Aug 22, 2026
by Wu Yunzhe
15 MIN READ
In 2020, after years of negotiations, the EU–China Bilateral Aviation Safety Agreement (BASA) and its Technical Implementation Procedures (TIP) opened what was described as a “new era” of civil aviation cooperation between the two sides.
Earlier this year, EASA stated that China and Europe had disagreements over the interpretation and implementation of certain provisions of the BASA and TIP. As those disagreements continue, the continued mutual confidence underpinning the BASA and TIP framework is also coming under pressure. The bilateral mechanism is now facing one of its most important real-world tests since it was established.
Starting from the institutional logic of the BASA and TIP, this article examines why first validation results in a high level of EASA involvement in the type certificate validation of China’s large transport aircraft. It then considers a more practical question: in such an environment, is engineering capability alone sufficient to drive issue closure, and why does technical negotiation capability become an important factor affecting the efficiency of the validation process?
In March this year, Steven Higgins, International Certification Policy Manager at the European Union Aviation Safety Agency (EASA), stated during a presentation at the 2026 EASA Certification Conference that EASA and the Civil Aviation Administration of China (CAAC) have disagreements over the interpretation and implementation of the EU-China Bilateral Aviation Safety Agreement (BASA) and its Technical Implementation Procedures (TIP). He also indicated that these disagreements were already affecting industry and aircraft deliveries.
Following Higgins’ remarks in March, Airbus held its first-quarter 2026 results briefing on 28 April. Airbus CEO Guillaume Faury and CFO Thomas Toepfer both mentioned that nearly 20 aircraft originally scheduled for delivery to China in the first quarter had encountered an “administrative delay”. At the same time, they said the issue had been resolved and that the affected aircraft would be delivered during the second quarter of 2026.
In May, Bloomberg was the first to link this situation to the ongoing EASA validation of the C919 type certificate, suggesting that China was using Airbus deliveries to put pressure on Europe in response to the slow progress of the C919 type certificate validation. Reuters subsequently noted that it could not independently verify the Bloomberg report. In early June, however, Reuters reported that Airbus deliveries rose significantly in May, partly because aircraft previously affected by the regulatory stand-off with China had been released. This broadly supported what Airbus had said in April.
So far, there is no evidence establishing a direct causal link between the EASA validation of the C919 type certificate and Airbus aircraft deliveries to Chinese customers. But when the two developments occur at the same time, it is easy for different parties, including mainstream media, to place them within a broader narrative of China and Europe “blocking” each other, or even within the wider context of trade tensions.
The broader geopolitical context helps explain why such an interpretation has gained traction. It does not, however, establish a causal link. But the issue can also be examined from the perspective of the applicable regulatory framework. In fact, both matters operate within the same framework for bilateral airworthiness cooperation between the European Union and China.
That framework consists of the EU-China Bilateral Aviation Safety Agreement, referred to below as the BASA or the Agreement, signed by the European Union and the Government of the People’s Republic of China in 2019, and the Technical Implementation Procedures, or TIP, adopted by EASA and CAAC in 2020.
The BASA was signed on 20 May 2019. After completion of their respective legislative and administrative procedures, the Agreement entered into force on 1 September 2020. Just two days later, on 3 September, EASA and CAAC signed the TIP under Annex I to the BASA.
At the time, both sides regarded the BASA and TIP as an important milestone in EU-China civil aviation cooperation. CAAC described the Agreement as “an important milestone in bilateral cooperation in the field of civil aviation”, while EASA said the two sides had thereby “start a new era of cooperation”.
Against this background, after years of negotiations finally resulted in the BASA and TIP, what are the key factors now affecting their implementation? How should the current disagreements be resolved? What do they mean for the C919 type certificate validation project? And what can the relevant parties do to mitigate their impact as far as possible? The following sections address these questions.
It is difficult for outsiders to know the specific substance of the disagreements between the two sides in implementing the BASA and TIP. To understand their significance within the bilateral framework, however, it is first necessary to understand one of its foundations: mutual confidence.
The BASA and TIP are founded on mutual confidence, and that confidence is fundamental to the reciprocal acceptance of findings of compliance and certificates under the bilateral framework.
The Agreement expressly recognizes that reciprocal acceptance of findings of compliance and certificates requires continued confidence in the reliability of the other Party’s compliance-finding processes.
There are two important points here. First, mutual confidence is an institutional prerequisite for the reciprocal acceptance of findings of compliance and certificates under the BASA. Second, that confidence must be maintained throughout implementation of the Agreement.
The BASA establishes the concept of qualification of the Competent Authorities. It makes clear that meeting the prescribed qualification requirements provides the institutional basis for the other Party to accept a Competent Authority’s findings of compliance and certificates.
The BASA further links the qualification of the Competent Authorities to mutual confidence. It requires the Technical Agents to regularly assess whether the other Party’s Competent Authorities continue to meet the qualification requirements in order to maintain mutual confidence in each other’s systems.
Taken together, these provisions establish the following relationship:
Qualification of the Competent Authorities
↓
Mutual confidence
↓
Reciprocal acceptance of findings of compliance and certificates
Annex I of the BASA further distinguishes between initial qualification and continued qualification, with the same qualification requirements applying to both.
For initial qualification, the BASA states that, following a confidence-building process and initial mutual assessments conducted before the Agreement was signed, CAAC and EASA were considered at the time of signature to meet the applicable qualification requirements for Competent Authorities.
The qualification requirements under the BASA cover a wide range of areas, including legal and regulatory structures, organizational resources, personnel competence, processes and oversight systems.
Building this initial mutual confidence across so many areas was clearly not easy. The European Union and China began BASA negotiations in August 2013, but the Agreement was not ultimately signed until May 2019. The length of that process itself illustrates the difficulty involved.
But qualification is not established once and then deemed permanent. The BASA also provides for continued qualification. To maintain mutual confidence in each other’s systems, the Technical Agents must regularly assess whether the other Party’s Competent Authorities continue to meet the qualification requirements. The TIP specifies the modalities of these assessments and the information on which they may be based.
Therefore, when Higgins said in March that EASA believed there had been clear instances of divergence with the TIP in practice, and that information would be collected, documented and submitted to the Certification Oversight Board (COB), this at least indicates that the implementation disagreements had reached a stage at which further handling through the bilateral institutional mechanism was considered necessary.
The existence of disagreements does not in itself mean that either side has concluded that the other no longer meets the qualification requirements for a Competent Authority. Nor does it mean that the two sides have lost mutual confidence, or that the mechanism for accepting findings of compliance and certificates has been suspended. Depending on their substance, persistent disagreements could nevertheless become relevant to the maintenance of mutual confidence, particularly if they were to reveal a more fundamental misunderstanding of the principles of the BASA.
So what mechanisms do the BASA and TIP provide for resolving such disagreements?
The BASA and TIP establish a clear mechanism for resolving disagreements arising under the bilateral framework.
The first body to consider is the Certification Oversight Board, or COB, mentioned by Higgins.
Annex I of the BASA establishes the COB as a technical coordination body under the joint leadership of the Technical Agents and accountable to the Joint Committee. Its functions include resolving technical issues affecting implementation of Annex I, developing, approving and revising the TIP, and defining procedures to ensure continued confidence in each other’s compliance-finding processes.
It is useful to place the COB within the broader BASA and TIP framework.
As a general principle for resolving disagreements, the BASA states that the Parties should make every effort to resolve any disagreement concerning cooperation under the Agreement through consultation at the lowest possible technical level. The TIP further specifies that issues that cannot be resolved at the operational level should be promptly escalated through the respective management levels of the Technical Agents. Issues that cannot be resolved between the Technical Agents may then be raised to the COB, and issues that cannot be resolved by the COB are referred to the Joint Committee.
The escalation path under the BASA and TIP is therefore:
Joint Committee
↑
COB
↑
Escalation through the management levels of the Technical Agents
↑
Operational level
Against this background, Higgins’ reference to collecting information on disagreements over TIP implementation and submitting it to the COB can be understood as indicating that EASA considers these implementation disagreements appropriate for consideration through the COB, where the two sides can clarify which practices are consistent with the existing BASA and TIP arrangements and which may need to be adjusted.
The fact that the matter is being brought to the COB indicates that it has reached the stage provided for in the BASA and TIP escalation process. Persistent disagreements of this kind can place additional pressure on continued mutual confidence between the two sides. It is important, however, to distinguish pressure on mutual confidence from a conclusion that either side no longer meets the applicable qualification requirements. Nor can such pressure, by itself, be taken as evidence that EASA has changed its specific approach to the C919 validation project.
Against this broader bilateral background, what can be said with greater certainty about the C919 type certificate validation itself?
The conclusion is straightforward. The C919 type certificate validation is inherently a higher-involvement validation project because it is EASA’s first validation of a CAAC type certificate in this product category.
To understand why the C919 inherently requires a high level of involvement by the Validating Authority, it is first necessary to understand how the BASA and TIP structure the validation of type certificates.
For different types of design certificates and approvals, the BASA and TIP provide for two broad routes: automatic acceptance and validation. Validation is further divided into Administrative Validation, Streamlined Validation and Technical Validation, with progressively increasing levels of validation activity.
A type certificate issued by CAAC is subject to Technical Validation by EASA.
The core of Technical Validation is that EASA, acting as the Validating Authority, issues its own certificate through a validation process involving a defined level of involvement.
Annex I of the BASA expressly provides that, during the first validation of a given product category, the Validating Authority will exercise special procedures and scrutiny, particularly with regard to the Certificating Authority’s processes and methods, as further detailed in the TIP. The TIP explains that the objective is to verify, through a real certification exercise, how the Certificating Authority implements its own procedures in practice and makes findings of compliance against the certification basis. In such a case, the Validating Authority exercises a higher level of involvement than would otherwise apply.
For EASA, therefore, the C919 validation is both a product validation project and a review of how CAAC, as the Certificating Authority, applies its processes and methods in the certification of a large transport aircraft.
The special scrutiny applicable to the C919 therefore follows from its status as a first validation in this product category. It applies irrespective of the current disagreements over BASA and TIP implementation.
What can be established independently of that question is that, as a first validation in this product category, the C919 is already subject to special procedures and scrutiny under the BASA.
The special procedures and scrutiny associated with a first validation can have very practical consequences for the way individual issues are reviewed and closed:
For the applicant and the Certificating Authority, this additional scrutiny means that preparing the necessary evidence and closing individual issues may require more time and more intensive communication and coordination.
There is another possible effect. Issues arising in the C919 validation project may, in turn, provide input to EASA’s assessment of CAAC’s continued qualification.
The TIP specifically identifies feedback obtained from validation projects as one source of information for continued qualification. If, during a validation exercise, the Validating Authority observes a deficiency in the Certificating Authority’s certification or oversight system, that deficiency is documented and brought to the attention of the COB.
There is therefore a clear two-way feedback relationship. The outcome of initial and continued qualification assessments is one of the factors that can influence the Validating Authority’s level of involvement, while observations made during validation projects can in turn provide input to continued qualification assessments.
For the C919, therefore, the practical question is no longer how to reduce EASA’s level of involvement. The more relevant question is how to improve the efficiency with which each issue is closed when EASA’s level of involvement is objectively bound to remain high.
What, then, can the applicant do proactively in an environment where the Validating Authority is necessarily exercising a high level of involvement?
For a project such as the C919, where EASA’s level of involvement is inherently high because this is a first validation, closure of individual issues is already more complex than in projects conducted under a mature validation relationship. The special scrutiny of the Certificating Authority’s processes and methods adds another dimension to issue closure beyond the technical merits of the design itself.
But regardless of changes in the external environment surrounding a validation project, obtaining validation of the type certificate ultimately still depends on closing individual issues one by one. For the applicant, what remains within its direct control is how effectively those issues are resolved and closed.
In a mature, low-involvement validation project, many issues are primarily matters of technical clarification. In a high-involvement project, however, EASA is concerned not only with the technical result itself. It must also determine whether the material can support its own validation determination under the applicable VA certification basis and in light of CAAC’s original certification rationale.
The same technical material may have been sufficient to support closure during CAAC type certification. Once it enters the EASA validation process, however, it must also address the issues relevant under the VA certification basis and explain the basis on which CAAC made the relevant compliance determination.
Risk management in a high-involvement project therefore depends on identifying each issue’s conditions for closure as early as possible, and organizing technical material, responsibilities and communication strategy accordingly. Submitting more responses does not necessarily mean that the project is making more progress. Technical work becomes genuine project progress only when successive responses narrow the gaps between the parties’ positions on the nature of the issue, the adequacy of the supporting material and the conditions for closure.
This requires the project engineering team to possess two related but distinct capabilities.
The first is engineering capability, which primarily addresses whether the design is sound, whether the analysis is adequate and whether the testing provides sufficient coverage.
The second is the ability to conduct technical negotiation around validation issues. This article refers to it as technical negotiation capability.
Technical negotiation, in this context, means communicating fully with EASA to accurately understand its actual concerns and, on that basis, helping the applicant, CAAC and EASA converge on a compliance solution that can support issue closure.
Technical negotiation is by no means bargaining over safety standards. Nor is it simply a matter of improving the technique of technical responses. It means, first of all, not treating validation as a simple procedural cycle in which “EASA raises a question, the applicant prepares material, and then waits for EASA to accept it.” The applicant needs to understand why EASA has raised the issue, what concern or risk judgement lies behind it, and why the existing proposal is still insufficient to support closure.
The safety objectives of airworthiness certification are not negotiable, but there is not always a single technical or compliance path to achieving those objectives. If the original approach proves difficult to accept, it becomes necessary to consider whether a new path to closure can be established through additional analysis or testing, changes to the means of compliance, compensating design measures, operational limitations, or some combination of these measures, while still meeting the same safety objective.
The core of technical negotiation is therefore not to “persuade EASA to lower its requirements”. It is to facilitate the development of a solution that is technically sound, supported from an airworthiness perspective, implementable from an engineering perspective and acceptable to the Validating Authority, while keeping the safety objective unchanged.
This capability requires familiarity with EASA’s certification procedures and technical standards. It also requires an understanding of EASA’s review approach, decision-making logic and working methods in specific validation projects. The latter cannot normally be acquired from regulations and procedural documents alone. It generally comes from extensive first-hand experience with EASA certification and validation projects. Without such understanding, even a team with strong engineering capability may fail to identify EASA’s actual concerns or the conditions for closure, resulting in substantial time being consumed by repeated rounds of responses.
A team may possess very strong engineering capability, but if its technical responses remain mechanically focused on individual regulatory provisions, without sufficient communication with EASA or a compliance argument structured around EASA’s actual concerns, the issue may still be difficult to close quickly. Conversely, communication with the Validating Authority without robust engineering design, analysis, testing and compliance evidence cannot produce a solution that the authority can genuinely accept.
Risk management under a high level of involvement therefore requires a shift from passive responses towards more proactive technical negotiation.
This proactive management responsibility rests primarily with the applicant. The TIP assigns the applicant responsibility for proposing a realistic time-scale throughout the validation phases, seeking concurrence from the Certificating Authority and the Validating Authority, and taking appropriate action with both authorities to remain as close as possible to the agreed schedule.
In practice, that project-management responsibility also requires the applicant to work proactively with the relevant parties to develop a viable path to issue closure.
From this perspective, the applicant’s technical negotiation capability directly affects both the efficiency of the validation project and the pace at which individual issues can be closed.
What, then, can each party do to support smooth progress of the validation project?
In the actual implementation of the C919 validation project, Validation Plans, or VPs, are established for the principal areas of review. Specific reviews are then conducted through Certification Review Items, or CRIs, and Certification Action Items, or CAIs.
When EASA raises an issue, the applicant should look beyond its immediate technical content and determine what type of issue it actually is:
Is it a technical clarification within the existing scope of the validation project, or does it reflect a new technical concern?
Does it relate to the design itself, the means of compliance, or the original certification process?
Does it involve a difference between the CAAC certification basis and the VA certification basis?
Should the relevant compliance determination in principle be made by CAAC, or has EASA retained the issue and will decide whether it can be closed based on subsequent responses?
Which materials should be provided by the applicant, and which matters require CAAC to make or explain a compliance determination?
Is it a project-level technical issue, or has it begun to involve differing interpretations of the division of responsibilities under the BASA and TIP?
The earlier these determinations are made, the more effective the subsequent work can be.
Technical material developed during CAAC type certification is not automatically material that can be used directly in an EASA validation project.
In addition to demonstrating that something “was done during the CAAC certification”, the material must, once entered into EASA validation, explain which requirement in the VA certification basis it addresses, whether it covers differences between the CAAC and EASA certification bases, why CAAC accepted the relevant means of compliance, and whether the existing material is sufficient for EASA to close the issue. For issues retained by EASA, it is also necessary to assess in advance the gap between the available material and the conditions for closure, and determine whether additional testing, analysis, explanation or confirmation at the level of the Certificating Authority is required.
If engineering material, test reports, statements of compliance and CAAC compliance determinations are not organized according to the logic required for EASA validation closure, and if the relationship between them is not clearly established, EASA does not see a coherent chain of evidence that can support issue closure. Technical completeness does not automatically make material usable for validation. This distinction is easily underestimated by applicants in high-involvement projects.
Under the BASA and TIP framework, the C919 validation is not a process in which the applicant deals with EASA alone. In principle, EASA is expected, at an appropriate level of involvement, to base its validation to the maximum extent practicable on the technical evaluations, tests, inspections and compliance certifications made by CAAC as the Certificating Authority.
Therefore, when an issue involves CAAC’s original certification rationale, the applicant can prepare materials, clarify technical matters and provide additional justification, but it cannot completely replace CAAC in its role as the Certificating Authority.
For CAAC, the task under a high level of involvement is to present the original certification rationale clearly. This includes how the certification basis was established, how means of compliance were accepted, how deviations and equivalent safety findings were assessed and handled, how issues were closed, and which compliance determinations support the final statement of compliance.
Explaining these matters clearly does more than help the applicant respond to EASA. It also helps EASA determine whether it can rely on CAAC’s existing compliance determinations. More broadly, in the first validation of a large transport aircraft, it allows CAAC to demonstrate through an actual project the capability and credibility of its certification system, thereby supporting mutual confidence between the two sides.
A higher level of involvement does not displace the underlying BASA and TIP objective of avoiding unnecessary duplication while protecting safety.
The higher the level of involvement, therefore, the more important it is for EASA to distinguish clearly between matters that are subject to general review, matters that have developed into review issues requiring action by the applicant, issues retained by EASA for a closure decision based on the applicant’s response, matters that can be reviewed on the basis of existing CAAC compliance determinations, and matters requiring further direct verification by EASA.
The clearer these boundaries are, the easier it becomes for the applicant and CAAC to prepare effective material. The clearer the conditions for closure are, the easier it becomes for the project to establish stable expectations. Conversely, if the boundaries are unclear, the applicant will struggle to determine how much additional material is required, CAAC will struggle to determine when its confirmation is needed, and the project can lose substantial time through repeated supplementation.
Technical negotiation matters because issue closure often requires three different types of logic to be aligned at the same time. From an engineering perspective, there must be design, data, testing and analysis. From an airworthiness perspective, the work must correspond to the certification basis, the means of compliance and the conditions for closure. Within a bilateral validation, it must also account for the division of responsibilities, the respective levels of involvement and the mutual reliance between CAAC and EASA.
If these three forms of logic are not effectively connected, the engineering team may believe the issue has been fully explained, CAAC may believe the original certification already covered it, while EASA may still conclude that it lacks sufficient basis to close the issue.
Ultimately, issue closure under a high level of involvement is sometimes not simply a matter of completing a technical response. Where there is no single compliance path, it may require technical negotiation to develop a solution that is technically sound, supported from an airworthiness perspective, implementable from an engineering perspective and ultimately acceptable to EASA.
Returning to the starting point of this article, two different aspects need to be kept distinct.
The first arises from the project itself. As EASA’s first validation of a CAAC type certificate in this product category, the C919 is, under the BASA and TIP, subject to special procedures and scrutiny and a higher level of involvement, including closer attention to the Certificating Authority’s processes and methods.
The second concerns the broader BASA and TIP bilateral relationship in which the C919 project is taking place. Continued mutual confidence is fundamental to the functioning of this framework. The two sides are currently facing disagreements over the implementation of the BASA and TIP, but based on publicly available information, it is not yet possible to determine whether these disagreements have affected EASA’s confidence in CAAC, its assessment of CAAC’s continued qualification, or the C919 project itself.
Accordingly, when an issue in the C919 validation project is closed on a solid basis, this means more than the applicant having completed another technical response. It means that the applicant’s design material, CAAC’s compliance determinations and EASA’s validation determination have been brought into alignment around the same compliance logic. Only when a number of key issues are progressively closed in this manner can the process further translate into project-level confirmation by the two sides of each other’s procedures and capabilities.
This is the practical meaning of maintaining mutual confidence under the BASA and TIP framework. Mutual confidence is not merely a concept written into an agreement. It is built and maintained in individual projects through the ability of the applicant’s material, CAAC’s compliance determinations and EASA’s validation determinations to connect reliably with one another.
Seen from this perspective, the significance of the C919 type certificate validation project extends beyond obtaining an EASA type certificate.
It provides an important practical test of three interfaces: the maturity and usability of the compliance evidence developed for a Chinese large transport aircraft; the extent to which CAAC’s certification findings can be understood and relied upon in an international validation context; and the ability of the EU and China to manage a complex validation under the BASA and TIP framework.
For the project itself, however, this system-level test ultimately comes back to whether individual issues can be closed. The value of technical negotiation capability lies precisely in its ability to connect the applicant’s engineering work, CAAC’s certification rationale and EASA’s validation requirements, so that findings of compliance already established in one system can be understood and examined by another regulatory system, and ultimately translated into validation determinations that support issue closure.
In a C919 project defined by first-validation scrutiny and a necessarily high level of Validating Authority involvement, technical negotiation is an important condition for turning technical work into tangible validation progress.
If the signing of the BASA and TIP established the institutional starting point for EU-China airworthiness cooperation, then the C919 validation project is a concentrated test of this system within a complex, real-world project.
For the Chinese aviation industry, the true long-term challenge is not just designing and certifying an aircraft, but ensuring that the established design materials, means of compliance, and certification conclusions can be fully understood and reasonably relied upon by the international recognition system to ultimately form a validation judgment.
The experience gained from this project may also shape how other validating authorities approach future Chinese certification projects involving civil aircraft, engines, airborne systems and novel aviation products.
In the author’s view, this may be the deeper significance of the C919 type certificate validation project.
Comments, corrections and professional discussion are welcome. If you have thoughts on the issues raised in this article, please feel free to contact the author at wu.yunzhe@tianlux.com.
