Franklin 6A

Airworthiness Directives; Wytwornia Sprzetu Komunikacyjnego (WSK) PZL-Rzeszow S.A. Franklin 6A-350-C1, -C1A, -C1L, -C1R -C2, -C2A, and 4A-235 Series Reciprocating Engines

This amendment supersedes an emergency airworthiness directive (AD) that was sent previously to all known U.S. owners and operators of WSK PZL-Rzeszow S.A. Franklin 6A-350-C1, -C1A, -C1L, -C2, -C2A, and 4A- 235 series reciprocating engines. This action requires removing diaphragm type AC4886 fuel pump, AC part number (P/N) 5656774, PZL P/N 26.11.1710, before further flight, and prohibits installing diaphragm type AC4886 fuel pump, AC P/N 5656774, PZL P/N 26.11.1710. This amendment is prompted by several reports of failures of the valves and diaphragms in certain diaphragm type AC4886 fuel pumps, AC P/N 5656774, PZL P/N 26.11.1710, and adds the 6A-350-C1R engine to the applicability. The actions specified by this AD are intended to prevent reduction or loss of engine power or external fuel leaks.

Airworthiness Directives; Franklin Model 6A4-150-B3 and 6A4-165- B3 Reciprocating Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to Franklin Model 6A4-150-B3 and 6A4-165-B3 reciprocating engines, installed on the following U.S. registered aircraft: N6209M, N74231, and N752C. This action supersedes priority letter AD 94-14-11 that currently requires engines certified to operate on 91 octane or higher avgas to undergo a teardown and analytical inspection for detonation damage, and engines certified to operate on 80 octane avgas to undergo inspection for evidence of possible internal engine damage. This action revises incorrect engine model numbers listed in the priority letter AD. This amendment is prompted by updated information that has identified the correct engine model numbers. The actions specified by this AD are intended to prevent detonation due to low octane, which can result in severe engine damage and subsequent failure.