It’s been quite some time since I’ve flown in IF, so maybe I’m missing something obvious. I’m currently doing a long flight from Los Angeles to Dubai. I’ve set to cruise at around FL380, upon my climb I encountered a random, rapid descent. I disengaged the AP, hand flew it to recover, and reactivated my AP with a lower altitude now (FL320). Roughly a few seconds later I began to rapidly descend and “sway” back and forth once again. Any ideas?
Update: I’ve now noticed that the obsessive banking and attitude fluctuations occur upon reaching my selected altitude while in AP mode. If I have just my VS selected, it doesn’t appear to encounter any issues—-only when I have my altitude bugged in
This has happened for me before, It could be due to a Heavy weight, Which causes the aircraft to sway side to side like that. for 8hr+ Flights I recommend stay between FL320 and FL360 just to be cautious.
I was thinking that, but it doesn’t quite explain why it ONLY occurs when I bug my altitude. When the AP is off, it flies normally. When the AP is on (only without the altitude set)and climbing only via VS, it operates fine.
Yeah u don’t want to immediately go up to FL380. You’re too heavy. Start at a lower altitude (I’d recommend FL300 or maybe even 280 if going westbound) and step climb as u lose weight - so like every 3 hours maybe climb 2000 ft
The AP will start to panic at the edge of the performance envelope. If you’re an A380 you’re almost certainly too high (I think near MTOW the max is 350 and even that is slightly pushing it). It overreacts to the high AoA which causes small swaying which it overreacts to again until you flip over and dive.