Historically: Tagging, especially "yellow tag," is a term used in US aviation to indicate a part is serviceable and airworthy as evaluated by an FAA certified repair station. It is important to note that this term is an industry term and is not an FAA requirement or even mentioned in the Federal Aviation Regulations. Red Tag: component is scrap or unusable Yellow Tag: component is serviceable and airworthy Green Tag: component is not airworthy but is repairable
Today "yellow tag" is a meaningless term, in that it can mean anything the person filling out the tag says.
An overhauled and certified part today requires an FAA 8130-3 Airworthiness Approval Tag which serves as approval for return to service after maintenance or alteration by an authorized Part 145 Repair Station, or a US Air Carrier having an approved Continuous Airworthiness Maintenance Program.
Basically, as a certified mechanic installing a part/component on an aircraft the 8130-3 is your approval to install the part.
More: The term “yellow tag” is colloquially used in the aircraft industry, but it has no real formal meaning or value as to parts serviceability. Many serviceable repaired or overhauled parts are returned from Repair Stations with a yellow coded tag, but a close inspection will reveal that the tag is labeled as FAA Form 8130-3. A rejected or non-airworthy part may be “red tagged”, but will not have the FAA Form 8130-3 release. Without the FAA Form 8130-3 attached, the aircraft part is not suitable for installation. The FAA Form 8130-3 ultimately becomes part of the maintenance record of the aircraft to prove the “chain of approval” of the airworthy part.
FAA Form 8130-3 is a dual use form. It can be used to identify new manufactured aircraft components to be shipped both domestically and internationally (Authorized Release), and is used by FAA approved Repair Stations to certify repaired or overhauled status (Airworthiness Approval Tag). The legal document regulating the use of FAA Form 8130-3 can be found in 14 CFR FAA Order 8130.21.
