In flight, I disengaged both FDs and then the A/P with the button on the control wheel. However, VNAV PTH still continued to be annunciated on the PFD, the VNAV button was illuminated on the MCP and the vertical VNAV scale was also in view. The roll mode was blank. I realize that the AFDS on the NGX is a little different from the other Boeings, but is it normal to have an FMA annunciation on the PFD and the VNAV MCP light illuminated when neither FD nor the A/P is engaged? Could not find any information on this in the provided manuals. Thanks! Rushad Ed.

In flight, I disengaged both FDs and then the A/P with the button on the control wheel. However, VNAV PTH still continued to be annunciated on the PFD, the VNAV button was illuminated on the MCP and the vertical VNAV scale was also in view. The roll mode was blank. I realize that the AFDS on the NGX is a little different from the other Boeings, but is it normal to have an FMA annunciation on the PFD and the VNAV MCP light illuminated when neither FD nor the A/P is engaged? Could not find any information on this in the provided manuals. Thanks! Rushad Ed.

Sounds OK to me !

Been discussed at length...

Sounds OK to me !

No it's not ok. It's one of the most fundmental basics of AFDS that you can't have any active mode with AFDS off. It doesn't make ANY sense and is against system design and philisophy. Refer to FCOM for details or the other thread as the important excerts are in there. But to the OP, the BUG you see be fixed with SP.

It's Not oke !!! when the F/D A and B and the A/P A and B are OFF (no CMD or CWS mode) , all FCC's (Flight Control Computer) are OFF, so the FMA should blank. and all mode light's on the MCP should be off. If want to make sure the A/P is really OFF hit the DISENGAGE BAR on the MCP. Some time's the A/P disengage switch on control wheel could malfunction.