A Certificate of Airworthiness is issued by the CAA on the say of the nominated Engineer under a Section L licence under BCAR's.
Under EASA the Certificate of Airworthiness is none expiring and is backed up by the ARC that is filled out by the CAMO and a copy is forwarded to the CAA for their records, this re validates the CofA which is invalid without it.
Military terms for a CAMO
http://www.maa.mod.uk/approvals/camo_approvals.htm
Which I would seriously doubt is an NCO
BTW, I am one
