Summary
We propose to supersede Airworthiness Directive (AD) 2008-17- 02, AD 2012-08-03, and AD 2012-15-14, for certain Airbus Model A300 B4- 2C, B4-103, and B4-203 airplanes; Model A300 B4-600, B4-600R, and F4- 600R series airplanes, and Model C4-605R Variant F airplanes (collectively called A300-600 series airplanes); and Model A310 series airplanes. AD 2008-17-02, AD 2012-08-03, and AD 2012-15-14 currently require repetitive inspections of the forward lugs of the aft bearing at rib 5 of the main landing gear (MLG) on the left-hand (LH) and right-hand (RH) wings, and repair if necessary; and installation of new bushes with increased interference fit in the forward lug of the aft bearing at rib 5 of the MLG on the LH and RH wings. Since we issued AD 2008-17-02, AD 2012-08-03, and AD 2012-15-14, we have received two reports of ruptured MLG rib 5 forward lugs that had been modified (bushes with increased interference fit). This proposed AD would add airplanes to the applicability; andwould add, for certain airplanes, repetitive inspections of the MLG rib 5 aft bearing forward lugs, and repair if necessary. We are proposing this AD to detect and correct cracking of the forward lugs of the aft bearing at rib 5 of the MLG on the LH and RH wings, which could affect the structural integrity of the MLG attachment, resulting in possible MLG collapse during landing or rollout.