We get audited fairly often, and over the years we've noticed that the buyers who really know what they're doing all look at the same handful of things, and certification is rarely one of them. Not because it doesn't matter. AS9100D is the minimum, and earning it takes real work. But it proves a shop built a quality system and passed an audit on it, not that the system gets used on an ordinary Tuesday. Two shops with the same certificate can be very different suppliers, and here's where that difference shows up:
- How fast traceability works. Every certified shop claims it can trace a part back to its material batch, operator, machine and inspector. What varies is how long it takes. Pick a part off the dispatch table yourself and ask where the material came from: minutes means it's a living system, an hour means it's a filing cabinet.
- The work that goes outside. Almost nobody does their own heat treatment, plating or crack testing. A part is only as approved as the weakest link in that chain, so a perfectly machined component that went through an unapproved plating line isn't an aerospace part. Ask for the subcontractors' current approval certificates. Either the file appears, or you get told the plating company is very good and has been used for years.
- The inspection room, not the machine list. An instrument should be roughly ten times more precise than the tolerance it checks. Look for calibration traceable to national standards and a rule that pulls overdue instruments off the floor whatever production wants. The check everyone skips: whether two inspectors measuring the same feature get the same answer.
- What happens when the drawing changes. Every programme has revisions. A shop with control knows which revision each job is built to, has a set way of stopping and re-issuing, and knows when a change needs a fresh first article inspection. Ask about the last change they actually received, not the written procedure.
- What happens when a part is bad. Every shop eventually makes one. Is it separated immediately? Is there a clear route to ask the customer for a concession, or does it get quietly reworked and shipped? The answer matters less than whether they're comfortable having the conversation at all.
- The first article package. Every dimension numbered on the drawing, every one measured with a real figure rather than just "pass", certificates attached. Ten minutes reading one tells you more than a full tour of the floor.
- Records and housekeeping. Aerospace contracts want records kept for decades, and shops move premises and change hands. And loose debris sounds like tidiness with a technical name, but shops relaxed about swarf are usually relaxed about other things too.
Certification gets a supplier onto the list. What keeps them there is whether the system behind it works: traceability in minutes, honesty when something goes wrong, real control over the work sent outside, and measurement worth trusting. All of it is visible in a single visit. The buyers who get the most out of one are simply the ones who know that.