[avs733]

ultrasound works quite well as well - but no NRE technique is perfect

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7503374/

[eternityforest]

Didn't they specifically refuse to do any testing because they trusted that proprietary acoustic system?

[thsksbd]

The paper is from 2020. My understanding is that composite testing is still in its infancy.

Also note that the hull was 5 inches thick (safety factor > 2.5). Depending on the dispersion properties of the medium ultrasound might not penetrate and get a good result. In Ti (some alloys at least), for example, you cant get much signal past a couple of inches due to the scattering (from the grains?)

[namibj]

That was supposed to hear the hill cracking/creaking.

Ultrasound for delamination is like medical ultrasound and looks for a discontinuity in the sheet from the delamination.

[eternityforest]

I think someone wanted to do the delamination hull scan and they skipped it presumably because they trusted the creak listener