Airworthiness review reports: what can blockchain prove?

An airworthiness review report explains what was checked on an aircraft and the outcome. To retrieve and examine it years later, start by preserving the complete report, its supporting records and the identities of those involved. Blockchain can add a way to check file integrity, but it cannot replace that record set.

The report and the certificate have different jobs

An airworthiness review combines a review of records with a physical survey of the aircraft. The ARC, or Airworthiness Review Certificate, is issued through that process when the necessary conditions are met. The report records the details and outcome. It is not another name for the ARC.

Since 7 August 2026, M.A.903(h) and ML.A.903(h) explicitly require this record. Regulation (EU) 2026/100 also requires the relevant organisations to keep the report with the ARC or the recommendation sent to the authority for issuance. It does not mandate blockchain.

The archive itself remains regulated: CAMO.A.220(d) to (f) requires reliable traceability, a format defined in the organisation’s procedures and protection against damage, alteration and theft. CAO.A.090(d) and (e) also requires record protection and physical separation of computer backups. These requirements apply independently of any distributed ledger. Source: Regulation 1321/2014 consolidated to 7 August 2026.

AMC1 M.A.903(h), pages 23 to 25, describes an acceptable means of compliance: aircraft and personnel details, records reviewed, areas surveyed, findings, action taken and the conclusion. An AMC sets out an acceptable way to meet a rule. It does not make a particular software product compulsory.

Establish the retention period for each role

A CAMO is a continuing airworthiness management organisation. A CAO is a combined airworthiness organisation whose permitted activities depend on its approval. For these organisations, CAMO.A.220(a)(3), (6) and (7), and CAO.A.090(a)(4) and (c), distinguish two situations:

• In the management role, copies of the report and certificate or recommendation must, among the applicable record requirements, be retained for three years after management is transferred to another person or organisation.
• If the issuing organisation is different from the organisation managing continuing airworthiness, it keeps these records and supporting documents for five years from issuance.

The report date alone therefore does not determine the retention period. Identify each organisation’s role and the event that starts the clock. Record transfer requirements also remain relevant. Source: Annexes V and VI of Regulation 2026/100.

What a fingerprint can verify

A cryptographic fingerprint, or hash, is a short value calculated from a file’s contents. That value can be recorded in a ledger. Someone receiving the file can calculate its hash again and check for a match. With a suitable algorithm, a change to the file will normally be detected.

The NIST blockchain overview describes ledgers designed to make tampering detectable and difficult. Section 7.1 also explains that immutability is not absolute. The protection depends on the network and its governance. A date’s reliability also depends on the timestamping mechanism.

Matching fingerprints do not demonstrate that an inspection happened, that the initial content was correct or that the signer was authorised. Nor can a fingerprint recreate a lost report. If only the hash is recorded in the ledger, the file still needs a separate archive. Confidentiality depends on what is published and who can access the records, not on the blockchain label.

Test retrieval before choosing a tool

Our recommendation is to test a complete retrieval: can an authorised person find the report, supporting documents and final version, then understand who concluded what and when? Check how corrections are handled and whether records can be exported when changing providers.

If you add a ledger entry, document who makes it, how identity is linked to the document and how a third party verifies the fingerprint. These are tool selection criteria, not additional technology requirements from EASA. Our explanation of Regulation 2026/100 covers the conditions for issuing and extending an ARC.