Airworthiness Directives; Goodrich Avionics Systems, Inc. TAWS8000 Terrain Awareness Warning System

The FAA supersedes Airworthiness Directive (AD) 2003-13-08, which currently applies to all Goodrich Avionics Systems, Inc. (Goodrich) TAWS8000 terrain awareness warning systems (TAWS) that are installed on airplanes. AD 2003-13-08 currently requires you to inspect the TAWS installation and remove any TAWS where both the TAWS and any other device are connected to the same baro set potentiometer. AD 2003- 13-08 also prohibits future installation of any TAWS8000 TAWS that incorporates hardware "Mod None", "Mod A", or "Mod B". This AD is the result of omitting from AD 2003-13-08 a provision that prohibits reconfiguring an installed TAWS8000 TAWS after it passes the inspection unless it incorporates hardware "Mod C". This AD retains the actions of AD 2003-13-08 and prohibits future installation or reconfiguration of any TAWS8000 TAWS that does not incorporate hardware "Mod C". We are issuing this AD to prevent the loading of the baro set potentiometer, which could result in an unacceptable altitude error. That condition could cause the pilot to make flight decisions that put the airplane in unsafe flight conditions.