Moulting quaker parrot

Unbelievalbe!!! I never experienced this before... moulting quaker parrots. Pfff.. as you know Paulie was troubling with a very bald neck. Now we know it was the moult.. he got new feathers, but still has a spot which is totally bald. Today... Mr and Mrs Quaker came out of there cage and Blue wanted to "fly away".. Wham! On the floor!! (didn't you experienced this Conny during my vacation?). I thought... why is that?? not normal. I let her step up and looked at her closely. ALL THE PINFEATHERS from her left wing were gone!!! Wow.... looking more closely I saw new pin feathers coming back, thank god. But I really never experienced this before, having birds. Who has experience with this kind of moult??