1. Introduction: When an Aircraft Crashes, Is the Airline the Only Defendant?

When a commercial aircraft crashes, public attention initially focuses on the airline.

Was the pilot properly trained? Was the aircraft maintained correctly? Did the airline ignore a technical warning? Was the crew fatigued? Did air traffic control make an error?

Yet another question can be considerably more important in complex aviation litigation:

What if the aircraft itself was defective?

Suppose an aircraft crashes not merely because of pilot error or inadequate maintenance, but because a flight-control system was defectively designed, a structural component failed prematurely, a sensor transmitted incorrect information, software reacted in an unsafe manner, or a critical component had been manufactured outside its approved specifications.

In such circumstances, liability may extend beyond the airline.

The aircraft manufacturer, engine manufacturer, component supplier, software developer or another participant in the aerospace supply chain may potentially face claims.

This means that after a serious accident involving an Airbus or Boeing aircraft, the legal question is not simply:

“Was the airline responsible?”

It may instead become:

“Was there a design defect, manufacturing defect or inadequate warning that contributed to the accident?”

The distinction is fundamental because airline liability and manufacturer liability generally arise from different legal regimes.

For international passenger transportation, the airline’s liability may be governed primarily by the 1999 Montreal Convention.

The manufacturer’s liability, however, will generally arise under the applicable national rules of product liability, tort law and negligence.

The same accident can therefore generate parallel claims against multiple defendants.

2. Airline Liability and Manufacturer Liability Are Not the Same

One of the most important principles in aviation accident litigation is that the airline and the aircraft manufacturer do not necessarily have the same legal responsibility.

Under Article 17 of the Montreal Convention, an air carrier is liable for damage sustained in the event of the death or bodily injury of a passenger where the accident causing that death or injury occurred on board the aircraft or during embarking or disembarking operations.

This is essentially a carrier liability regime.

Airbus or Boeing, however, is not normally the passenger’s contractual air carrier merely because it manufactured the aircraft.

Therefore, a claim alleging that a Boeing aircraft contained a defective flight-control system or that an Airbus aircraft contained a defectively manufactured structural component will generally have a different legal basis from the passenger’s claim against the airline.

A manufacturer claim may be based upon:

• strict product liability;
• defective design;
• manufacturing defect;
• failure to warn;
• negligence;
• breach of statutory safety obligations;
• negligent post-sale monitoring;
• component-part liability.

The precise cause of action depends heavily on the jurisdiction in which proceedings are brought and the law applicable to the dispute.

This produces one of the most important characteristics of international aviation litigation:

the airline can be liable without the manufacturer being liable, the manufacturer can be liable even where the airline also contributed to the accident, and in some cases several parties can be liable simultaneously.

3. Can Airbus or Boeing Actually Be Sued After a Crash?

Yes.

An aircraft manufacturer can potentially be sued where the claimant can establish the legal requirements of the applicable product-liability or tort regime.

However, the mere fact that an Airbus or Boeing aircraft crashed does not establish manufacturer liability.

Aircraft accidents can result from numerous causes, including:

• pilot error;
• inadequate training;
• deficient airline procedures;
• improper maintenance;
• weather;
• runway conditions;
• air traffic control;
• bird strikes;
• maintenance-provider negligence;
• defective aircraft design;
• defective manufacturing;
• defective components;
• software failures;
• combinations of several causes.

Accordingly, the essential question is not:

“Did a Boeing or Airbus aircraft crash?”

but:

“Did a defect attributable to the manufacturer cause or materially contribute to the accident and resulting damage?”

In modern aircraft litigation, this causation inquiry can become extraordinarily technical.

It may require analysis of millions of data points, flight-control logic, source code, structural metallurgy, aerodynamic modelling, maintenance history, certification documents and previous service incidents.

4. The Three Central Product-Liability Theories

Although legal terminology differs among jurisdictions, aviation product-liability disputes frequently revolve around three principal categories:

design defect, manufacturing defect and failure to warn.

Each addresses a different problem.

5. Design Defect: Was the Aircraft Dangerous Even Though It Was Built Exactly as Intended?

A design defect exists where the problem is not that one particular aircraft was manufactured incorrectly but that the underlying design itself was allegedly unsafe.

This distinction is critical.

Imagine that 500 aircraft are manufactured precisely according to the approved engineering drawings.

If a claimant argues that one aircraft departed from those drawings, the allegation concerns manufacturing.

But if the claimant argues that all 500 aircraft contain the same inherently unsafe design feature, the case concerns design defect.

Examples could theoretically involve:

• flight-control logic;
• sensor architecture;
• redundancy design;
• stall-protection systems;
• cockpit warning systems;
• structural fatigue characteristics;
• electrical-system architecture;
• emergency procedures;
• fuel-system design;
• automated control systems.

The legal test for design defect differs between jurisdictions.

In the United States, for example, product-liability law is principally governed by state law rather than by one uniform federal product-liability statute.

Depending on the applicable state law, courts may consider concepts such as:

• whether the design created an unreasonable risk;
• whether the product performed as an ordinary consumer would reasonably expect;
• whether the risks of the design outweighed its benefits;
• whether a feasible safer alternative design existed.

In aircraft cases, the final question can become particularly difficult.

A commercial airliner is not an ordinary consumer product.

Its design may involve millions of engineering compromises involving:

weight, performance, redundancy, fuel efficiency, aerodynamic stability, pilot workload, system complexity and safety.

Consequently, design-defect litigation frequently becomes a battle between highly specialised engineering experts.

6. Manufacturing Defect: When One Aircraft or Component Was Built Incorrectly

A manufacturing defect is conceptually different.

Here the design itself may be perfectly safe, but the individual aircraft or component was not manufactured according to the approved design or manufacturing specifications.

Consider a hypothetical example.

The engineering design requires a structural component to be manufactured using a particular alloy, treatment process and tolerance.

If the factory:

• uses an incorrect material;
• improperly installs a fastener;
• fails to perform required heat treatment;
• produces microscopic cracks;
• incorrectly assembles electrical wiring;
• omits a manufacturing process;

the resulting component may differ from the intended design.

That is the classic manufacturing-defect theory.

Real-world aviation regulation demonstrates why this distinction matters.

The FAA issues legally enforceable Airworthiness Directives (ADs) where it determines that an unsafe condition exists in an aircraft product and that the condition is likely to exist or develop in other products of the same type design.

For example, in 2026 the FAA issued an Airworthiness Directive concerning certain Airbus A350 nose-landing-gear components after reports that specified components had been manufactured without a required shot-peening process, potentially reducing their fatigue life. The directive required corrective action.

An Airworthiness Directive does not by itself establish civil liability in every later lawsuit.

However, such regulatory material can become highly important when lawyers and technical experts investigate whether a known unsafe condition, manufacturing deviation or corrective requirement is relevant to an accident.

7. Failure to Warn: What If the Manufacturer Knew About the Risk?

An aircraft can also potentially give rise to liability even where its physical design or manufacture is not itself characterised as defective.

The issue may instead concern warnings and instructions.

Manufacturers continuously receive operational data after aircraft enter service.

They may become aware of:

• recurring component failures;
• unusual sensor behaviour;
• software anomalies;
• structural cracking;
• misleading cockpit indications;
• operational limitations;
• maintenance vulnerabilities.

This raises another product-liability question:

Did the manufacturer adequately warn operators, pilots and maintenance organisations about a known or reasonably discoverable risk?

A failure-to-warn case may focus on documents such as:

• Aircraft Flight Manuals;
• maintenance manuals;
• Flight Crew Operating Manuals;
• service bulletins;
• operator communications;
• technical notices;
• emergency procedures;
• training material.

The FAA expressly states that type-certificate holders have continuing responsibilities that include notifying the authority when they become aware of certain failures, malfunctions or defects, developing design changes needed to correct unsafe conditions and incorporating corrective action into future production.

EASA similarly operates a continuing-airworthiness regime under which mandatory action can be required where evidence indicates that an aircraft’s safety level may otherwise be compromised.

Therefore, manufacturer responsibility does not necessarily end on the day the aircraft leaves the factory.

Modern aviation law recognises a continuing relationship between aircraft design, operational experience and continued airworthiness.

8. Does Regulatory Certification Protect the Manufacturer from Liability?

Commercial aircraft undergo extraordinarily sophisticated certification processes.

A Boeing aircraft operating commercially may have received FAA type certification, while an Airbus type may principally be certificated through EASA and subsequently validated by other aviation authorities.

It may therefore appear logical to argue:

“The aviation authority approved the aircraft. How can the manufacturer still be sued?”

Certification is obviously important evidence.

But regulatory approval and civil product liability are conceptually different questions.

Certification generally establishes that the aircraft satisfied the applicable regulatory framework for approval.

Product-liability litigation may nevertheless ask whether, under the applicable substantive law:

• the product was defective;
• information supplied to regulators was adequate;
• later operational information revealed new risks;
• warnings were sufficient;
• corrective action was taken appropriately;
• the defect caused the accident.

Regulators themselves recognise that unsafe conditions may emerge after certification.

That is precisely why systems such as FAA and EASA Airworthiness Directives exist.

The FAA describes ADs as legally enforceable rules intended to correct unsafe conditions in aircraft, engines, propellers and appliances.

Accordingly:

type certification is highly significant, but it should not automatically be confused with absolute immunity from subsequent civil liability.

9. Component Manufacturers May Also Become Defendants

A modern Airbus or Boeing is not manufactured entirely by one company.

Commercial aircraft involve extraordinarily complex international supply chains.

The aircraft may incorporate:

• engines;
• avionics;
• flight-control computers;
• sensors;
• landing gear;
• brakes;
• seats;
• wiring;
• software;
• hydraulic systems;
• navigation equipment;

manufactured by numerous suppliers.

Suppose the accident was caused by a defective engine component.

The relevant defendant may not necessarily be the airframe manufacturer alone.

Potential defendants may include:

• the aircraft manufacturer;
• engine manufacturer;
• component manufacturer;
• software supplier;
• maintenance organisation;
• airline.

The new EU Product Liability Directive expressly reflects this supply-chain approach by recognising potential liability of both manufacturers of defective products and manufacturers of defective components integrated into a product.

This is particularly significant in aviation because an “aircraft defect” may ultimately be traced to one comparatively small component within a highly complex system.

10. How Do Lawyers Prove That the Aircraft Was Defective?

This is usually the most difficult part of the case.

Aviation product-liability cases depend heavily on technical evidence.

Important evidence may include:

• Flight Data Recorder data;
• Cockpit Voice Recorder material;
• wreckage examination;
• engine teardown reports;
• maintenance records;
• aircraft technical logs;
• digital maintenance data;
• manufacturer engineering documents;
• certification records;
• service bulletins;
• Airworthiness Directives;
• previous incident reports;
• simulator testing;
• metallurgical analysis;
• software analysis;
• emails and internal technical communications.

A single flight-data recorder may contain information relating to hundreds or thousands of parameters.

Investigators may reconstruct the final seconds of a flight almost moment by moment.

But civil litigants must still demonstrate causation.

Finding a defect is not always sufficient.

The claimant generally has to connect the alleged defect with the accident and ultimately with the death, injury or other compensable damage.

11. Accident Investigation and Civil Litigation Are Different Processes

Another important distinction is frequently misunderstood.

An official aircraft accident investigation is primarily a safety investigation.

Civil litigation is a process for determining legal liability and compensation.

Those objectives are different.

This distinction becomes particularly clear in the United States.

Under 49 U.S.C. §1154(b), no part of an NTSB report relating to an accident or accident investigation may be admitted into evidence or used in a civil damages action arising from matters mentioned in the report. Separate restrictions also apply to discovery and use of cockpit recordings and transcripts.

This does not mean that all factual material connected with the investigation disappears from subsequent litigation.

But lawyers must carefully distinguish between:

• official safety conclusions;
• factual investigative material;
• independently obtained evidence;
• expert testimony.

Therefore, the statement:

“The accident report says the aircraft had a design problem, so the manufacturer automatically loses the civil case”

would be legally incorrect.

An accident investigation may provide extraordinarily important technical information, but civil liability must still be established through the applicable judicial process.

12. What Happens When Both the Airline and Manufacturer Contributed to the Accident?

Aircraft accidents rarely fit perfectly into a single category.

Consider a hypothetical accident involving four elements:

1. A sensor was defectively designed.
2. The manufacturer’s warning concerning that sensor was inadequate.
3. The airline had failed to perform a recommended maintenance action.
4. The pilots responded incorrectly when the malfunction occurred.

Who is liable?

Potentially, several parties.

The dispute may involve:

Airline → operational negligence

Manufacturer → defective design/failure to warn

Maintenance organisation → negligent maintenance

Pilots → operational error attributable to the carrier

The court may then have to determine:

• causation;
• comparative fault;
• contribution;
• indemnification;
• rights of recourse.

This is why aircraft accident litigation frequently consists of multiple proceedings and cross-claims between defendants.

A passenger’s claim against the airline and a product-liability claim against the manufacturer should not necessarily be viewed as mutually exclusive.

13. The European Product Liability Regime

Product liability is also undergoing major reform within the European Union.

Directive (EU) 2024/2853 replaces the historic Product Liability Directive 85/374/EEC and modernises the European product-liability system.

The new Directive provides that a product is defective where it does not provide the safety that a person is entitled to expect or that is required under EU or national law.

Relevant circumstances include the product’s:

• design;
• technical features;
• presentation;
• instructions;
• foreseeable use;
• safety requirements.

The Directive also addresses one of the greatest practical problems in highly technical product cases: proof.

Although the claimant remains generally responsible for proving defect, damage and causation, the Directive introduces presumptions in certain circumstances, including where the claimant faces excessive difficulty in proving defect or causation because of technical or scientific complexity.

That concept is particularly interesting in aviation litigation.

Few injured passengers can independently explain:

• flight-control source code;
• aerodynamic stability;
• metallurgical fatigue;
• redundant sensor architecture;
• software integration.

Modern product-liability regimes increasingly recognise this information asymmetry.

There is, however, an important transitional point.

As of August 2026, the new Directive has not yet become the applicable regime for products already placed on the market. It applies to products placed on the market or put into service after 9 December 2026. Directive 85/374/EEC continues to govern products placed on the market or put into service before that date.

This date can therefore become highly important in future European product-liability litigation.

14. Product Liability under Turkish Law

A manufacturer claim can also arise before Turkish courts where the necessary jurisdictional and choice-of-law requirements are satisfied.

Türkiye has a specific statutory product-liability framework under Law No. 7223 on Product Safety and Technical Regulations.

Article 6 provides that where a product causes damage to a person or property, its manufacturer or importer is required to compensate the damage.

The injured party must establish the damage and the causal connection between the relevant non-compliance and the damage.

Where more than one manufacturer or importer is responsible for the damage, they may be jointly liable.

The statute also provides that contractual provisions excluding or reducing the manufacturer’s statutory product-liability responsibility are ineffective.

Law No. 7223 broadly applies to products placed or intended to be placed on the market or put into service. Where a product is governed by special legislation, the statute applies to matters not regulated by the special regime.

Depending on the circumstances, general Turkish tort principles under the Turkish Code of Obligations may also become relevant.

Consequently, where an aircraft accident has a sufficient connection with Türkiye, lawyers must not analyse the case exclusively under the Turkish Civil Aviation Act or Montreal Convention.

Potential manufacturer liability must be investigated separately.

15. International Product Liability: Which Country’s Law Applies?

Aviation accidents are inherently international.

Consider an example:

• the airline is Turkish;
• the aircraft is manufactured in France;
• an engine is manufactured in the United States;
• the aircraft is registered in Türkiye;
• the accident occurs in Italy;
• passengers come from fifteen countries.

Which country’s product-liability law applies to the manufacturer?

That question may determine the entire case.

Under Turkish private international law, Article 36 of Law No. 5718 on Private International Law and International Civil Procedure specifically regulates non-contractual manufacturer liability.

It provides, in simplified terms, that liability for damage caused by manufactured products may, at the injured person’s choice, be governed by:

• the law of the manufacturer’s habitual residence or place of business; or
• the law of the country where the manufactured product was acquired,

subject to the statutory condition concerning whether the product entered that market with the responsible person’s consent.

This specialised choice-of-law rule can become extremely important in cross-border aircraft and component liability disputes.

16. Can Families Simply Sue Boeing in the United States?

Not necessarily.

The fact that Boeing is a US aircraft manufacturer does not mean that every accident involving a Boeing aircraft anywhere in the world will necessarily be litigated to judgment in the United States.

The court must consider issues including:

• personal jurisdiction;
• subject-matter jurisdiction;
• venue;
• applicable law;
• forum non conveniens.

One of the most famous aviation cases illustrating this issue is Piper Aircraft Co. v. Reyno, decided by the US Supreme Court in 1981.

The case arose from an aircraft crash in Scotland in which all passengers were killed. Product-liability claims were pursued against the American aircraft manufacturer, but the US Supreme Court upheld the application of the doctrine of forum non conveniens, explaining that the fact that the law of the alternative forum was less favourable to the plaintiffs did not by itself prevent dismissal.

The principle remains highly relevant to international aviation litigation.

A claimant may prefer the United States because of:

• discovery procedures;
• jury trials;
• product-liability doctrine;
• potentially higher damage awards.

Manufacturers may respond that another country is the more appropriate forum because:

• the crash occurred there;
• witnesses are there;
• the airline is located there;
• maintenance evidence is located there;
• accident investigators are there.

Therefore:

“Can Boeing be sued in America?” and “Will the American court keep the case?” are two different questions.

Similar jurisdictional complexity can arise when proceedings are contemplated against Airbus entities in Europe or elsewhere.

17. What Damages Can Be Claimed Against a Manufacturer?

Available damages depend on the governing law.

Potential categories may include:

• death-related compensation;
• personal injury damages;
• medical expenses;
• loss of earnings;
• loss of financial support;
• funeral expenses;
• pain and suffering;
• psychological injury;
• property damage;
• other pecuniary and non-pecuniary losses.

In some US jurisdictions, punitive damages may potentially become an issue where the applicable legal threshold is satisfied.

However, punitive damages are not universally recognised.

They may be unavailable or severely restricted in many jurisdictions, including under legal traditions fundamentally different from US tort law.

Therefore, choice of forum and applicable law can influence not only whether the manufacturer is liable, but also how much compensation may legally be awarded.

18. Can the Airline Sue Airbus or Boeing?

Yes, potentially.

Manufacturer litigation does not only concern passengers and their families.

The airline itself may suffer extraordinary losses from a defective aircraft.

These may include:

• destruction of the aircraft;
• grounding losses;
• replacement aircraft costs;
• passenger compensation;
• lost revenue;
• reputational damage;
• maintenance costs;
• fleet modification costs.

The airline may therefore seek contractual indemnification or damages against the aircraft manufacturer or component supplier.

However, commercial aircraft purchase agreements contain highly sophisticated provisions concerning:

• warranties;
• exclusive remedies;
• limitation of liability;
• consequential damages;
• indemnities;
• insurance;
• applicable law;
• arbitration or jurisdiction.

Therefore, an airline’s commercial claim against an aircraft manufacturer can look very different from a passenger’s personal-injury product-liability claim.

19. What If the Aircraft Was Leased?

The problem becomes even more complicated when the aircraft is leased.

A commercial aircraft may involve:

Manufacturer → Aircraft Owner / Lessor → Airline / Lessee → Passenger

If a defect causes an accident:

the passenger may pursue the airline;

the passenger may potentially pursue the manufacturer;

the aircraft owner may pursue claims relating to destruction of the aircraft;

the airline may seek indemnity from the manufacturer;

the lessor may rely on contractual warranties or assignments;

insurers may exercise subrogation rights.

A single aircraft accident can therefore generate a network of litigation between:

• passengers;
• airline;
• manufacturer;
• lessor;
• banks;
• insurers;
• maintenance organisations;
• component suppliers.

This is one reason aviation accidents routinely become some of the most legally complex international disputes.

20. The Role of Previous Incidents and Airworthiness Directives

One of the most important questions after an accident is:

Was this risk already known?

Lawyers may investigate whether similar incidents had previously occurred involving:

• the same aircraft type;
• the same component;
• the same software;
• the same sensor;
• the same structural area.

They may also investigate:

• Service Bulletins;
• Airworthiness Directives;
• regulatory correspondence;
• previous operator reports;
• manufacturer communications.

The FAA issues an AD where it finds both that an unsafe condition exists and that it is likely to exist or develop in other products of the same type design.

Evidence that a particular risk had already generated regulatory or technical attention may therefore become highly important when determining:

• foreseeability;
• knowledge;
• warning obligations;
• adequacy of corrective measures.

Again, such material does not automatically prove liability.

But it may fundamentally change the evidentiary landscape.

21. A Hypothetical Airbus or Boeing Accident

Consider a hypothetical flight from Istanbul to London.

Shortly after departure, one of the aircraft’s sensors provides erroneous information.

The flight-control system reacts to that information.

The pilots attempt to correct the situation but receive confusing cockpit indications.

The aircraft crashes.

The subsequent investigation identifies several possible factors:

• a sensor contained a manufacturing defect;
• the system relied too heavily on that sensor;
• the manufacturer had previously received reports of similar malfunctions;
• the airline had not incorporated an optional software update;
• pilot training did not adequately address the malfunction.

Who caused the crash?

The answer may not be:

one party.

The manufacturer may face a design-defect claim.

The sensor supplier may face a manufacturing-defect claim.

The airline may face claims involving training and operational procedures.

The maintenance provider may face allegations regarding inspection.

This is exactly why serious aviation litigation often involves multiple causation rather than a search for one single responsible actor.

22. The Manufacturer’s Main Defences

Aircraft manufacturers also have substantial defences.

A manufacturer may argue that:

• no defect existed;
• the aircraft complied with applicable design standards;
• the alleged defect did not cause the accident;
• the airline failed to maintain the aircraft;
• required Airworthiness Directives were not complied with;
• the aircraft was improperly modified;
• pilots departed from established procedures;
• a component supplied by another manufacturer caused the failure;
• the claim is time-barred;
• the chosen court lacks jurisdiction;
• another country is the appropriate forum.

In some jurisdictions, a manufacturer may also invoke a development risk defence, arguing essentially that the relevant defect could not have been discovered given the state of scientific and technical knowledge at the relevant time.

The new EU Product Liability Directive expressly retains a version of this defence, subject to the Directive’s rules and national implementation choices.

Aircraft product-liability cases are therefore rarely straightforward.

23. The Central Legal Question: Who Controlled the Risk?

Aircraft accident litigation can ultimately be understood through one central question:

Who was legally responsible for controlling the risk that materialised?

If the risk arose from:

pilot operation → the airline may be responsible.

If it arose from:

maintenance → the airline or MRO provider may be responsible.

If it arose from:

aircraft design → the manufacturer may be responsible.

If it arose from:

manufacturing → the manufacturer or component supplier may be responsible.

If the risk arose from several factors simultaneously → several parties may share liability.

This is what separates sophisticated aviation litigation from a simple compensation claim.

24. Conclusion: An Aircraft Crash Is Not Automatically an Airline-Only Case

When an Airbus or Boeing aircraft crashes, legal analysis should never end with the airline.

The aircraft itself must also be investigated.

The critical questions include:

Was the aircraft correctly designed?

Was it manufactured according to specifications?

Did a component fail?

Did software behave as intended?

Were adequate warnings issued?

Did the manufacturer know of similar previous incidents?

Were required corrective measures taken?

Did the alleged defect actually cause or contribute to the accident?

International passenger claims against airlines may primarily fall within the Montreal Convention carrier-liability framework.

Manufacturer claims, by contrast, may arise under domestic and international principles of product liability, negligence and tort law.

In Türkiye, Law No. 7223, the Turkish Code of Obligations and the private international law rules contained in Law No. 5718 may become relevant.

In the European Union, product liability is entering a new era under Directive (EU) 2024/2853, particularly because the new regime addresses complex technology, component manufacturers and evidentiary difficulties faced by injured persons. The new Directive will apply to products placed on the market or put into service after 9 December 2026, while the previous regime continues to apply to earlier products.

In the United States, state product-liability laws, federal aviation regulation, jurisdiction rules and doctrines such as forum non conveniens can all influence whether a case against an aircraft manufacturer proceeds.

The practical result is important:

Yes, Airbus, Boeing or another aerospace manufacturer can potentially be sued after an aircraft accident.

But manufacturer liability does not arise merely because its aircraft was involved in the crash.

Successful product-liability litigation requires proof connecting:

Defect → Causation → Accident → Damage.

And in commercial aviation, proving that chain may require reconstructing not only the final seconds of the flight, but years of aircraft design, certification, manufacturing, maintenance and operational history.

That is why aircraft manufacturer liability lies at one of the most technically demanding intersections of aviation law, product liability, international private law, engineering evidence and mass-tort litigation.