Some airline personnel have contacted me since I started my petition saying “it’s not possible to have wheelchair spaces on aircraft. 
As this shows - airlines can but won’t - https://ergonomics.org.uk/resource/welcome-on-board.html

Aircraft these days have cabins complete with showers, sleeping pods etc but say they can’t have accessibility! That makes no sense.
United Airlines have the perfect opportunity next month to choose accessible features for their upcoming replacement aircraft. Thank You again for signing the petition.

Regards

Pekka