Originally Posted by
jaja
A321 neo & ceo have very different flare laws :
A321ceo
When the aircraft passes 50 ft RA, the THS is frozen and the normal flight mode changes to flare mode as the aircraft descends to land. Flare mode is essentially a direct stick-to-elevator relationship (with some damping provided by the load factor and the pitch rate feedbacks).
The system memorizes the aircraft's attitude at 50 ft, and it becomes the initial reference for pitch attitude control.
As the aircraft descends through 30 ft, the system begins to reduce the pitch attitude to -2 °nose down over a period of 8 s. Consequently, to flare the aircraft, a gentle nose-up action by the pilot is required.
A321neo
When passing 100 ft RA, the THS is frozen and the normal flight mode changes to flare mode as the aircraft descends to land. The flare mode is a direct stick-to-elevator law without auto trim, with some damping provided by load factor and pitch rate feedback. The flare law provides full elevator authority. The flare law does not compensate the ground or thrust effect.
Ah perfect. Makes sense now. Thank you!
Originally Posted by
The Scarlet Pimpernel
Jeepers - some people do make things very difficult. Technically there are differences, but there are so many other variables day-to-day, are you really going to notice? As compressor stall said, the TPs at Airbus have done a great job in smoothing out the different control laws to make them all very similar. There are different laws in take off also between the Neo and Ceo but you'd never know. FWIW I fly most variants of the A320 from knackered old sheds to brand spanking new. The last thing on my mind at 50ft is whether the THS has been frozen by a control law on a particular variant. To the OP, yes there are differences between the Neo and the Ceo.
I think it's still important to know wth the plane is doing at all stages of the flight. We remember what happened when MCAS was omitted from the MAX FCOM, right?
Originally Posted by
compressor stall
Yes, but the comment above was from one of the orange suited guys at the conference Q&A session. IIRC it was in answering an audience member (airline tech pilot) who had done some digging deeper than the A320 NEO/CEO FCOM and found some differences.
In some of the new FCOMs for the CEOs, I find that they're no longer mentioning the whole -2° in 8 seconds thing when they're explaining flare law, and that's why I asked here. I tried to do my own digging but came out even more confused. But it's good to see that they try to make the aircraft the feel the same throughout its evolution, although it's probably a regulatory requirement lol