Come on.
And what about when flying in cruise and the airplane decides LNAV and heading mode are just gonna take a vacation. Cruising a good 5 hrs into the flight. Blehh Blehh Blehh as the AP kicks off. What happened? Somehow entered CWS R (control wheel steering - roll) for the lateral mode. AP gone.
Weird.
Try to re-engage AP. No dice.
Try to re-engage LNAV, no dice. Try to engage Heading, no dice. AP again, no dice. AP on CWS, no dice.
Ok. Flight Directors off. Lets put the master back on CA side. Now engage LNAV, VNAV, AP on. VNAV takes but no lateral mode. Still no Heading or LNAV. Still no AP. Ok, Flight Directors off again. Lets put FO side as master and put the FD on again. Re-engage modes. Lateral mode doesn't take. Still no AP.
AT stayed on whole time.
But! But! In slum's world, this situation can't exist. The AP and automation is supposed to always work.
End result, continued flight under manual control after discussion with dispatch. Frankly no mood to divert to a place neither had been to before (Managua). Not too far from LIB and familiar there with nice, clear VMC conditions.
And by the way, VNAV engaged, so had one pink magenta bar for following VNAV guidance, but nothing for LNAV. No lateral guidance bar. Used the wind vector, the track on the ND, and the heading bug to keep on course - all manually. You know, fly the damn plane.
Oh the manatee!
*MCP Lockout QRH was considered but the conditions listed in the QRH didn't match lockout. No CBs pulled.