It is impossible that your QC did a thorough check, like you mention in your mail. Otherwise, they would have rejected around 80% of the handrails. The design of the handrail was setup in a good way, also with good tolerances mentioned on the drawings.This morning Gavin confirmed that the supplier had told FTBCI that he was unable to make the handrails according the tolerances. This already indicates that your QC has accepted handrails which should have been rejected. On top of that, your supplier indeed made a few well-functioning handrails, from this we may conclude that it is a quality control issue of the supplier and does not necessarily mean he is not able to build a decent handrail. If I am correct, then you have had a meeting on this topic with Christina and Gavin already. I have attached the mail which I have send to them earlier this week. Looking at these pictures we may conclude that the handrails are not build according the specifications that FTBCI has send to the supplier. Based on this information your QC should have rejected non-conform handrails. Please coordinate corrective actions as soon as possible and keep us updated on the progress.