct something.. I was wrong. YES you can write a variable directly to ALT or VS.. Never seen it until late last night :-( (>K:AP_ALT_VAR_SET_ENGLISH) metric too.. (>K:AP_VS_VAR_SET_ENGLISH) metric too.. The problem is still there though that in both ALT and VS the lowest resolution you can get is +/- 100 ft or +/- 100 FPM.. didnot try the metric though but I assume it is the same.IAS Aquire --- No idea whatsover on that.The following are ideas I hope work for the 737 MCP i am working on.ALT ACQ -- No actual autopilot function. I believe it is a transitional mode that can be dispalyed on an EADI for instance..IF Altitude does not equal commanded altitude (+/- 25ft.) AND Altitude hold is on AND VS commanded = zero then you are in a transition to the altitude to be held.. I.E. ALT ACQ FL CHG -- I believe you need some kind of N1 limit here. For a climb:Crank the throttles up to the current N1 limit IF altitude = Commanded altitude then switch to ALT HLD ELSE IF airspeed is less than commanded then 0 -> VS_SET IF airspeed is greater than commanded then increase VS_SET by some value dependant on difference of Airspeed.For a decent: IF altitude does not = commanded altitude ELSE switch to ALT HLD IF Bring throttles to IDLE and Airspeed is less than commanded airspeed IF decrease VS_SET by some value dependant on difference in airspeed. IF airspeed is greater than commanded then increase VS ( zero max ) by a value dependant on airspeed difference.Something like that I hope....AS for your code above when the backcourse is on so is the NAV1 hold but configured for BC. So for your display you may want to try the following to show when LOC hold is on but not in BC mode.(A:AUTOPILOT NAV1 LOCK, bool) 1 == (A:Autopilot backcourse hold, bool) 0 == &Then for a BC display on:(A:AUTOPILOT NAV1 LOCK, bool) 1 == (A:Autopilot backcourse hold, bool) 1 == &Regards,Roman[link:www.packers.com]GREEN BAY PACKERS][/i :-ukliam :-beerchug

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Thanks again for the tips on FL CHG - I'll look into it. It's funny how MS have put in a;vars and K:events which don't operate! Along with ACQ - Max cruise/speed also do nothing! The LOC gauge I'm still having trouble with. Maybe I need to start again - I believe most panels have both a LOC/BC and APP button which all work separately. I have the BC and APP - but can't get the LOC to work without activating one of the other two gauges?Also - as the MAX Speed var is inoperative, I'm going to have to work around this. I know that the a;var BARBER POLE MACH works - so I might try to make a switch that when engaged - places this speed into the IAS window - if this can be done? Andrew

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>Also - as the MAX Speed var is inoperative, I'm going to >have to work around this. I know that the a;var BARBER POLE >MACH works - so I might try to make a switch that when >engaged - places this speed into the IAS window - if this >can be done? Thats how I did it.. C/O switch and used ratios to calculate new mach speed based on airspeed.A:Barber Pole Mach / A:Airspeed Barber Pole = A:Autopilot mach hold var / A:Autopilot airspeed hold varUsing the above ratio you can write to Airspeed hold or Mach Hold the variable referenced to the previous C/O mode.Regards,Roman[link:www.packers.com]GREEN BAY PACKERS][/i :-ukliam :-beerchug

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A:Airspeed Barber Pole? Haven't seen this one - but would be great if it works! Sorry to keep asking questions! :-shyHow do you write this to the Airspeed? Is it using a similar code to the one used in the max cruise?I really appreciate all your help on this Roman! :-)Regards,Andrew

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Andrew,I guess my question is:: How is it to work? I mean is this button going to be a MAX cruise or a Mach hold w/ adjustable MACH ? Regards,Roman[link:www.packers.com]GREEN BAY PACKERS][/i :-ukliam :-beerchug

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If IAS Hold is engaged - then when max cruise is also engaged, it will write the maximum IAS (I.e. the barber pole IAS) to the IAS hold system. This means that when both systems are engaged - the IAS setting will be constantly updated as the barber pole rises. So it will follow the KIAS up to Mach 1.95 Where I will then hope to program it to switch to follow Mach 2.00. I've seen this done on C++ type gauges - so hope the same can be done in XML. Thanks for looking into it!Andrew

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Andrew, Donot have time any more today.. But later this eve I can take some of the code already written for my MCP, modify it just a tad for what you need and send it to you.. Should be able to do it just as you described with the mach 2.0 hold to boot.1 last question.. Do you have a MACH hold in your MCP ?? And if so when above 1.95 and switching to hold 2.0 do you want it to go there and activate MACH hold? Or just stay at IAS hold , MAX cruise and adj KIAS hold to coincide w/ MACH 2 ?? Regards,Roman[link:www.packers.com]GREEN BAY PACKERS][/i :-ukliam :-beerchug

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Thanks for taking the time to do that Roman - That's very kind of you. Just to switch to Mach Hold and set M2.00 would work. In real life the aircraft must not exceed 530KIAS, M2.02 or a temp of 127* on the nose. As soon as one of these conditions are met (usually the Mach No. - but on warm flights (high ISA readings) KIAS and Temp will limit the speed. It would be nice to implement this feature (KIAS and Mach restrictions) - but I believe it might take too much time/effort to achieve. Many thanks,Andrew

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