D, Shift+D, Ctrl+D toggle the various doors.
F toggles the cowl flaps.
Y toggles yoke visibility.
and these common aircraft keys are now implemented:
Ctrl+A: altitude hold (if pitch hold is already on)
Ctrl+H: heading hold (if wing leveler is already on)
Ctrl+P: pitch hold (if wing leveler is already on)
Ctrl+W: wing leveler.
These keys are toggles, as expected, but they also enforce the invariants:
Turning pitch hold off will also turn altitude hold off.
Turning wing leveler off will also turn everything off.
