Aircraft part warranty returns: out-of-box failure vs warranty claim, the RMA, freight and what to ask before you buy

Out-of-box failure vs warranty claim

Both are defects the seller answers for; they differ in timing, and that changes how fast the problem gets fixed. In a September 2025 best-practice paper published by the Aircraft Electronics Association (AEA), an MRO manager at ARTEX puts it this way:

• Out-of-box failure (OBF). A defect "evident immediately upon installation or within a very short period of use. Simply put, the part was unserviceable at delivery." Industry practice is expedited handling: OBFs are "typically prioritized for immediate replacement, often with minimal investigation."
• Warranty claim. A failure that develops in service during the warranty period, which "may be expressed in calendar months, flight hours, or cycles, and typically begins at either the date of shipment or installation." The part goes back for evaluation first, and the paper warns of "extended turnaround times before final resolution."

The same paper notes that "all out-of-box failures are, by definition, warranty events. However, not all warranty claims are out-of-box failures." It also describes a difference in the paperwork you get back from a manufacturer: a warranty repair is done under the repair station's procedures and comes back with a repair certificate, while an OBF part can be run back through the manufacturer's production system and, once it passes production testing, gets a new 8130.

Source for the first three rows: AEA, "Warranty Versus Out-of-Box Failure in Aviation" (2025). An OBF is only treated as one if you can show the part was bad on arrival; that is what the receiving record is for.

How long warranties run: examples from published terms

There is no standard period. IATA's Warranty Management Essentials (2024) says it plainly: "there is no standard for warranty agreements given that warranties may vary from OEM to OEM, from maintenance supplier to maintenance supplier and from airline to airline." The period depends on who sells the part, its condition, and what was negotiated. Some published examples, checked on 23 September 2026:

Note two patterns. The clock often starts at shipment or invoice, not installation, so a part on your shelf is using up its warranty. And condition matters: above, an inspected tag carries no warranty at all (see aircraft part condition codes).

What voids a warranty

Published exclusions look much alike from seller to seller:

• Handling and installation. McFarlane excludes defects from incorrect installation, improper usage or handling. RAM excludes "misuse, improper installation, improper operation, improper maintenance" and damage in an aircraft mishap.
• Opening the unit. RAM wants the part "as removed from the airplane" and excludes parts "disassembled, repaired, or altered outside of RAM." Penta lists tampered seals, contamination and third-party repairs.
• Costs around the part. RAM excludes "labor, transportation, exporting, and troubleshooting" and limits the remedy to repair or replacement of the part.

Two more catch buyers. A repaired unit's warranty covers the repair, not the whole unit: in a 2021 presentation on teardown reports hosted by the Aviation Suppliers Association (ASA), a unit that failed again within warranty was covered only if the second failure was the one the shop had fixed. And some sellers exclude AOG orders from returns: Penta's terms say special-order and AOG items "are not returnable under any circumstances".

The clock: notice windows and claim windows

Many disputes are lost on dates, not on the defect. Published terms usually set two deadlines: a short one for problems found on receipt, and a longer one for failures in service.

• On receipt. McFarlane asks for discrepancies and damage to be reported within five days of delivery and the original packaging kept. Penta's window is five calendar days from its shipping date, after which "all sales shall be deemed final." For a part in transit to another country, five days from shipment can end before the box is opened.
• After a failure. RAM requires the part to be back within 30 days of the defect date. IATA's table gives 90 days "in general" as the time to claim. AEA's older guide for avionics shops filing claims with manufacturers says to file "not to exceed 30 days from completion of work."

Where the contract is silent, US law has a loose default. Under Article 2 of the Uniform Commercial Code, a model law the states have adopted in their own versions, rejection must come "within a reasonable time" after delivery or tender, and the buyer must notify the seller (§ 2-602); goods the buyer fails to reject effectively, after a reasonable opportunity to inspect them, count as accepted (§ 2-606); and a buyer who has accepted goods must notify the seller of a breach within a reasonable time after discovering it "or be barred from any remedy" (§ 2-607). Written terms usually replace "reasonable" with a number. This is general information, not legal advice: which law applies and what your contract says decide the answer, so ask your counsel.

The RMA process, step by step

Almost every seller requires a return merchandise authorization (RMA) before anything ships back. McFarlane: "Returns without an RMA will not be accepted." A typical sequence, drawn from published processes:

1. Report in writing, inside the window. Your PO and invoice, what failed and when. IATA's minimum for a claim: part number, serial number, TSN and TSO, reason and date of removal, aircraft registration.
2. Fill in the seller's form. Hartzell asks for a Warranty Investigation Request first; its case number becomes the RMA. AEA's guide warns against a fault description that just says "INOP" and recommends photos of the findings.
3. Get the RMA and shipping instructions: where the part goes, how, and on whose account.
4. Ship as instructed. Hartzell asks for the RMA number on the outside of the box and the confirmation inside. Include the removal details and copies of the paperwork that came with the part.
5. Get the evaluation in writing. Fault confirmed means repair, replacement or credit; "no fault found" usually means charges (see below). Ask for the findings, not just the verdict.

Keep the part as removed until the seller answers; opening it is one of the exclusions above.

Who pays freight both ways, and what "no fault found" costs

Freight is where published terms differ most, so settle it before the PO:

"No fault found" (NFF) means the unit passed on the bench. IATA notes that every manufacturer has its own NFF policy and recommends photos and BITE screenshots with a claim, because "not all conditions can be replicated on a bench test." A precise fault description is the cheapest protection against an NFF invoice.

Also ask who pays customs on the return and on the replacement; see the Incoterms guide for how EXW, FCA and FOB split those costs on the original shipment.

Teardown reports and findings: what to ask for

The ASA-hosted presentation defines a teardown report (also called a workshop report, shop findings or work order) as "a summary of the work performed, parts replaced, the reason those parts were replaced," accompanying the 8130-3 or EASA Form 1. Its warranty lesson is specificity: when two shop visits both say only "repaired amplifier," owner and shop argue over whether the second failure is covered; when each report names the failed component, the answer is on paper. For a buyer:

• When you buy an overhauled or repaired unit, ask for the teardown report with the release certificate. It shows what the warranty is for.
• When a claim is evaluated, ask for the findings in writing, whichever way they go. A denied claim with a reason can be challenged; IATA's guidance is that declined claims "should not be always accepted by default" and that the warrantor should state the reason.
• Most shops give a summary, not every record they created, the presentation cautions. If you need more, ask.

What to document on receipt

Your receiving record is the evidence for an OBF. FAA Advisory Circular 20-154A (July 2024) describes a receiving inspection system; the parts of it that matter for a later claim:

• Box and packing. Visual check for "obvious physical damage, defects, and state of preservation," correct quantity, caps and plugs installed, and a shipping container suited to the item. Photograph the box and label before opening, then the part as found. Penta's terms, for one, send freight damage to the carrier.
• Numbers. Part, model and serial numbers match the packing slip, invoice, certificate, release tag and your PO.
• Paperwork. The certificate and trace are the ones you approved before ordering; the traceability guide covers what to check.
• Keep the packaging. For bulk shipments of identical parts, AC 20-154A recommends keeping original packaging with the parts for identification whenever possible; McFarlane's terms require it for verification of a return.
• Segregate doubtful parts. Parts with questionable documentation are kept apart from serviceable stock "until a sound determination can be made of their status."

Test or install soon: the notice window runs from delivery or shipment, not from when you opened the box. If what arrived looks not merely defective but unapproved or counterfeit, a return alone does not close the matter. The FAA's AC 21-29D (Change 1) says to segregate suspect parts, try to resolve the question with your supplier, and report them to the FAA, with FAA Form 8120-11, Suspected Unapproved Parts Report, as the standard means.

What to ask for on the quote, before you buy

IATA advises airlines to "indicate their expected minimum warranty terms on component orders" and negotiate. The same works for one line: ask for the warranty and return terms in writing on the quote, covering:

1. Warranty period by condition, in months, hours or cycles, and whether it starts at shipment, invoice or installation.
2. Notice window for discrepancies found on receipt, and from which date it counts.
3. Claim window and what the claim must contain.
4. Remedy: repair, replacement or credit, and who chooses. For an OBF, whether an expedited replacement is offered.
5. Freight both ways and customs on the return, for a confirmed defect and for NFF.
6. NFF, evaluation and restocking charges, as amounts.
7. Findings: a written evaluation or teardown report with the result.
8. Exclusions, especially seals, third-party repair and AOG or special-order lines.

Repeat the accepted terms on the purchase order. For the rest of the request, see the aircraft parts RFQ guide.

Sources

All checked on 23 September 2026.

• Warranty Versus Out-of-Box Failure in Aviation: Why the Distinction Matters — Lavett Reid, MRO manager, ARTEX; Aircraft Electronics Association repair station best-practice resources, September 2025.
• AEA Recommended Best Practices for Avionics Shops – Filing Warranty Claims — Aircraft Electronics Association, March 2010.
• Warranty Management Essentials, 1st Edition — IATA Maintenance Cost Technical Group, 2024 (sections 1, 4.1, 4.2 and 5).
• The Value of Those Teardown Reports — Roy Resto, presentation hosted by the Aviation Suppliers Association, 2021.
• AC 20-154A, Guide for Developing a Receiving Inspection System for Aircraft Parts and Materials — FAA, 3 July 2024 (paragraphs 7.6.6–7.6.12 and 7.12).
• AC 21-29D Change 1, Detecting and Reporting Suspected Unapproved Parts — FAA, 13 February 2018 (paragraph 5.3.8 and appendix A).
• Uniform Commercial Code § 2-602, § 2-606 and § 2-607 — Legal Information Institute, Cornell Law School.
• Warranties and Returns — McFarlane Aviation.
• Aircraft Parts Warranty — Hartzell Aviation.
• Parts Warranty — RAM Aircraft, L.P.
• Warranty — Penta Avionics.