Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI (two different MCAI) describe the unsafe conditions as:
FOCA AD HB 2002-271 was issued because the Nose Landing Gear (NLG) Right Hand (RH) upper drag link, Part Number (P/N) 532.20.12.140 was found broken on some aircraft due to fatigue cracking, and therefore a life limit of 4,000 landings was introduced. Recent investigation of a new occurrence revealed that the replacement part NLG RH upper drag link P/N 532.20.12.289 also suffered fatigue cracking, however on a different location. Complete failure of the NLG RH upper drag link could result in NLG collapse during landing.
and
This Airworthiness Directive (AD) is prompted byreports of several in-service cracked torque tubes. A reduced wall thickness produced during the manufacturing process has been determined to be the initial cause. Additionally, all the involved torque tubes have been found to show fatigue cracking problems. Such a condition, if left uncorrected, could lead to failure of the torque tube and result in loss of the steering control on ground and consequent unsafe condition.
The proposed AD would require actions that are intended to address the unsafe conditions described in the MCAI.