Hi,I'm developing some "glass-cockpit" instruments for my ATR72 cockpit and working around the PFD (primary flight display) I'm "facing" the implementation of the Flight Director Bars.The thing that I don't know is how the flight director works.Considering the vertical bar of the FD, the movement to the left or to the right is proportional to the difference of the current aircraft heading and the heading I set on the autopilot (HDG)?I mean something like: FDmov= HDGaircraft - HDGautopilot?I didn't find so much documentation about it.I hope I was clear explaining the thing.Regards,Bob

There are variables in FS for the FD. You just get them out of fsuipc. I did it and it worked great.Just in case you don't know what they're for (i guess you do, but none the less...) when flying manualy you can still set the autopilot heading and altitude, approach etc with the autopilot turned off. The flight director will indicate you just like on an ILS where to turn/climb to.

Thanks for the answer.Well...I already found those offsets but monitoring the value (with FS Interrogate) that they contain, most of the times it didn't reflect the current position of the FD bars.I mean...I tried to fly with the ATR72 (panel by Sanchez-Castaner) and when the vertical or horizontal bar moved, the value into those offsets didn't change or changed later when the bars already moved.I thought that those offsets contained the current position of the FD bars but "analyzing" their value with what I saw on the screen, it seemed that they contained a "target" value not the "current" value...I hope I was clear.They maybe contain the value that the pitch or the roll must have to "drive" the aircraft according with the altitude, heading etc. settings of the autopilot (active or not) but not the current position of FD bars.To explain better...let's suppose that the value related to the vertical bar was "24", the bar moved on the left (or on the right, don't remember) and then the aircraft started to turn on the left.The value was still "24" when the vertical bar started to move toward the center but the value was still unchanged, the bar crossed the center stopping on the right but the value was still "24", then after some time it started to decrease from "24" to "0" while the vertical bar started to move toward the center again.This got me a bit confused.Then I thought that those offsets didnt' reflect the current position of the bars but something else...but I don't know what.Regards,Bob

With FSUIPC, read the request into a double type variable.The bank variable is at offest 0x023F0 and the length is 8. The pitch variable is at offset 0x02EE8 and is also length 8. Using these variables, I can extract the data. the 24 relates to positive (right/up) bank/pitch of the bars (0 is no pitch/bank - 127 is positive pitch/bank - -127 is full negative pitch/bank).Have you tried using FSInterrogate with constant updating of the read buffer to see the value change?Good luck.

Yes...I've already used those two offsets and monitored them...anyway...I think I found the solution.I didn't have any confirm but probably those offsets contain the max pitch and bank that the aircraft must assume to reach the set HDG or altitude.Considering the bank value, it grows to reach about "27" (with an ATR72) or "-27" when the difference between the current aircraft's heading and the HDG setting is relevant.I mean...if the aircraft's heading is "0" and the HDG setting is "90" the offset at 0x2EF0 contains about "25", if the HDG setting was "5" the offset would contain a smaller value...it decreases to 0 when the aircraft's heading gets close to the HDG setting.So the position of the vertical bar of the FD is proportional on "how far" the aircraft's heading is from the HDG setting.I implemented it on my glass cockpit and it works.Thanks, regards.Bob

The FD indicates the pitch and bank required to attain a selected vertical speed, altitude or heading. If you need to turn right to a heading and it requires a full 30 degree bank, the bars will be full over (-127/127). Once you bank to 30 degrees or whatever the necessary bank FS figures, the bars will be centered. Assuming a 30-degree bank, at 15 degrees bank, the bars will be half-deflection (63 or 64 in the value field).I dont know why you're only getting small numbers. It may be due to you using wrong conversion techniques. Post your code and I'll see if I can figure out what's wrong.Hope this helps.

I will try to modify the code according to what you wrote...probably I wrong interpreted the "behaviour" of the FD.Regarding the values of those two offsets, I use FS Interrogate to check offset values and the value I've read never got over 27 or -27.May be due to the panel of the aircraft?Consider that I tried with the Flight One Atr72 and with Eurowings ATR72 with the panel of Sanchez-Castaner reading the same values.I will let you know if it works.Regards,Bob

Just for grins, load up the default 737 and see what values you get...just to eliminate the possiblity that something is scaled wrong....

Aaron,now it works !!I modified the code according to your explanation and now it works as it's supposed to.I checked (both with FS Interrogate and FSLook) the values of those two offsets with the default Boeing 737 and the bank values never got over 27 or -27.I tried with several aircraft and I've read more or less the same max value.Thank you, regards.Bob

amen, that is wonderful news. I cant wait to hear about your progress into other areas for your software. Mine is coming to fruition here as well for my NG software, so I can feel the enthusiasm that something works right for once.Congratulations and good luck on the rest.