Do you know the weight of the aircraft? From what is being described, it sounds like a combination of strong headwinds and heavy aircraft weight.
It’s at a 73% load.
If the winds are strong, you will get some movement like he said.
And roughly how long are you intending to fly for?
6 hours. KLAX-PHNL
You were to heavy at FL400, when you are this heavy, don’t go straight to cruising altitude, start at a lower and work you way to final altitude.
check your weight and balance, and descend to FL370 or lower
As said above you are quite heavy and quite high, see below here is an IRL representation of the altitude a typical A321 would fly at for this route, hope this helps! :)
Obviously we aren’t able to tell the cargo weight and the passenger weight, but this is just a rough example.
(on this particular flight the pilots did a step climb from FL320 up to 340 passing through 330)
The A321 is known for bobbing and rocking all over the place even with perfect variables and levels - it needs to be reworked a bit.
The A321’s service ceiling is between 39,100 and 39,800 feet according to Wikipedia, ie 40k ft is too high. But nevertheless, the question is whether the oscillation is necessarily coming from too little speed. At 38-40k ft altitude, I would risk stalling and check what would happen once you slow down a bit to Mach 0.78 or less. This way, you will know for sure how to solve these kinds of situations once and for all. Generally, looking up these crucial bits of data (rotation speed, landing speed, service ceiling) is always a good advice 🙂
Source: Airbus A321, on Wikipedia
i have never known the A321 to bounce around unless there is turbulence
do keep in mind that this is a medium-haul narrowbody airliner, not a 787, and should be flown as such
A321 is my scene in order for you to do 9️⃣ hours flight ✈️ or even 1️⃣ 0️⃣ you need to start in the absolute minimum(FL280). Full tanks and make sure your payload it’s not that much I would recommend no greater than 2.5, if you want to carry a full pax(like I do) it decrease your range.
Transatlantic flights are a nightmare make sure you always check the weather condition before you start your journey. Again if you want range avoid using oceanic tracks for i.e. I usually do STN-LAX with a321 it is impossible using the oceanic track due of the strong winds 💨 consume a lot more fuel. I Go over Iceland 🇮🇸 and then Canada 🇨🇦.
The more you fly ✈️ with a321 the better you will manage the A/C. I have reached the west coast of the United States 🇺🇸, I have been to Brazil 🇧🇷, China 🇨🇳, Maldives 🇲🇻, south Africa 🇿🇦, India 🇮🇳.
You can don’t too, once you know the A/C
On this kind of flight I would start of at FL320 and make my way up to 380. Also the maximum for the A321 IRL is M. 82, I suggest slowing down to below 80 for a smoother ride. Hope this helps!
Edit: Westbound so FL320/340.
I’ve flown the A321, never stalled it. I always go VS: 3000 per minute, then go match 0.86 at cruising speed. I can help more if you ask.
Its a bug on the 321 that occasionally happens.
There is no way thati have found to fix it
Also you are too high, do altitude 34,000 FT
Too fast. The best speed for the cruise is .84 or .82 you will have no problem
A long flight? From 8 to 10 hours?
Considering the fact that the A321 has 3200nmi range that equates to about 8 hours of flight time I wouldn’t go over 7 to be safe. On heavy flights you must start at a lower altitude or you’ll stall. Also M. 78-79 is normal for A320 family, 737 etc.
still too fast, A32X family cruises at M.78 to M.80