Headings Keep Getting Flipped Around

[dracer33 0]

I'm not sure if that would be considered the correct way to spit that out but heres my situation. Im flying the SUMMT5 dep out of KATL. The plane flies the route on LNAV just as it should unitl we get near VXV trans. We started turning circles around the route, and I cant figure out why. So just for kicks and giggles I program the FMC direct BUGME (next waypoint) and lone behold it does it again. So I was watching the nav display closely this time. After the plane flips around 180 degrees we get near BUGME again the headings flip around 180 degrees out of the blue and the plane starts its 180 degree turn again. Anyone else know what I'm doing wrong or have this problem.

[NoahBryant 26]

Devin - You are verifying the LEGS page with the actual chart prior to departure right? Sometimes the database can have an erroneous way point stuck in there that causes the plane to do something like you describe.

 

Has this happened to you more than once?

 

Also, you say it's starting a 180 degree turn, so did you by any chance let it turn just to see what it's doing? You probably interrupted the turn and manually flew it to where it was supposed to go but I would be curious what the plane would have done if you just let it do it's thing.

 

Which AIRAC cycle do you have installed?

 

PS it's "low and behold" not "lone behold" :smile:

[dracer33 0]

No I let it complete about 3 of the turns, and I saw what it was doing. I watched the navigation display and literally the entire map, headings, waypoints, and all just flipped 180 degrees and the plane started turning. I've done countless flights with the 74 and haven't ever seen it do this. Also it was out of the DP after i turned direct BUGME. If you let it keep going it just turns back around, and when the plane gets a certain distance from the waypoint the entire nd flips 180 degrees and the plane turns again. I'm also using cycle 1209

[dracer33 0]

Well I found the problem something got jacked up when I last installed the last AIRAC update problem resolved