FAA Proposes Updated CFM56-7B Fan Blade Inspections — Why the Real Driver Isn't the Headline Incident

On July 31, 2026, the FAA published a proposed airworthiness directive (Docket No. FAA-2026-15532) that would supersede AD 2018-26-01 — the directive written after the April 2018 Southwest Airlines Flight 1380 accident, in which a fractured CFM56-7B fan blade tore through the engine cowling, depressurized the cabin, and caused a fatality. The proposal is open for comment through August 31, 2026, on a compressed 30-day schedule instead of the usual 45. What's easy to miss in coverage connecting this to a July engine failure on a Ryanair-operated 737 is that the FAA itself says it has no evidence the two are actually related.

What the proposed AD actually changes. AD 2018-26-01 already requires initial and repetitive ultrasonic or eddy current inspection of certain CFM56-7B fan blade dovetails for crack indications, with replacement if cracks are found. This proposal doesn't rewrite that framework — it updates it to match CFM International's Service Bulletin 72-1033, Revision 5 (dated July 28, 2026), which improves the ultrasonic inspection procedure and expands the area of the blade being inspected.

The incident everyone's citing isn't the reason for the change. On July 10, 2026, a Boeing 737-800 operating as Malta Air/Ryanair flight FR1879 suffered an apparent uncontained failure of its right CFM56-7B engine during a flight from Thessaloniki to Memmingen. The cause remains under investigation. But the FAA's own proposal states plainly that it has received no factual information indicating the incident is related to the unsafe condition this AD addresses. The shortened comment period is explained instead by a need to align implementation timing with EASA — the incident's timing is acknowledged, not cited as the trigger.

Still a proposal, not a mandate — for now. As of the August 31 comment deadline, this is an NPRM, not a final rule. AD 2018-26-01's existing ultrasonic/eddy current dovetail inspection requirements remain in force unchanged until the FAA finalizes this proposal and establishes an actual compliance date. Shops with CFM56-7B engines in the fleet don't have a new inspection obligation yet — but the direction is clear enough that waiting for the final rule to review procedures against the new service bulletin would be cutting it close.

This is exactly the kind of dovetail-region ultrasonic and eddy current work Lion NDT's Ultrasonic Testing services are built around — precise, code-compliant inspection to whichever revision of the governing service bulletin actually applies, not just the one your last audit was checked against. If your shop is tracking CFM56-7B fan blade inspections, this is a good moment to confirm your procedures already reflect SB 72-1033 Revision 5 rather than waiting for the final AD to force the question.