First Article Inspection for Undercarriage Parts
Share
A first production sample can look correct and still fail to support a production-release decision. Its dimensional report may belong to another drawing revision, its material record may identify a different heat, or a deviation may remain open. First article inspection works only when the sample, requirement baseline, manufacturing route and evidence package all describe the same controlled event.
This article focuses on that integrated decision. It does not replace the broader bulk undercarriage sourcing process, create design tolerances or guarantee future lots. A submitted sample, a reviewed evidence package and an authorized release are three different states; the record should show exactly when each state has been reached.
Agree the first article scope before manufacturing
Define the object of review before the supplier makes the sample. Record the purchase-order line, part number and description, application reference when required, and sample quantity. Attach or identify the controlled drawing, specification and note revisions. If the purchase requirement expects records beyond dimensions, list them by name rather than asking generally for a “full first article report.”
The purchase requirement
The agreed scope should state the production baseline used to make the sample: manufacturing process, tooling, production location, material source and any special process source that the buyer has made part of the requirement. This does not mean every organization must demand the same details. It means the parties should define which facts must remain stable for the approval to have meaning.
List the evidence expected for that baseline. Depending on the approved purchase requirement, the submission may include a ballooned drawing, dimensional results, material record, heat-treatment or coating evidence, process or inspection references, traceability, photographs, marking verification and packaging checks. Supplier guides such as the Xianhong first-article approval overview illustrate ways to connect controlled requirements, evidence and production release, but they do not impose a universal method or establish KTSU capability.
Name the review authority and the decision authority. They may be the same person under a buyer’s procedure, or different functions. Without a named authority, a signature can prove only that someone signed a page, not that the signer was authorized to release production.
What approval does and does not cover
Write the proposed release scope in plain language: one sample, a defined part and revision, a stated tooling and process baseline, and permission to proceed with a stated production stage or quantity. Also write the exclusions. First article approval does not prove every future unit, replace production controls, certify service life or accept unlisted requirements.
A signed cover sheet cannot approve a characteristic that was never included in the evidence package. Nor can it automatically cover a later lot made after a source, tool, process or drawing change. Keeping those limits beside the approval avoids turning a narrow decision into a lifetime endorsement.
Build a submission tied to one production baseline
Create a cover record before assembling attachments. Give the submission an issue date and revision. Every file should link back to the same part, sample and baseline. Do not merge the best-looking records from several samples into a single apparently complete package.
Drawing and process revision
Start with the drawing number and revision, then list the revisions of general notes and referenced specifications that control the sample. Record the manufacturing process, tooling identifier, production location and named source where the purchase requirement makes them relevant. If a tool was modified between machining the sample and taking a later measurement, that change belongs in the record.
Check attachment versions. A dimensional report revised after correction should not sit beside an obsolete ballooned drawing. A material certificate or process record from an earlier trial should not be reused merely because it carries the same part number. The submission index needs the file name, revision or date, and the sample or lot it supports.
Sample and material identity
Assign each submitted piece a sample identifier that appears on the physical tag or controlled photograph and on the dimensional report. Connect that identifier to the material heat or batch and the relevant process lot. If the report calls the part “Sample 1” while the tag says “FA-03,” document the mapping or correct the report; do not assume the names refer to the same piece.
An aftermarket sample checklist such as the Guanyu sample-approval guide provides an example of reviewing application, dimensions, identification and packaging together. Use it as a process example only. The buyer’s approved requirements determine which identities and checks apply to the actual undercarriage part.
Where photographs are required, show the whole sample and readable marking in context. Packaging photographs can demonstrate the submitted packing state, but they do not prove a future shipment will be packed identically. State the purpose of every image and avoid treating a photograph as evidence for an unseen dimension or material property.
Review dimensions and supporting records together
Review the package as a set of connected claims. The dimensional report answers measured characteristics. Material, heat-treatment, coating, traceability, visual, marking and packaging records answer different requirements. Passing one evidence domain does not fill a gap in another.
Characteristic coverage
Reconcile the ballooned drawing with the dimensional results. Every required characteristic should have an identifiable balloon or reference, explicit acceptance limit, actual value, unit and sample identity. Confirm that reported conclusions agree with the values and limits. If a feature was not checked, state whether the approved scope permits the omission or whether more evidence is required.
A report can show PASS on every listed row while omitting an interface dimension. It can also report a value from a different sample or drawing revision. Those are submission gaps even when the arithmetic on the visible rows is correct. Review the detailed report using a controlled method rather than copying its summary result into the first-article cover sheet.
The Dewin first article inspection guide is one supplier example that links a drawing, characteristic results, supporting certificates and a conclusion. It does not establish a mandatory industry form or aerospace requirement for an undercarriage parts purchase.
Material and process evidence
Check that the material record identifies the sample’s actual heat or batch and the required material designation. Where heat treatment, coating or another process record is required, connect the process lot and source to the same sample. A generic certificate carrying only a part description cannot close the identity chain.
Keep each conclusion narrow. Dimensional evidence does not prove material or heat treatment. A material certificate does not prove every drawing characteristic. A marking photograph does not prove traceability unless the mark is linked to the sample and relevant records. If the first-article scope includes visual, marking or packaging checks, record each result separately with its acceptance basis.
| Cover-sheet field | Required baseline or evidence | Observed submission | Status and required action |
|---|---|---|---|
| Part, order and sample | PO line, part number, sample S-01 | All attachments identify the same order, part and sample | Reconciled; continue review |
| Drawing and process baseline | Approved revision D, tooling T-07, stated process and source | Dimensional report cites revision D; process and source match cover sheet | Reconciled within stated baseline |
| Characteristic coverage | All required balloons with limits, actuals, units and sample identity | Balloon 24 absent from the dimensional report | Missing; supplier supplies result or authorized scope explanation |
| Material and process identity | Sample S-01 linked to material heat H-18 and process lot P-04 | Material record says H-18; process certificate says H-81 | Conflict; correct identity chain before release |
| Nonconformity and release | Every nonconformity closed by correction or authorized deviation | Deviation request exists, but authority and scope are blank | Open; no release until authorized disposition is recorded |
This cover and release record should point to the original attachments rather than replace them. It makes normal, missing and conflicting states visible and gives the decision authority a reproducible path through the evidence.
Close nonconformities before release
For each nonconformity, record the exact requirement, observed result, affected sample and evidence file. Then distinguish correction from acceptance. Rework followed by a conforming remeasurement is different from an authorized decision to accept a deviation.
Rework evidence
A rework record should identify what changed, who performed the work, when it occurred and which process or instruction controlled it. The new measurement must identify the same sample and characteristic and preserve the original result. If root-cause analysis or corrective action is required by the purchase agreement, link that record without treating it as a substitute for the remeasurement.
Supersede obsolete evidence visibly. A corrected report needs a new revision or issue date, and the cover sheet should identify which file it replaces. Do not delete the prior report from the decision history. The reviewer needs to see both the original gap and the evidence used to close it.
Authorized deviations
A deviation should name the authorized approver, affected requirement, part, sample or quantity, scope, expiry or one-time limitation, and any conditions. A verbal acceptance or unsigned email thread does not permanently change the drawing. If the deviation applies only to the first sample, it cannot be silently extended to serial production.
Leave release status open until every required nonconformity has a recorded disposition. Approval may be full, conditional or denied according to the buyer’s procedure, but the language must state the actual scope. The article cannot assign deviation or release authority; those roles come from the order and quality agreement.
Decide when a new review is necessary
First-article approval belongs to a defined baseline, not to the part number forever. Before release, record which changes require another review and whether the repeat covers the complete submission or only affected characteristics and records.
Process, source or design changes
Potential triggers include a drawing or design revision, material or material-source change, new or modified tooling, changed manufacturing process, different production location, changed special-process source, a long production interruption, or a quality escape that calls the approved baseline into question. The applicable triggers must be agreed for the order; a supplier blog cannot define them universally.
For each trigger, name the notification owner, required evidence and decision authority. A drawing change affecting one feature may justify a partial repeat under an authorized plan, while a process relocation may require a broader review. Do not assume the scope. Record the rationale and the new baseline revision.
The release record should finish with the approved part and revision, sample identity, production baseline, attachment versions, closed deviations, release scope, decision authority and retrigger conditions. That is the boundary of a defensible undercarriage first article approval: permission tied to known evidence and known conditions, with future changes required to identify themselves.