Originally, the consensus among core developers on the devel list was that
QT related functionality would have to remain entirely optional and that for any useful functionality, a "common service layer" would be used, so that a non-Qt front-end could be provided (e.g. using Phi, PUI, the console or Canvas):
viewtopic.php?f=71&t=25087&p=229303#p229303Torsten wrote in Thu Jan 08, 2015 10:40 am:There is currently heavy activity towards a new UI. There will be the HTML5 based version, I am currently working on and an internal implementation based on well supported libraries. Most likely, both will use a common service layer to provide necessary data.
Neither of those will use Nasal or Canvas to render the UI elements.
James stated that the Canvas based aircraft center was disabled to ensure that the Qt based re-implementation would get wider testing:
2018.3 ReleaseTo enable the original Canvas-based
Aircraft Center in non-QT builds, you will have to edit/patch menubar.xml or execute the dialog directly, e.g. via the Nasal console:
Reinstating Canvas based Aircraft Center for non Qt builds