Airworthiness Directives; Continental Aerospace Technologies, Inc., Reciprocating Engines

The FAA is superseding Airworthiness Directive (AD) 2023-04-08 which applied to certain Continental Aerospace Technologies, Inc. (Continental) GTSIO-520-C, -D, -H, -K, -L, -M, -N, and -S; IO-360-A, - AB, -AF, -C, -CB, -D, -DB, -E, -ES, -G, -GB, -H, -HB, -J, -JB, -K, and -KB; IO-470-D, -E, -G, -H, -J, -K, -L, -M, -N, -P, -R, -S, -T, -U, -V, and -VO; IO-520-A, -B, -BA, -BB, -C, -CB, -D, -E, -F, -J, -K, -L, -M, and -MB; IO-550-A, -B, -C, -D, -E, -F, -G, -L, -N, -P, and -R; LTSIO- 360-E, -EB, -KB, and -RB; LTSIO-520-AE; O-470-A, -B, -E, -G, -H, -J, - K, -L, -M, -N, -R, -S, -T, and -U; TSIO-360-A, -AB, -B, -BB, -C, -CB, - D, -DB, -E, -EB, -G, -GB, -H, -HB, -JB, -KB, -LB, -MB, -RB, and -SB; TSIO-520-A, -AE, -AF, -B, -BB, -BE, -C, -CE, -D, -DB, -E, -EB, -G, -H, -J, -JB, -K, -KB, -L, -LB, -M, -NB, -P, -R, -T, -UB, -VB, and -WB; TSIO-550-A, -B, -C, -E, -G, -K, and -N; TSIOF-550-K; and TSIOL-550-A, - B, and -C model reciprocating engines. AD 2023-04-08 required inspection of the crankshaft assembly for proper installation of the counterweight retaining rings in the counterweight groove and, depending on the results of the inspection, corrective actions if improper installation was found. This AD continues to require inspection of the crankshaft assembly for proper installation of the counterweight retaining rings in the counterweight groove, and corrective actions if improper installation is found. Since the FAA issued AD 2023-04-08, operators notified the FAA, and Continental confirmed, that certain affected model reciprocating engines not included in the applicability of AD 2023-04-08 are also affected by the unsafe condition. Additionally, the FAA determined the special flight permit paragraph required revision. This AD was prompted by a report of a quality escape involving improper installation of counterweight retaining rings in the engine crankshaft counterweight groove during manufacture. The FAA is issuing this AD to address the unsafe condition on these products.