Non-destructive evaluation has three major functions for research, dev
elopment and applications testing of fibre-reinforced composite materi
als and structures: initial inspection of test specimens and confirmat
ion of the structural integrity of new components monitoring laborator
y tests in progress and evaluation of components subjects to service l
oads analysing test results after failure and proof loading of compone
nts during their service life. The paper reviews the defects which are
likely to occur during the manufacture of such materials, and conside
rs the criticality of the defect which may need to be detected. The im
plications of material inhomogeneity and anisotropy are examined in th
e context of non-destructive testing techniques.