Apprentice question
Field check
Standard work. Do it right, keep moving.
Loose or proud liner pins can catch dirt and let liner lift in the airstream. Flatten/secure them and repair liner facing per approved liner adhesive/spec before inspection closeout.
['Internal acoustic liner has to stay tight to the duct wall. If grip pins or heads stick proud into the airstream, they can catch lint/dust and create a spot where liner starts tearing loose.', 'Reach the area safely, flatten/secure the pin heads as allowed, repair damaged liner facing with approved adhesive/coating, and verify no loose insulation remains in the air path. Replace badly damaged liner sections if needed.']