How to inspect drones and audit a factory in China before payment

Define the product and inspection scope

Specify the destination market and the documents to review. Separate product checks, factory capability checks, and document verification in the purchasing brief. For an inspection assigned to our team, identify the tests, records, and acceptance criteria required before work begins.

Agree on a sampling plan

Use ISO 2859-1 as the reference for an agreed acceptance sampling plan. Record the lot size, inspection level, sampling scheme, AQL values, sample sizes, and acceptance and rejection numbers. Obtain these from the applicable standard tables before inspection.

General Inspection Level II can be specified for appearance, packaging, power-on checks, and basic functions. Consider a special inspection level for time-consuming or destructive tests, with the test scope and sample size agreed separately. Identify which units undergo flight, battery cycling, teardown, or packaging tests.

Define critical, major, and minor defects in the purchase specification. Battery leakage and failed safety functions warrant explicit rejection criteria; gimbal faults, video interruptions, missing accessories, and cosmetic scratches need clearly assigned classifications. If the buyer requires rejection upon finding any critical defect, write that decision rule into the contract.

Set inspection readiness as a contractual milestone: for example, all production completed and at least 80% packed. Record actual completion and packing status when inspection starts.

Inspect the aircraft, battery, and firmware

Build the checklist around the ordered configuration and reference sample. Record measurements against the agreed tolerances rather than relying on a general statement that the drone works.

• Structure and workmanship: Check shells for cracks and molding defects, folding arm locks for looseness, carbon fiber parts for delamination, and propellers for damage and correct markings. Check motor rotation, gimbal dampers, lens cleanliness, and mechanical movement. Where internal inspection is agreed, compare assembly and soldering with the specified workmanship criteria.
• Bench functions: Check startup indicators, app connection, sensor status, and calibration errors. Confirm the specified gimbal movements and obstacle sensor responses. Record faults by unit serial number.
• Flight functions: Agree on the flight procedure before testing. Check takeoff, landing, control response, and hovering drift in the specified positioning modes. Include low-battery and signal-loss return-to-home behavior in the test plan. Record results against the product specification.
• Control and video links: Measure stability, latency, and packet loss under documented test conditions. Compare the product's stated frequencies and radio configuration with its compliance documents. Record the conditions used for any distance measurement.
• Battery condition: Inspect for swelling, leakage, damaged insulation, oxidized terminals, and insecure retention. Measure cell voltage balance against the agreed battery specification. Include verification of the specified battery management protections and supporting test records.
• Firmware: Compare flight controller, motor controller, gimbal, remote controller, and smart battery versions with the approved configuration. Include the agreed regional settings and remote identification functions in the checklist.
• Traceability and labels: Cross-check electronic and physical serial numbers against the packaging and shipment list using the agreed identification scheme. Inspect battery and controller identification, regulatory markings, and label legibility. Specify any durability test before applying it.

Use an agreed teardown sample to compare component markings, circuit boards, and battery identification with the BOM. Photograph discrepancies and identify the affected units in the report.

Audit the factory and its records

Start with the supplier's legal identity. Compare its business license, Unified Social Credit Code, registered address, operating address, and business scope with records in the National Enterprise Credit Information Publicity System. Review abnormal-operation and serious-violation listings. Document which entity contracts with the buyer and which site performs production.

Walk through the production process. Establish whether circuit board assembly, reflow soldering, optical inspection, and protective coating are performed internally or through controlled subcontractors. Review the associated records. Inspect electrostatic protection, assembly fixtures, sensor and gimbal calibration equipment, motor balancing equipment, aging racks, and flight test facilities relevant to the ordered product.

Trace quality records through incoming, in-process, and final inspection. Review cell capacity and internal resistance records, motor checks, circuit board tests, first article approvals, work instructions, and torque tool calibration. Ask for final calibration and flight records linked to aircraft serial numbers, and compare their coverage with the agreed production requirements.

For ISO 9001 certification, search the certificate number or legal entity name through CNCA's public information platform and IAF CertSearch. Compare certificate status, the named entity, and the scope with the supplier's claimed activities. Review the stated accreditation information and resolve discrepancies with the issuer.

Assess engineering capability through relevant patent and software registration records and an agreed demonstration of design and firmware version management. Review environmental test equipment and records relevant to the specification. Check customs registration and credit information through GACC, and examine redacted export declarations for evidence of previous shipments.

Verify product compliance documents

For EU orders, request the manufacturer-signed EU Declaration of Conformity and supporting technical reports. Review the claimed application of RED 2014/53/EU and the relevant drone requirements under Regulation (EU) 2019/945. Match model identifiers and radio configurations to the ordered product. Where the conformity assessment involves a Notified Body, check its identification and relevant authorization in NANDO. Verify claimed laboratory accreditation and its testing scope through the relevant accreditation records.

For US radio compliance, search the supplied FCC ID in the FCC OET Equipment Authorization Search. Compare available internal photographs, labels, frequencies, and reports with the sample. Investigate mismatches between the authorized configuration and the production hardware. Review applicable Remote ID documentation separately under FAA 14 CFR Part 89, using the FAA UAS Declaration of Compliance public list to check the listed model.

For RoHS, review evidence addressing the ten restricted substances under Directive 2011/65/EU and amendment (EU) 2015/863. Check material and component coverage across the BOM. Review relevant IEC 62321 test reports and supplier documentation assembled under EN IEC 63000. Do not accept a report covering only the plastic enclosure as evidence for every component. Verify report identifiers through the issuing body's verification channel.

Check battery transport documentation

Request the UN38.3 Test Summary and supporting test report for the supplied battery design, referencing Section 38.3 of the UN Manual of Tests and Criteria. Compare battery model, nominal voltage, capacity, and watt-hours with the physical label. Verify the report identifier with the issuer and establish whether the documentation covers the assembled battery pack. Do not assume that a cell report establishes coverage for the finished pack.

Review the Safety Data Sheet (SDS) as a technical information document. Check its sixteen-section structure and consistency with the battery supplied, including hazard information and Section 14 transport information.

For lithium-ion batteries, UN 3480 identifies batteries shipped separately, while UN 3481 identifies batteries packed with or contained in equipment. Establish the actual packing configuration before checking the transport description. Compare product identifiers across the SDS, test documents, battery labels, and shipment records.

Have the proposed shipment's documentation and packing arrangement reviewed before booking. Include the applicable charge-state requirement in that review and record the shipment-specific instructions used for preparation.

Link payment to documented decisions

Agree on payment milestones in the purchase contract. Before the deposit, complete the supplier review, approve the reference samples, record the BOM, and review the required compliance evidence. Specify how component or firmware changes will be approved.

Use first article or production-stage inspection to compare the actual build with the approved configuration. Review component identity, flight performance, and calibration arrangements before authorizing further production.

Before the balance payment, require the agreed inspection report and completion of the transport document review. State how failed inspections, corrective work, and reinspection will be handled, including responsibility for associated costs. Set payment release against these documented conditions. Record unresolved defects or document mismatches for the buyer's decision before release.