Originally Posted by
OnceBitten
I don’t want to get technical but there’s a couple of errors that you could drive a truck through on that video above that stands out;
1/ Flight directors initially command 8 degrees nose up through the take off roll and command a pitch angle based on speed after rotate. E.g V2-V2+15. The flight directors are independent of MCP setting and they do not sit at zero during initial take off as alluded to.
2/ The Flight director pitch angle wouldn’t/ should not changed after take off until VNAV automatically engages at 400ft if armed or another mode was manually selected prior to this point.
I think there might have been a bit more that went on other than what this very basic video has concluded, Be fair to the crew and let the investigation run its course.
My understanding is that if the MCP Altitude Window showed 0000 when the F/Ds were first selected ON, then the active modes would not be TOGA TOGA (as is normal) but TOGA ALT (which is obviously not normal) assuming the aircraft elevation was within the altitude capture parameter, otherwise the default mode of V/S, which would be zero or TOGA. Either way, subsequently setting 4000 feet (SID Stop Altitude) into the MCP Altitude Window (even if it was set) would not change the active mode from ALT or V/S in this case. The F/D would therefore 'Direct" a pitch attitude to maintain level flight unless or until another Pitch Mode was selected as, clearly, TOGA was not the active Pitch mode.. It does beg the question though of why oh why did the PF just not rotate to something like 12-13 deg nose up (heavy aircraft) and just FLY THE AIRPLANE?
Hopefully, lessons learned and if crew have been fired, just be thankful that they (and all their pax and people they flew over at VERY low altitude) are still alive.