Airworthiness Directive 2026-04281

recurring
AD 2026-04281 · 2026-03-04 · reciprocating engine

Airworthiness Directives; Lycoming Engines

What this AD requires

The FAA is superseding Airworthiness Directive (AD) 2024-21- 02, which applies to Lycoming Engines (Lycoming) model engines that have certain connecting rod assemblies installed. AD 2024-21-02 required repetitive oil inspections for bronze metal particulates and, if found, additional inspections of the connecting rod bushings for damage, proper fit, movement, and wear, and replacement if necessary. As terminating action to the connecting rod bushing inspections, AD 2024-21-02 also required replacement of the connecting rod bushings with parts eligible for installation. Since the FAA issued AD 2024-21- 02, the ship date range for potentially affected parts that may be subject to connecting rod failure has been expanded, and additional parts that are eligible for installation have been identified. This AD requires the actions in AD 2024-21-02 and expands the applicability. The FAA is issuing this AD to address the unsafe condition on these products.

Repetitive inspection. Re-inspect. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2026-04281 applies to

MakesLycoming
ModelsAEIO-580-B1A, HIO-390-A1A, HIO-540-A1A, IVO-360-A1A, IVO-540-A1A, AEIO-320, AEIO-360, AEIO-390, AEIO-540, AIO-320, AIO-360, HIO-360, HO-360, IO-320, IO-360, IO-390, IO-540, IO-580, IO-720, LHIO-360
Part-conditionalLW-13923, LW-11750, 78030, LW-19332, LW-13865, 77450, LW-13422, LW-13937.

Applies only to Lycoming engine models known to have one of the affected connecting rod part numbers (Table 1) installed, where the engine was assembled within the ship date range of 01/30/2009-09/09/2021 for that part number.

Whether AD 2026-04281 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.

How AD compliance is recorded

A valid compliance record (14 CFR 43.9) states:

Method of complianceThe specific action taken (inspected, replaced, modified) and to what revision.
DateWhen the work was done.
Aircraft timeTotal time in service / tach at compliance — how recurring next-due is computed.
Signature & certificateThe A&P/IA who returned it to service, with certificate number.
Is AD 2026-04281 complied with on your aircraft?

Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.

Look up a tail number →Read the full directive (Federal Register)

Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.