AD 98-01-01 63 FR 3455

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 98-01-01, which was sent previously to all known U.S. owners and operators of certain Cessna Aircraft Company (Cessna) Models 172R and 182S airplanes. This AD requires fabricating and installing placards to prohibit operation in instrument flight rules (IFR) conditions and use of the alternate static air source; inspecting the alternate static air source valve to assure that the alternate static air source port is not restricted by the identification placard and to assure that the valve body does not separate from the valve flange; and reworking or replacing as necessary. The AD was the result of reports of improper installation of the identification placard on the alternate static air source. The actions specified by this AD are intended to prevent erroneous indications from the altimeter, airspeed, and vertical speed indicators, which could cause the pilot to react to incorrect flight information and possibly result in loss of control of the airplane.