Originally Posted by
Mechta
To meet the MAA requirements for accessibility and inspection of control linkages perhaps? The elevator bellcrank on a lot of gliders is completely out of sight if there is no inspection window.
I've seen a few gliders with inspection windows in the underside of the wings but never the tail end of the fus.
Yet another reason to put them on the G-register rather than cut additional holes in the structure which in itself will generate a pile of paperwork.