Answer:
X-ray and Backlighting
Explanation:
Fiberglass/honeycomb structures can be possibly inspected for entrapped water either by Backlighting or X-ray method.
The Backlighting method of inspection is carried out by removing all the surface paints and beaming a strong light on just one side of the panel whilst examining from the other side for any dark areas that would give an indication of entrapped water.
