While we recommend users use Aircraft Profiles to drive downstream events like work orders, this isn't always the case and sometimes a user may have "stray" work orders they'd like to tie back to an Aircraft Profile.
To link a work order to an Aircraft Profile, simply navigate to a profile and scroll down to the "Work Orders" section. Here you will see a Tab marked 
:
Select the appropriate work order you'd like to link and it will now appear in the work order section for that Aircraft Profile.