I have been trying to create some sids for YBBN in Australia The FMC seems to have problems with the HDG xx UNTIL command and half the time will not track the HDG commanded but picks a heading of its own, often turning left when the heading command would mean a right turn (or vice versa). The error seems to occur with both the HDG xx UNTIL RADIAL and HDG xx UNTIL INTERCEPT. Example 1 - ignores the heading command but turns in the right direction Sid IBUNA1 for YBBN RW01 reads - track 016, after passing 600ft and BN vor turn right and track 030, at 3 dme BN turn right and track 180, crossing BN R-090 turn right and track 300, intercept and track BN R-286 to IBUNA. SID created as SID RW012.IBUNA RNW 01 HDG 16 UNTIL 600 NAVAID BN HDG 030 UNTIL 3 FROM NAVAID BN HDG 180 UNTIL RADIAL 90 FROM BN HDG 300 UNTIL INTECEPT 286 FROM NAVAID BN NAVAID IBUNA When you load and view the SID in the FMC it turns right but to to a heading of approximately 220 instead of 180, then makes the right turn correctly to 330 to intercept the 286 radial to IBUNA. http://forums.avsim.net/user_files/36891.jpg This is what it should look likehttp://forums.avsim.net/user_files/36892.jpgThe only reason I was able to get it right for the picture here was to add a fix another 8 NM along to 030 radial from BN. The FMC ingores this fix and then the SID is much closer to the real thing. This is not a workable solution as although it displays correctly on the FMC, when flying the sid, the extra FIX in the sid causes it to turn late and wide for the 180 HDG. In then heads straight for the HDG 180 R-090 radial intercept point at roughly HDG 200 then tracks right although not at the heading requried. Also when flying this sid the purple tracking line disappears and returns at various points on the sid. Example 2 - ignores the heading command and turns in the opposite direction Sid COODA4 (to sprat) - YBBN RW19 reads - track 196, at 7dme BN turn tight and track 330, Crossing BN R-220 turn right and track direct AMBLE, at AMBLE turn right to track direct to COODA, after passing COODA turn left to track direct to SPRAT SID created as SID RW191.SPRAT RNW 19 HDG 196 UNTIL 7 FROM NAVAID BN HDG 330 UNTIL RADIAL 220 FROM NAVAID BN NAVAID AMBLE NAVAID COODA NAVAID SPRAT When you load and view the SID in the FMC instead of turning right to 330 it turns left and tracks back about 020 to the airport then turns eventually turns to IBUNA.http://forums.avsim.net/user_files/36893.jpgThsi si closer but still has a problemhttp://forums.avsim.net/user_files/36894.jpgAlthough it looks a little odd during the turn it actually tracks as desired. The code I used was to generate this picture replaces "HDG 330 UNTIL RADIAL 220 FROM NAVAID BN" with "FIX CJB1". Fix CJB1 is a point located where you intercept the BN 220 radial and turn from heading 330 to track direct to navaid AMBLE. This makes the FMC track correctly but why does the heading command have to be removed to get it to turn right? These are just two of the sids I have had problems with. Some others have also proved to have problems when trying to use the heading command and others work OK. Is this a bug in ther FMC or am I using the wrong syntax? Thanks

#1... well, you hit a limitation... As you see equivalent of turn left right HDG does not include some radius to have the AC turn...#2 is a bug in the intercept maths, which is now corrected and will be available with SU2.anthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com

Thanks AnthonyI look forward to the patch release as I understand it not only fixes bugs but adds new functionality.Does the current SIDS syntax support any speed restriction function? YBBN SIDS have a 240 speed restriction in some turns.Regards

Chris,Su2 syntax will support speed restrictions.anthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com

Hi Anthony,I attach a Sids and Stars file for YBBN. I think you will like IBUNA1 and COODA4. Both seem to be close to what you need. Now I did not pay much attention to speed restrictions well knowing that it will be very easy when SU2 is released. Please note also that there is a problem with two other Sids i.e. ST-GEORGE2 01 and ST-GEORGE2 19 as well as with one star namely JACOBS WELL.ARIKI2. So I only neutralized them in the txt file attached. Time permitting I will look into these three also.Please tell me what you think about it. By the way what I did is simple: I took my PIC 767 sids and stars for YBBN and converted them with Terry's converter, then I edited the file and made some manual amendements.Michaelhttp://forums.avsim.net/user_files/37087.txt

Michael,My home airport being LSGG, I, hmmm, don't fly often Down Under...(although I've been there 6 times already !)...I'll check them out though some time in the future... ;-)G'day !anthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com

Anthony,Sorry, I should have addressed my reply to Chris instead. Nevertheless if you got time have a look at the sids and stars for YBBN.Michael