Control Plan (AS9145)

01 Purpose & why a composite part needs this document

A machined metal part can largely be inspected after the fact — its geometry is set by cutting, and what was cut can be measured. A composite panel cannot. Its most critical properties — cure quality, void content, porosity, ply orientation, bond integrity — are created inside an autoclave and cannot be restored by rework once they are wrong. That single fact drives this entire plan: for a composite structure, quality is built in during processing and can only be confirmed afterward, never added. The Control Plan is where that principle becomes specific — it names each characteristic, ties it to the process step that creates it, and states the control that keeps it right the first time.

The plan is organized around a distinction that governs everything downstream: the difference between a characteristic verified after processing and a process parameter controlled during it. A wing panel's hole positions can be measured on the finished part; its cure quality cannot — by the time the part exists, the cure is history. So the plan controls both, differently, and says which is which.

Where the Control Plan sits in AS9145

AS9145 structures product quality planning in five phases — planning, product design, process design, product & process validation, and ongoing production with feedback. The Control Plan is the artifact that carries forward from process design into validation and then governs ongoing production; it is not a document written once and filed. It is established during process design, validated at First Article Inspection, and then becomes the living reference that production runs against. On the CWP-700 that lifecycle is visible in the program's own milestones: the Control Plan's characteristics are what the First Article Inspection (accepted 25 Sep 2026) ballooned and verified, and Production Release Authorization (11 Nov 2026) is the point at which the validated plan begins governing full production. The plan a reader sees here is the validated plan — the one that survived FAI and now controls the line.

02 Characteristic classification & what it decides

Every characteristic on the drawing falls into one of three classes. The class does not decide whether a characteristic is verified — every characteristic is verified — it decides how intensively, and whether control happens on the finished part or inside the process.

Where Key Characteristics come from — and why the classification isn't Acme's to invent

Key Characteristics are not chosen by the manufacturer for convenience. They are identified from Meridian's engineering source data — the drawings, specifications and stress analysis that define which features carry load, mate to the airframe, or affect flight safety. Acme flows those down into this Control Plan; it does not originate them. That direction matters: a manufacturer that reclassified a customer's Key Characteristic as standard in order to sample it rather than inspect it 100% would be substituting its own convenience for the customer's engineering judgment about what keeps the aircraft safe. The Control Plan records the classification so that this boundary is explicit and auditable — a Key Characteristic is a Key Characteristic because Meridian's engineering says so, and the plan traces back to that source rather than asserting the classification on its own authority.

03 Where each control sits in the process

The Control Plan maps to the manufacturing router. Reading left to right is reading the panel being built — and it shows why control has to be in-process: by the time the part reaches final inspection, four of the five critical process parameters are already locked into the laminate.

04 Key Characteristics (6 — 100%, never sampled)

Key Characteristics are verified on every panel, for the life of the program. They are the characteristics whose variation reaches fit, structure or safety, so the sampling transition that applies to standard characteristics (§06) never applies to them — not in Phase 2, not at full rate, not ever.

05 Critical process parameters (5 — 100% of cycles)

Critical process parameters are not measured on the part — they are controlled while the part is being made. Each is recorded automatically for 100% of cure cycles, with an alarm on any excursion beyond the qualified process window, because an excursion that is not caught in real time cannot be caught at all: the laminate has already cured around it.

06 Standard characteristics & the sampling transition (3)

Standard characteristics are real drawing requirements — I-01 proved they can stop an inspection — but their variation does not reach fit, structure or safety. They are the only class eligible for the sampling transition: verified 100% in Phase 1, then sampled once the process has demonstrated capability on them.

07 Standards & ownership

The Control Plan is governed by the aerospace quality standards the suite already operates under, and each characteristic class has a named owner accountable for its control.

08 How the classification governs nonconformance disposition

The characteristic class does more than set inspection intensity — it constrains what can be done with a part when something goes wrong. When a nonconformance is found, the Material Review Board dispositions it, and the Control Plan classification is the first thing the MRB checks, because it determines which dispositions are even available.

09 How this plan is used across the program

The Control Plan is not a standalone document; it is the hub several other artifacts point at. It is the baseline the Inspection, Test & Verification Strategy flows down from (§05), the characteristic list the First Article Inspection balloons and verifies (AS9102), and the reference the Material Review Board uses to judge whether a nonconformance touches a Key Characteristic — the classification that determines whether a disposition is even eligible for use-as-is. When Meridian's engineering source data changes a characteristic, this plan is where the change lands first, and the router, inspection sheets and FAI follow from it. That is what makes it the program's requirements baseline: it is the single enumerated list of what the part must be, against which everything else verifies.