AD NUMBER:2011-20-04

MANUFACTURER: Gulfstream Aerospace LP Model Galaxy and Gulfstream 200 Airplanes
SUBJECT: Airworthiness Directive
ACTION: Final rule.

SUMMARY: This 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 describes the unsafe condition as:

Cracked nuts ... were found on aircraft's production line during routine post assembly inspection. Investigation revealed that the cracks resulted from hydrogen embrittlement combined with high hardness. Non-conformity with certified mechanical properties of this fastener can potentially lead to an unsafe condition.

The unsafe condition is cracked nuts in multiple locations (including aileron fittings, rudder tab assembly and mounting structure for power drive units) could result in failure of affected locations and consequent reduced controllability or reduced structural capability of the airplane.

DATES: This AD becomes effective November 7, 2011.

FMI: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/3353205EACDDA6EE8625791E00483340?OpenDocument