Summary
We propose to supersede Airworthiness Directives (AD) 2006-21- 08, AD 2007-14-01, AD 2008-25-02, AD 2010-04-09, AD 2011-01-02, and AD 2012-16-05, for certain Airbus Model A330 and 340 series airplanes. AD 2006-21-08, AD 2007-14-01, AD 2008-25-02, AD 2010-04-09, AD 2011-01-02, and AD 2012-16-05 currently require revising the maintenance program or inspection program to incorporate certain maintenance requirements and airworthiness limitations for fuel tank systems. Since we issued AD 2006-21-08, AD 2007-14-01, AD 2008-25-02, AD 2010-04-09, AD 2011-01-02, and AD 2012-16-05, we have determined that more restrictive maintenance requirements and airworthiness limitations are necessary. This proposed AD would require a new maintenance or inspection program revision. We are proposing this AD to prevent the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.