As someone who realizes they should have taken more math classes in skool...
Looking at the chart for KSNA it says the runway heading for 19R is 194.7. The approach chart for the ILS into 19R says a heading of 194. So right off I have a discrepancy. If I want a perfect airport, what number do I use to place 19R, because it could be anything from 194.65000000000001 to 194.74999999999999. And with the FAF being 6.5nm away how in the world do I calculate what any offset may be if I'm off by 1/1,000,000?
TBH, this sounds like a bug that's been in ADE from the beginning. And because of the bug, all the airports that have been designed prior to 1.40 need to be thrown away? Should we be posting at the AI forums to discontinue the use of ADE before v.1.40?
I need to go check Amazon and see if the have Basic Math for Dummies in stock.
Your original post ask, Who calculates to 88.123456?
Found the runway heading edit box has gone to six decimal drgrees or one one millionth precision. I just need to make it chnage from 88.1 to 88.2. Who calculates to 88.123456?
My answer was FS calculates to the 14th place.
You cannot set the runway and the approach code heading the way FS has to read it with just the tenth position. Any rounding of the runway heading by the designer or the compiler changes the difference between the 2 headings listed below.
heading="70.4899978637695" (FS stock runway)
heading="70.4631576538086" (FS Stock Approach code ILS heading)
In the above example set the start location to the exact same runway heading (13th position). Set the plane up on the go to and slew back 20, 30 , 40, 60 Nm's and see where the Approach code ILS heading would position the plane vs your actual position. Change the runway heading to the tenth ( 70.3, 70.4, 70.5, or what ever you want) and see how much further away that tenth takes you in respect to the approach code ILS heading.
The actual heading bug is in ver 1.37 which we fixed in 1.40 by going from the tenth position to the .xxxxxx position. In Version 1.37 it is almost impossible to align the Start Location with the exact runway heading using the tenth position due to what happens in the BGLCompiler with all the other decimal positions FS uses.
We introduced the approach mode in Ver 1.40. The reason for the 6th decimal position is so the approach designer can set the missed approach turn for the AI/User Plane if the User elects NOT to use the published missed approach.
If you have no intentions of ever using the approach mode and don't care if the non-published missed approach is to the left or the right then set the runway True heading Base End to whatever you feel is correct (FS will set the recip based on magdec for KSNA) and ADE will handle the zero's.
Once you decide what runway heading you want to use to the (tenth position) then set the other related headings the same. At that point there is no guarantee’s what ATC will do with the non-published missed approach. The runway texture heading and center line carry an invisible alignment code that is not just the length of the runway but circles the entire globe (as per ACES).
Any kink in the FAF to the runway center line back to the "IF" leg Terminal_Waypoint vs the ILS Approach Code heading means we cannot set the non-published missed approach turn properly. I can understand that designers may not see the importance of at least 6 decimal places until they start adding approach code and working with the automated turn direction we introduced behind the scenes.
If the approach code heading for the ILS (non-weather related approach) is not the same as the runway heading + or - .2 (ADE spec) at 5 Nm's or 125 Nm's then ATC will not code the AI /User plane the way FS intended.
The runway heading is the key to all Approach code headings that get passed to the AI/User plane. If every runway heading in FS was only to the tenth position then we would leave it at that.
However in FS and ADE the tenth position is not the perfect runway heading (when there are 13 more places) so long as the FS world is populated with AI Planes.
