Xanadu 16 YMML Blunder
Post-flight, it was determined that altitude (ALT) mode was selected on the autopilot. This caused the aircraft to level off and accelerate. The crew were not aware of this at the time. It is suspected that the captain inadvertently pushed the ALT button which was not detected by the crew.
Not rated on the 330 but perhaps someone who is can explain how one selects “ALT Mode” by pushing a button?
This is independent of whether you are in manual flight or auto flight.
COMMANDS here would mean directs via flight director in manual flight, or indeed AUTOMATICALLY follows the guidance when Autopilot is selected. The Flight Director does work in both manual and auto flight regime.
Mode awareness and indeed the status of the autopilot would appear to be contributing factors in this event.
It is possible it took a while to connect the dots and come to the realization that nobody, nor the autopilot, was flying the aircraft.
Why would you expect otherwise?
So you can use it appropriately should you wish. At 400' all engines, probably not but it was inadvertent.
i’ve now looked it up and see there is an additional button on the A330 FCU for engaging ALT mode, like I say different.
cheers
Here is someone who has no experience with an autopilot other than the one on the A320! No offence intended, StudentInDebt, but the A320 autopilot panel is quite unusual in not having an ALT button. The ALT button is similar but not identical to pushing the VS knob on the A320. ALT hold captures an altitude rather than just targeting a VS of 0.
Here is someone who has no experience with an autopilot other than the one on the A320! No offence intended, StudentInDebt, but the A320 autopilot panel is quite unusual in not having an ALT button. The ALT button is similar but not identical to pushing the VS knob on the A320. ALT hold captures an altitude rather than just targeting a VS of 0.
As I say, having realised I was missing something, I looked up the answer online myself which then complemented the explanation t_cas gave, and indeed your own once you got the condescension out of the way.
Last edited by StudentInDebt; 12th Mar 2019 at 06:07.
If they did in fact retract all the flap (as indicated in the first post) then re-selecting toga after that will not give a mode change (srs/ga trk or nav) it will just give toga.
Right, yet they over sped the flap? That wouldn't have happened in CLB detente as it'd be a managed speed target.
So is it safe to assume old mate retracted flap, then immediately selected TOGA (which it would seem works only on flap lever position, not flap actual position), thus negating SRS, yet received the overspeed (which works from actual flap position).
Sound about right? Trying to get my head around it.
So is it safe to assume old mate retracted flap, then immediately selected TOGA (which it would seem works only on flap lever position, not flap actual position), thus negating SRS, yet received the overspeed (which works from actual flap position).
Sound about right? Trying to get my head around it.
Without going into the manuals, that's my understanding. Having prematurely selected 'ALT', SRS is de-activated. You can't go back into SRS; the only way to resume the climb would be to "ALT-PULL" into Open Climb, and select an appropriate speed (V2 + 10 etc). Or fly the windshear escape manoevre
'Deliberate Action' and FMA confirmation lacking.
'Deliberate Action' and FMA confirmation lacking.
