Problem With The FMC

[Spin737 102]

What's depicted on the legs page doesn't even come close to matching the SID. It's no wonder the FMC won't follow it.

[Eyal Maoz 0]

Ok so how can i fix it?

[ronzie 21]

I set up a quick flight plan from LLBG heading west and ACT and EXE'd it but using NAT3F as shown here. The aircraft is sitting on RWY30 and the ND range is set to 40 so it shows the path all the way out of ATIT and then ERXE'd it:Here is LEGS1:and LEGS2:then closing the DISCO and EXE'd the change:From a late 2007 AIRAC here's the data for NAT3F and NAT3FS:SID NAT3F RNW 30 TRK 298 UNTIL 535 TRK 254 UNTIL 2.2 FROM FIX BGN TURN LEFT DIRECT FIX BGN FIX KANER 4000 FIX NAT TRANSITION ATLIT FIX ATLIT TRANSITION DESHE FIX DESHE SID NAT3FS RNW 30 TRK 298 UNTIL 1.5 FROM FIX BGN HDG 214 INTERCEPT RADIAL 265 FROM FIX BGN TURN LEFT DIRECT FIX BGN FIX KANER 4000 FIX NAT TRANSITION ATLIT FIX ATLIT TRANSITION DESHE FIX DESHE Note the ND display in each case. The last image shows the plan.Your LEGS1 page shows climb at rwy heading to 534, then direct BGN which is incorrect, then intercept R254 of BGN which is correct, then back direct to BGN which is incorrect, then to MESIL which is not in my procedure data, then correctly to KANER, NAT, and ATLIT and then to your route waypoint.Rather than a screen shot, can you open your LLBG.txt file in your PMDG/SIDSTAR folder in wordpad or notepad and copy the lines for NAT3F through the end of NAT3FS in a reply here?I hope this give you a clue. Perhaps your flight plan already had some kind of SID waypoints in it when you added the FMC SID and things got messed up.

[ronzie 21]

I zoomed in to the path from the intercept BGN-2 and the instruction for a left turn is not being followed in the display:SID NAT3F RNW 30 TRK 298 UNTIL 535 TRK 254 UNTIL 2.2 FROM FIX BGN TURN LEFT DIRECT FIX BGN FIX KANER 4000 FIX NATat least on the ND.So not fixed. Since the aircraft can not turn that sharp I'm not sure how it will turn but if it takes the shortest path it might turn right instead of left on LNAV.MESIL is direct on the path to NAT and is an update I don't have.I messed around with the code but no improvement in the display. As was stated as you fly and the altitude and present position changes maybe it will follow the correct left turn.Sorry for misleading you.

[Eyal Maoz 0]

Allright but i didnt understand what i need to do with that?In my last post you can see the LEG page and there is no DISCO there. So what should i do?

[Spin737 102]

I think the SID isn't coded correctly. It's not something in the FMC that's wrong - it's software issues. I don't know how to fix it, sadly. That's beyond my pay grade.

[ronzie 21]

I recoded the NAT3F with creating an additional intercept that would require a left turn and took out some of the code. On the ND I see a white hollow circle showing the intercept (radial from the VOR) put the displayed path will not go through it. I creates an additional leg with a right turn instead of left. What is interesting on the LEGS page it shows the correct bearing that I programmed to this new radial/dme intercept, less than a ninety degree turn to this added soft waypoint.Will the path displayed have an AGL limit before allowing a certain turn but the LEGS page not reflect that?I did this sitting lined up in front of the threshold at RWY 30.