I was flying QualityWing 757, and I decided to mess with the FMC after 3 hours of unsuccessful attempt at FMC with PMDG 747.Apparently my flight plan is already loaded into FMC, and I picked BAYPO1 from runway 36L for SID from Tampa airport, and activated it.The plane flew North to BAYPO, then turned to fly to the route according to the flight plan. Then I don't know what happened but the planejust started turning and turning and drew a couple big circles between the 2nd and 3rd leg of the route. I had to stop LNAV and switch backto GPS + approach hold + altitude + speed hold in order to continue the flight. Does anyone know what might've caused the FMC to jack up? I'm been having tons of problems with FMCs, it seems so difficult to useeven after 3 hours of video + PDF tutorials...

After selecting RW 36L and the SID BAYPO1 and activating it, you need to go into the LEGS page and look for any discontinuities (there will definitely be discontinuities - at least one). When you find one, click on the next waypoint down and then click into the place where the discontinuity exists. Look again on all pages of the LEGS page and make sure there are no more discontinuities. Activate again and you'll have a smooth flight down to the glidepath where you can then turn on APP and come in for a very smooth landing. Keep your patience with the FMC. They are really and truly simple to use once you have programmed one or two flights. Best regards,Jim

Thank you, good sir. I'm getting better with FMC now. I just managed to put a PMDG 747 onto route, and I feel accomplished lol.

Thank you, good sir. I'm getting better with FMC now. I just managed to put a PMDG 747 onto route, and I feel accomplished lol.

That's great news! Once you set the arrival runway and SID, fix the discontinuities in the LEGS page, and reactivate, don't forget to set the Speed and Flaps settings. If you haven't been doing this, click on the Init Ref Page on the FMC, and look over to the right side. You should see the FMC is predicting an airspeed of around 150KTS with Flaps at 40 (this could be higher/lower depending on weight of your aircraft). Click on the button next to the 40/150KTS and enter it below in the blank space. You have now told the FMC your landing speed when the flaps are lowered to 40. To me, it's amazing how accurate the developers have programmed the FMC to simulate real world settings. Enjoy!Best regards,Jim