The Engine Came Back Clean. The Operator's Lawyers Said Otherwise.

An independent MRO facility — FAA and EASA Part 145 certified, servicing CFM56-7B engines for narrow-body commercial operators — completes a full workscope restoration and returns the engine to the operator. The work is correct. The test cell data confirms the engine performed within specification at return.

Six weeks later, the operator files a warranty claim alleging the engine was returned in degraded condition, pointing to an EGT exceedance event during the first post-return revenue flight. The MRO's test cell data is stored in proprietary software — not sealed, not cryptographically timestamped, not producible in a format that survives legal scrutiny. Opposing counsel argues it could have been modified after the fact.

The workscope value is $1.8 million USD. The operator's warranty claim is $2.2 million. The MRO's only defense is the word of their test cell technician and an Excel export with no chain of custody.

With Shabboo Black Box installed, the same engine return generates a cryptographically sealed forensic evidence package the moment the run completes. Every sensor channel — EGT, N1, N2, fuel flow, vibration — is compared against the CFM56-7B design baseline and classified by severity. The SHA-256 sealed manifest is generated automatically. Any post-run modification produces a detectable hash mismatch.

The sealed forensic package demonstrates conclusively that all monitored sensor channels were within nominal or advisory range at return. The EGT exceedance that occurred six weeks later is traceable to post-return operating conditions — not to the MRO's workscope. The claim is withdrawn.