Aftermarket glossary

The terms that come up every day in parts sales, repairs and purchasing — explained in plain language.

Operations

AOG (Aircraft on Ground): An aircraft that can’t fly until a part or repair arrives. AOG requests are the most urgent in the aftermarket, and response time often decides who wins them.
MRO (Maintenance, Repair and Overhaul): The organisations and work that keep aircraft, engines and components airworthy — from line maintenance to full component overhaul.

RFQ (Request for Quotation): A buyer’s request for price, availability and lead time on a part or a repair. On Avilinkr, priced stock can be ordered directly; anything else becomes an RFQ.
Aviation aftermarket: The market for parts, repairs and services that support aircraft after delivery, as opposed to building new aircraft.

FAA Form 8130-3: The FAA’s authorised release certificate, confirming a part conforms to its approved design and is in a condition for safe operation.
EASA Form 1: The European authorised release certificate, issued by an approved organisation when a part is made or maintained.
PMA (Parts Manufacturer Approval): An FAA approval that lets a company other than the original manufacturer make and sell an approved replacement part.
Traceability and trace pack: The documented history of a part, from manufacture through every owner, repair and release. Buyers expect it before they install.

Condition codes (NE, NS, OH, SV, AR): New, new surplus, overhauled, serviceable and as removed. The code describes a part’s state and strongly affects its price and who can use it.
Serviceable: A part inspected, repaired or tested by an approved organisation and certified fit for installation.
Exchange unit and rotable pool: A serviceable unit supplied straight away in return for the customer’s removed unit (the core), usually for an exchange fee plus the cost of repairing the core.

Alternate part and supersession: An approved substitute part number that can be used in the same position, or a newer number that replaces an old one.
ATA chapter: The standard numbering that groups aircraft systems — chapter 32 is landing gear, for example — used across manuals, inventory and reporting.

Turn time (TAT): The time from a unit arriving at a repair shop to it being released back to the customer. Often a contract term with penalties attached.

We’ll walk through it in Avilinkr with you, on your own data, in 30 minutes. No obligation.