Legal Risks and Liability in Trading Aircraft and Marine Spare Parts

JUDr. Jakub Dohnal, Ph.D., LL.M.
JUDr. Jakub Dohnal, Ph.D., LL.M.
29.4.2026 | ARROWS law firm

Trade in spare parts for aircraft and ships revolves around one fundamental thing: safety and legal liability. If you sell aviation or marine components, it is not just about ensuring they reach your customer on time and in good condition. Your business is interwoven with regulations, certifications, technical standards, contractual obligations, and financial penalties that can reach up to millions of Czech crowns. The attorneys at ARROWS, a Prague-based law firm, specialize in this area and understand it in depth, because they understand how real commercial risks manifest in this segment.

In the image, we see a lawyer advising on legal liability in the sale of spare parts.

Summary for decision-makers

Trading in aircraft and marine parts is not like selling ordinary goods. You face regulation on several levels at once: European standards, Czech regulations, international agreements, and special rules for certified components. The most serious risk is that you sell a part without the required documentation or of false origin, and the aircraft or vessel on which it was installed thereby loses its operational airworthiness/seaworthiness.

The fine imposed on you and on the vessel owner may reach up to CZK 5 million and more. A visit from an inspector from the Czech Civil Aviation Authority (ÚCL) or the maritime authority is then only the beginning.

The second part of the risk lies in contractual commitments: what exactly did you promise the buyer about the quality, origin, and fitness of the part? What warranty are you providing? What costs do you bear if the part turns out to be defective or counterfeit? The third area involves disputes with distributors, logistics partners, and customs authorities.

We will look at all of these challenges specifically and show you where money is most often lost and how to avoid the worst-case scenarios.

Regulatory framework and certification: What you need to know

When you sell an aircraft part, it must have a certificate of airworthiness issued by the European Union Aviation Safety Agency (EASA) or a national civil aviation authority, such as the Czech Civil Aviation Authority (ÚCL) in the Czech Republic. Most commonly, this is EASA Form 1, which confirms that the part has undergone inspection and technical checks and is suitable for installation on an aircraft. Without this document, the part is simply not legal to install. However, this is not merely a formality.

If you sell an aircraft part without valid documentation, liability is borne not only by the aircraft owner, but also by every person or organisation that installs the part. The fine for such a breach may reach up to CZK 5 million under Act No. 49/1997 Coll., on Civil Aviation, as amended.

At the same time, the aircraft automatically loses its airworthiness, meaning it cannot be legally operated. This triggers a cascading series of losses: you are left dealing with insurers, compensation for aircraft that consequently cannot be used, and potentially court disputes with those to whom you sold the part.

A similar approach applies in the maritime sector. Marine components must meet technical standards and safety requirements governed by European and international regulations. The chain of control and documentation is long, and you cannot afford any gaps. In both cases (aviation and maritime), these are areas where safety is not marketing. Safety is a legal reality, and non-compliance means fines that are far from negligible.

The attorneys at ARROWS, a Prague-based law firm, are familiar with these standards and understand their practical interpretation. If you are not sure whether your specific part is subject to certification requirements, or whether you have the correct type of documentation, it is sensible to have it verified by a lawyer before you sell the part on.

Distinguishing between original and certified parts

In practice, aircraft parts traders encounter parts described as “original” or “certified”, but the difference is not always clear. An original part is usually manufactured directly by the aircraft or engine manufacturer. A certified part is one that may come from another source (overhauled, repurposed), but has undergone the required inspection and certification procedure. Buyers often believe that “original” is automatically better and safer, and are therefore willing to pay a higher price. In reality, however, for aircraft operation the decisive factor from a legal perspective is whether it has certification, not its origin.

That does not mean origin does not matter. If you sell a part as “original” and the buyer later finds out it is not, this constitutes a breach of contract and misinformation about the quality of the goods. In such a case, the buyer has the right to demand a refund or a price reduction. This can be financially devastating for you, especially if you sold the part at a discount and the part is no longer available.

Most common questions on regulation and certification

1. What happens if you are not sure whether our supplier has the correct certificates?
You should always request an original copy of EASA Form 1 or an equivalent certificate, verify the information directly with EASA or the Czech Civil Aviation Authority (ÚCL), and if you have doubts, consult a lawyer. The attorneys at ARROWS, a Prague-based law firm, can verify your supplier and review the documentation before you start trading. This is not unnecessary paranoia; it is preventive protection.

2. What is the difference between a “used” part and an “overhauled” part?
A used part is a part that has already been in service, but has not been technically repaired or modified. An overhauled (refurbished) part is one that has undergone technical inspection, repair, and testing. For aircraft operation, the key difference is whether it has valid certification after the overhaul. Without it, it is not usable. If you sell a “repaired” part as “overhauled” without documentation, this again constitutes a breach of the duty to provide accurate information about the quality of the goods.

3. What if an inspection proves that we sold a counterfeit part?
This is followed by fines, legal disputes with the buyer, and possible criminal prosecution in the case of intentional fraud. ARROWS, a Prague-based law firm, can represent you in such situations and defend you against sanctions. However, it is better not to get into such a situation at all.

Contractual liability and warranties: What you promise and what it means

When you sell an aircraft or marine part, it is essential in the contract with the buyer that you clearly define what exactly you are selling, what quality the customer can expect, and what your rights and obligations are. A seemingly simple sentence such as “I am selling a certified aircraft part” may later lead to a dispute if the parties interpret the word “certified” differently.

Legal liability for defects in goods is primarily governed by the Czech Civil Code (Act No. 89/2012 Coll.), which also contains special provisions for relationships between businesses. As a general rule, the seller warrants that the goods sold have the characteristics agreed in the contract, or the characteristics customary for such goods.

If the part does not have these characteristics, the buyer is entitled to request repair, replacement, a price reduction, or even withdrawal from the contract. For entrepreneurs, the time limit for asserting rights arising from defective performance is primarily agreed in the contract; otherwise, the defect must be notified without undue delay after the buyer could have discovered it. For defects that already existed upon acceptance, a statutory objective time limit of two years from delivery of the item applies, unless the contract provides otherwise.

In practice, however, situations often arise where the seller includes in the contract a condition such as “the seller assumes no liability for the airworthiness of the part” or “the buyer will verify airworthiness themselves.” The Civil Aviation Authority warns that these very formulations frequently appear on online marketplaces (e.g., eBay) and are a signal that the part may not come from a verified source.

Such clauses may be invalid from a legal perspective or enforceable only in part. This is because they are generally interpreted rather against the party that used them, and courts may find such clauses invalid if they would unreasonably limit the buyer’s statutory rights, even in B2B relationships.

In any event, even if you attempt to exclude liability through a contractual clause, the factual responsibility for safety and fitness remains. If you sell a counterfeit or unfit part and it ends up on an aircraft that later has an accident, you face not only contractual liability, but also tort liability (damage caused to a third party) and potentially criminal liability.

Structure of a sales contract for aircraft and marine parts

A well-prepared sales contract should include the following key elements. First, it must precisely define the subject of the sale: the exact part number, serial number, manufacturer, and condition (new, overhauled, used). It must also include a certification statement: what certification the part has, which authority issued it, and its status (active, suspended, expired). This is followed by a list of the seller’s obligations: the seller guarantees that it has the right to sell the part, that the documentation is authentic, and that the part is fit for the stated use. The contract should also include terms for handling defective performance, i.e., what your rights and obligations are if the buyer claims the part is not fit for purpose. What is the return procedure? What are the costs of return shipping?

The most important part, however, is the definition of warranties and their limits. A quality warranty is usually provided for a certain period (for example, 12 months from the sale). During the warranty period, the seller undertakes that if a defect appears, it will repair it or replace the goods. After the warranty period ends, you are no longer primarily obliged to do anything if a defect is proven. But note: a warranty does not address legal defects. If you were to sell a part that belongs to someone else or is encumbered by a pledge, the rightful owner may reclaim the part, all your rights cease, while your obligation to compensate for damage remains.

The attorneys at ARROWS advokátní kancelář can prepare or review your sales contract so that your business is protected as much as possible, while the contract remains reasonable and compliant with the law. A poorly drafted contract may prevent you from defending yourself in the future, even if you are right.

Most common questions on contractual liability and warranties

1. Can we completely exclude our liability for defects in the contract?
No. Legal liability for defects arises from the law and cannot be fully excluded, at least not for consumers. In B2B relationships, the parties have more freedom, but even there courts tend to interpret exculpatory clauses (exclusion of liability) strictly. Moreover, if you knew or should have known that the part has a defect, excluding liability will not help you.

2. If we sell a part with a 12-month warranty and the defect appears only after 18 months, can we refuse to take it back?
Yes, if the defect was evidently the result of the passage of time or use and the part was in operation for 18 months. However, if it is proven that the defect already existed at the time of sale and was merely hidden, the buyer’s right usually remains. It is therefore important that the contract clearly states what is meant by a “defect” and what is meant by a “hidden defect.”

3. What if the buyer returns the part to us as defective, but we test it and find that it is fine?
Then it is up to you to use that evidence in court proceedings if the buyer requests a refund. You have the right to dispute it. However, an arbitral tribunal or a court will assess whether your test is relevant and whether damage could have occurred during transport. That is why it is important to have clear procedures: how the part is packed, how it is transported, and who bears contractual responsibility for it still functioning properly at the time of return.

Supply chains and the chain of liability: Who is responsible for what

Trade in aircraft and marine parts usually involves multiple entities in the chain. You buy from a manufacturer or distributor in China or elsewhere, and then you sell it on to designers, repair shops, or directly to airlines. If a problem arises at any of these stages, it is not always clear who is responsible for it.

A standard situation looks like this: You ordered a part from a Chinese manufacturer. The manufacturer sent you the part without the required certificate, and you did not notice it or did not have a contact for it. You then sold the part onward as “certified.” The buyer installed it on an aircraft and, during an inspection check, discovered that the documentation was missing. The inspection authority imposes an enforcement penalty, and the buyer turns to you to notify defects and request a refund and compensation for the losses incurred (e.g., the aircraft could not fly).

In such a case, you have at least two options. First, you can turn back to your Chinese supplier and call on them to provide the correct certification or refund your money. But this usually takes a long time and the Chinese supplier may not be willing. Second, you assume responsibility and resolve it with your buyer: either you refund the money or you arrange the correct certification.

If you want to minimize this risk, you should ensure in your contract with your suppliers that they will provide the required certificates and that they will assume liability if they fail to do so. This is usually done through an indemnification clause (a compensation clause), which says: “If we cause you any loss due to a third party, we will reimburse you.” But such clauses must be mutual and must be enforceable.

In international trade with a partner in China, however, the problem is that if a dispute results in legal proceedings, it will be arbitration or court proceedings in China or in a third country, not in the Czech Republic. This is complicated and expensive. The attorneys at ARROWS advokátní kancelář understand this issue and can work with international law and disputes with a foreign element. They will help you set up contracts so that enforceability of rights is as strong as possible.

Most common questions on supply chains and liability

1. How do we choose the right supplier to minimize risk?
Carry out due diligence, i.e., thorough verification. This means verifying the company’s registration, history, references, financial situation, and, where appropriate, requesting samples and certificates before you order a large quantity. The attorneys at ARROWS advokátní kancelář can help you prepare such a review and draft the questions you should ask the supplier.

2. What if someone in the supply chain turns out to be cheating?
There are complex legal liabilities involved, including the question of which of you (as the trader) bore responsibility or failed to detect the fraud. If you acted in good faith and have documentation showing that you requested certificates, a court may partially grant you the right to recover damages from your supplier. However, the sequence and logic of such disputes is often complex.

3. What insurance should we have in case something unexpected happens?
Product liability insurance for defective products or third-party liability insurance is essential. The insurer can then help cover compensation for damage. It is expensive, but without it you risk a single dispute financially ruining you.

Counterfeiting and fake parts: Detection and legal consequences

Among the most serious risks in the industry is that you might unknowingly purchase or sell counterfeit or fake parts. Counterfeiting in the aircraft parts sector is a serious problem highlighted by both national authorities (ÚCL – the Czech Civil Aviation Authority) and international agencies (EASA, FAA).

This is documented in detail by the case of AOG Technics, which for several years sold fake aircraft parts with forged certificates. Inspectors found that a number of aircraft were flying with parts that had fake EASA Form 1 documents.

This triggered a wave of inspection and investigative activity, and the affected companies and airlines found themselves in a legal and financial crisis. If you were the buyer and unknowingly purchased counterfeit parts from AOG Technics, you would be entitled to a refund and compensation for all losses. But if you were the seller and unknowingly resold counterfeit parts, you face liability for fraud and possibly even criminal prosecution.

How can you identify a fake part? Often it comes down to details: poor print quality on certificates, inconsistent numbers, strange packaging, unusual prices (too cheap). The Czech Civil Aviation Authority strongly warns against purchasing parts through unofficial channels, especially online. The only safe way is to buy from approved distributors and request original documentation, which you then verify directly with EASA or the relevant national authority.

The legal consequences of selling a fake part are serious. It is a breach of the obligation to disclose the correct quality of goods to the customer. It also endangers safety in aviation or maritime transport, which may constitute a criminal offence. In the worst case, your dispute is not resolved only in civil proceedings (refund), but also before a criminal court (a fine or imprisonment).

To prevent this, you should have very strict control procedures. Always verify certificates directly with EASA or ÚCL. Never buy from a supplier who cannot provide original documentation. If you suspect that a part has been counterfeited, report it immediately to the relevant authority.

Possible issues

How ARROWS can help (office@arws.cz)

Unknowingly purchasing a counterfeit component and reselling it to a buyer

ARROWS attorneys in Prague can represent you in negotiations with the buyer, arrange a refund, and, if necessary, defend you against claims for damages. They can also advise you on how to proceed in the event of criminal prosecution.

Purchasing parts from unverified or questionable sources (e.g., eBay)

Verification of the authenticity of the certificate and contact with EASA or ÚCL; ARROWS attorneys can assist you with these steps and with the documentation.

Inspection by the Czech Civil Aviation Authority and the risk of a fine

Preparing a defence, representation during the inspection, and negotiations with the authority to minimise the fine and demonstrate that you acted in good faith. ARROWS can also assist you with filing an appeal against the fine.

Dispute with a supplier over compensation for damage

Initiating arbitration or court proceedings in the Czech Republic or abroad; ARROWS attorneys specialise in disputes with an international element and can represent you.

Insurance and risk minimisation: What to insure and how

Insurance should be a necessity for you, not a luxury. There are several types of insurance that are relevant:

Product liability insurance for defective products is key. If you sell an aircraft or marine part that later proves to be defective, the injured party (for example, an airline whose aircraft were grounded as a result) may sue you for damages. Such losses can reach millions of Czech crowns. The policy provides this coverage and will ensure legal protection through the insurer in the event of a dispute.

Carrier’s liability insurance is relevant if you transport the goods yourself or if you arrange transport. During transport, a part may be damaged, lost, or something unexpected may happen. The policy will compensate the loss and generally protect your reputation.

Cargo insurance covers physical damage to the goods during transport. The distinction between cargo insurance and liability insurance is important: cargo insurance protects you against the loss of the goods themselves (if they are destroyed or lost), while liability insurance protects you against third-party claims that you caused them damage (you sold the goods and the damage manifested later).

Insurers and other entities offer specific products for air transport and logistics. Prices vary depending on the type of part, its value, and where the goods travel.

International trade: Contractual terms and jurisdiction

If you sell abroad, you must address which law applies to you, in which country any dispute will be resolved, and what the agreed delivery terms are (INCOTERMS).

INCOTERMS are international rules that determine who bears the costs of transport and insurance, and when the risk transfers from the seller to the buyer. There are 11 different INCOTERMS in total; the most common in the parts trade are FCA (the buyer arranges transport from your place of business), CIF (costs and insurance transfer to the buyer at the port of loading; used in sea transport), and DDP (you deliver all the way to the buyer’s premises; you bear all costs and risks).

If you choose the wrong INCOTERMS, it may mean that you bear the risk of destruction of the goods even after you have dispatched them. As a result, you may end up in a situation where the buyer claims the goods arrived damaged and you are required to pay compensation, even though you shipped them in proper condition.

It is equally critical in which country the dispute is resolved and under which legal system. If you sell to a European buyer, in many cases jurisdiction is determined by the buyer’s place of residence (if you are the seller). For you, this means that if a dispute arises, it will be handled, for example, in Germany or England, not in the Czech Republic. That is expensive and unfriendly. Therefore, when entering into a contract with a foreign buyer, you should agree that in the event of a dispute you will resolve the matter through arbitration (so-called arbitral proceedings) in a neutral country or under Czech law. Most commonly, international trade chooses arbitration in Paris, Hong Kong, or Singapore.

The attorneys of ARROWS, a Prague-based law firm, deal with these issues and can help you set the right terms in an international contract. This also includes disputes with an international element, where ARROWS has experience.

Potential issues

How ARROWS helps (office@arws.cz)

Unclear INCOTERMS and the risk that you will bear transport costs even after dispatch

Drafting and review of international contracts; ensuring that the INCOTERMS are clearly defined and aligned with your business strategy.

Dispute with a foreign buyer; Czech courts lack jurisdiction

Drafting an arbitration clause in the sales contract; representation in arbitration; ARROWS has experience with disputes involving a foreign element and with international law.

Uncertainty regarding legal classification and the law applicable to the contract

ARROWS attorneys will ensure that the contract clearly states which law governs it (e.g., Czech law or EU law), so that it is predictable.

Transactions with China or another country; a non-transparent supplier

Supplier due diligence; drafting terms to ensure enforceability of rights; advice on risks in the relevant jurisdiction.

Cross-border issues: customs duties, import fees, regulation

Advice on import and export terms; guidance on current tariffs and regulations; coordination with customs agents.

Final summary

Trading in aircraft and marine parts is promising and in demand, but it is not without risk. You are operating at the intersection of safety (aviation and maritime are critical sectors), certification (each part must have the correct documentation), international trade (suppliers are abroad, and so are buyers), and legal liability (if something goes wrong, you may face multi-million fines or legal disputes).

A proactive approach is essential. Verify your supplier before you start trading. Put contracts in place with a clear definition of rights and obligations. Make sure all certificates and documentation are authentic and up to date. Obtain insurance in case something goes wrong. And when an issue arises, do not hesitate to contact attorneys.

The attorneys at ARROWS, a Prague-based law firm, have experience with this exact area and understand it in depth. They will help you assess the risks of your specific situation, prepare contracts that protect you, and, if necessary, represent you in dealings with authorities or in legal disputes. If you want to trade safely and with minimal risk, this is the way forward.

Contact office@arws.cz and describe your situation. ARROWS attorneys will provide an initial consultation and help you set up the right processes for your business.

Frequently asked questions about legal services for traders in marine and aircraft parts

1. What happens if I unknowingly buy counterfeit parts from a supplier?
Focus on getting your money back and ensuring that these parts do not continue to circulate. Contact the supplier immediately and demand a refund. If you have already resold the parts, immediately notify the buyer and inform the Czech Civil Aviation Authority (Úřad pro civilní letectví) or the relevant maritime authority. Do not try to cover up the mistake; it could affect you much more severely. The attorneys at ARROWS, a Prague-based law firm, will help you with the legal procedure and communication with the authorities and the buyer. Contact office@arws.cz.

2. What is the minimum insurance coverage we should have?
It depends on the size of your company and how many parts you sell per year. As a rule, the coverage should be at least equal to the average value of your annual turnover, ideally more. If you sell parts worth CZK 10 million per year, you should have coverage of at least CZK 10–20 million. However, that is only the minimum. The insurer will propose additional coverage. ARROWS attorneys can help analyze your risk and select appropriate insurance. Write to office@arws.cz.

3. How should I behave if an inspector from the Czech Civil Aviation Authority visits me?
Be polite and cooperative, but do not provide any statements without an attorney. The inspection will focus on how your processes are set up in the area of standardization and certification of parts. If the inspector wants to see documentation, it is appropriate to provide it, but you should have an attorney who can advise you on whether it is suitable to disclose anything beyond that. Do not admit mistakes; let your attorney assess the situation. ARROWS, a Prague-based law firm, focuses precisely on legal representation in such situations. If you suspect an inspection is coming, contact office@arws.cz in advance and prepare.

4. What are the typical mistakes traders in this sector make?
The most common is insufficient supplier vetting and excessive trust that a certificate is always authentic. The second mistake is a poorly drafted sales contract that will not protect your interests in the event of a dispute. The third mistake is the absence of insurance. The fourth mistake is failing to keep up with changes in regulations; standards change, and if you do not account for this, you risk selling unusable parts. The attorneys at ARROWS, a Prague-based law firm, can help you avoid all of these mistakes. Have an audit of your processes prepared. Contact office@arws.cz.

5. What happens if a dispute ends up in court? How long does it take?
Civil litigation in the Czech Republic typically takes one to two years at first instance, followed by additional years on appeal. However, if the contract includes an arbitration clause, the dispute is resolved in arbitration, which may be faster (approx. 6–12 months) but tends to be more expensive. An arbitral award is final, but you then need to ensure its enforcement (i.e., collection of the money). It is worth doing everything possible to prevent a dispute from arising at all, which is achieved through good contracts and preventive measures. ARROWS attorneys can help you with this. Write to office@arws.cz.

6. Is there such a thing as a “safe” purchase of aircraft parts?
Not absolutely safe, but the risk can be minimized. Always buy from approved distributors or directly from the manufacturer. Always request the original EASA Form 1 or an equivalent certificate and verify it directly with EASA or the Czech Civil Aviation Authority (ÚCL).
Read supplier reviews and carry out due diligence. Have insurance. Put a solid legal basis (a contract) in place with a clear allocation of liability. If you do all of this, you reduce the risk to a minimum. ARROWS attorneys can help you with the methodology and processes. Contact office@arws.cz.

Disclaimer: The information contained in this article is of a general informational nature only and is intended for basic orientation in the matter based on the legal status as of 2026. Although we take the utmost care to ensure accuracy, legal regulations and their interpretation evolve over time. We are ARROWS, a Prague-based law firm, registered with the Czech Bar Association (our supervisory authority), and for maximum client security we maintain professional liability insurance with a limit of CZK 400,000,000. To verify the current wording of regulations and their application to your specific situation, it is necessary to contact ARROWS directly (office@arws.cz). We accept no liability for any damages arising from the independent use of the information in this article without prior individual legal consultation.

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