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Airworthiness Directive

AD 2026-17-10: Reciprocating Engine Cylinder Section

Airworthiness Directives; Lycoming Engines

Effective
Sep 14, 2026
Published
Aug 28, 2026
Registered aircraft
3,551

Models this AD may apply to

AI-extracted — verify against original

Matched from the AD's applicability section. Applicability must be confirmed by a mechanic against the aircraft's records.

Engines

  • LYCOMING IO-540-A1A5
  • LYCOMING IO-540-AA1A5
  • LYCOMING IO-540-AA1B5
  • LYCOMING IO-540-AB1A5
  • LYCOMING IO-540-AC1A5
  • LYCOMING IO-540-AE1A5
  • LYCOMING IO-540-B1A5
  • LYCOMING IO-540-B1B5
  • LYCOMING IO-540-B1C5
  • LYCOMING IO-540-C1B5
  • LYCOMING IO-540-C1C5
  • LYCOMING IO-540-C2C
  • LYCOMING IO-540-C4B5
  • LYCOMING IO-540-C4B5D
  • LYCOMING IO-540-C4C5
  • LYCOMING IO-540-C4D5
  • LYCOMING IO-540-C4D5D
  • LYCOMING IO-540-D4A5
  • LYCOMING IO-540-D4B5
  • LYCOMING IO-540-D4C5
  • LYCOMING IO-540-E1A5
  • LYCOMING IO-540-E1B5
  • LYCOMING IO-540-E1C5
  • LYCOMING IO-540-G1A5
  • LYCOMING IO-540-G1B5
  • LYCOMING IO-540-G1C5
  • LYCOMING IO-540-G1D5
  • LYCOMING IO-540-G1E5
  • LYCOMING IO-540-G1F5
  • LYCOMING IO-540-J4A5
  • LYCOMING IO-540-K1A5
  • LYCOMING IO-540-K1A5D
  • LYCOMING IO-540-K1B5
  • LYCOMING IO-540-K1B5
  • LYCOMING IO-540-K1B5D
  • LYCOMING IO-540-K1C5
  • LYCOMING IO-540-K1D5
  • LYCOMING IO-540-K1E5
  • LYCOMING IO-540-K1E5D
  • LYCOMING IO-540-K1F5
  • LYCOMING IO-540-K1F5D
  • LYCOMING IO-540-K1G5
  • LYCOMING IO-540-K1G5D
  • LYCOMING IO-540-K1H5
  • LYCOMING IO-540-K1J5
  • LYCOMING IO-540-K1K5
  • LYCOMING IO-540-K2A5
  • LYCOMING IO-540-L1A5
  • LYCOMING IO-540-L1A5D
  • LYCOMING IO-540-L1B5D
  • LYCOMING IO-540-L1C5
  • LYCOMING IO-540-M1A5
  • LYCOMING IO-540-M1A5D
  • LYCOMING IO-540-M1B5D
  • LYCOMING IO-540-M1C5
  • LYCOMING IO-540-M2A5D
  • LYCOMING IO-540-N1A5
  • LYCOMING IO-540-P1A5
  • LYCOMING IO-540-R1A5
  • LYCOMING IO-540-S1A5
  • LYCOMING IO-540-T4A5D
  • LYCOMING IO-540-T4B5
  • LYCOMING IO-540-T4C5D
  • LYCOMING IO-540-U1A5D
  • LYCOMING IO-540-U1B5D
  • LYCOMING IO-540-V4A5D
  • LYCOMING IO-540-W1A5
  • LYCOMING IO-540-W1A5D
  • LYCOMING IO-540-W3A5D
  • LYCOMING O-235
  • LYCOMING O-235-C
  • LYCOMING O-235-C1
  • LYCOMING O-235-C1A
  • LYCOMING O-235-C1B
  • LYCOMING O-235-C1C
  • LYCOMING O-235-C2A
  • LYCOMING O-235-C2B
  • LYCOMING O-235-C2C
  • LYCOMING O-235-E1
  • LYCOMING O-235-E1B
  • LYCOMING O-235-E2A
  • LYCOMING O-235-E2B
  • LYCOMING O-235-F1
  • LYCOMING O-235-F1B
  • LYCOMING O-235-F2A
  • LYCOMING O-235-F2B
  • LYCOMING O-235-G1
  • LYCOMING O-235-G1B
  • LYCOMING O-235-G2A
  • LYCOMING O-235-G2B
  • LYCOMING O-235-H2C
  • LYCOMING O-235-J2A
  • LYCOMING O-235-J2B
  • LYCOMING O-235-K2A
  • LYCOMING O-235-K2B
  • LYCOMING O-235-K2C
  • LYCOMING O-235-L2A
  • LYCOMING O-235-L2C
  • LYCOMING O-235-M1
  • LYCOMING O-235-M2C
  • LYCOMING O-235-M3C
  • LYCOMING O-235-N2A
  • LYCOMING O-235-P1
  • LYCOMING O-235-P2A
  • LYCOMING O-235-P2C
  • LYCOMING O-235-P3C
  • LYCOMING O-540-A1A
  • LYCOMING O-540-A1A5
  • LYCOMING O-540-A1B5
  • LYCOMING O-540-A1C5
  • LYCOMING O-540-A1D
  • LYCOMING O-540-A1D5
  • LYCOMING O-540-A2B
  • LYCOMING O-540-A3D5
  • LYCOMING O-540-A4A5
  • LYCOMING O-540-A4B5
  • LYCOMING O-540-A4C5
  • LYCOMING O-540-A4D5
  • LYCOMING O-540-B1A5
  • LYCOMING O-540-B1B5
  • LYCOMING O-540-B1D5
  • LYCOMING O-540-B2A5
  • LYCOMING O-540-B2A5
  • LYCOMING O-540-B2B5
  • LYCOMING O-540-B2C5
  • LYCOMING O-540-B4A5
  • LYCOMING O-540-B4B5
  • LYCOMING O-540-D1A5
  • LYCOMING O-540-E4A5
  • LYCOMING O-540-E4B5
  • LYCOMING O-540-E4C5
  • LYCOMING O-540-F1A5
  • LYCOMING O-540-F1B5
  • LYCOMING O-540-G1A5
  • LYCOMING O-540-G2A5
  • LYCOMING O-540-H1A5
  • LYCOMING O-540-H1A5D
  • LYCOMING O-540-H1B5D
  • LYCOMING O-540-H2A5
  • LYCOMING O-540-H2A5D
  • LYCOMING O-540-J1A5D
  • LYCOMING O-540-J1B5D
  • LYCOMING O-540-J1C5D
  • LYCOMING O-540-J1D5D
  • LYCOMING O-540-J2A5D
  • LYCOMING O-540-J2B5D
  • LYCOMING O-540-J2C5D
  • LYCOMING O-540-J2D5D
  • LYCOMING O-540-J3A5D
  • LYCOMING O-540-J3C5D
  • LYCOMING O-540-L3C5D
  • LYCOMING O235N2C
  • Serial numbers per Table 2 or Table 3 of Lycoming Mandatory Service Bulletin No. 667A, dated March 12, 2026. Only with: Installed piston pin P/N LW-13445 with an OEM FAA Form 8130-3 production dated between January 7, 2021 and December 15, 2025, or where the production date cannot be determined or the form is unavailable.
  • Only with: Installed piston pin P/N LW-13445 with an OEM FAA Form 8130-3 production dated between January 7, 2021 and December 15, 2025, or where the production date cannot be determined or the form is unavailable.

Applicability

From the AD text
This AD applies to Lycoming Engines Model O-235, -A, -AP, -B, -BP, -C, -C1, -C1A, -C1B, -C1C, -C2A, -C2B, -C2C, -E1, -E1B, -E2A, -E2B, -F1, -F1B, -F2A, -F2B, -G1, -G1B, O-235-G2A, O-235-G2B, O-235-H2C, O-235-J2A, O-235-J2B, O-235-K2A, O-235-K2B, -K2C, -L2A, -L2C, -M1, -M2C, -M3C, -N2A, -N2C, -P1, -P2A, -P2C, and -P3C; O-540-A1A, -A1A5, -A1B5, -A1C5, -A1D, -A1D5, -A2B, -A3D5, -A4A5, -A4B5, -A4C5, -A4D5, -A4E5, -B1A5, -B1B5, -B1D5, -B2A5, -B2B5, -B2C5, -B4A5, -B4B5, -D1A5, -E4A5, -E4B5, -E4C5, -F1A5, -F1B5, -G1A5, -G2A5, -H1A5, -H1A5D, -H1B5D, -H2A5, -H2A5D, -H2B5D, -J1A5D, -J1B5D, -J1C5D, -J1D5D, -J2A5D, -J2B5D, -J2C5D, -J2D5D, -J3A5, -J3A5D, -J3C5D, and -L3C5D; IO-540-A1A5, -AA1A5, -AA1B5, -AB1A5, -AE1A5, -AC1A5, -AF1A5, -B1B5, -AG1A5, -B1A5, -B1C5, -C1B5, -C1C5, -C2C, -C4B5, -C4B5D, -C4C5, -C4D5, -C4D5D, -D4A5, -D4B5, -D4C5, -E1A5, -E1B5, -E1C5, -G1A5, -G1B5, -G1C5, -G1D5, -G1E5, -G1F5, -J4A5, -K1A5, -K1A5D, -K1B5, -K1B5D, -K1C5, -K1D5, -K1E5, -K1E5D, -K1F5, -K1F5D, -K1G5, -K1G5D, -K1H5, -K1J5, -K1J5D, -K1K5, -K2A5, -L1A5, -L1A5D, -L1B5D, -L1C5, -M1A5, -M1A5D, -M1B5D, -M1C5, -M2A5D, -N1A5, -P1A5, -R1A5, -S1A5, -T4A5D, -T4B5, -T4B5D, -T4C5D, -U1A5D, -U1B5D, -V4A5, -V4A5D, -W1A5…

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