AD NUMBER: 2008-04-02
SUBJECT: Airworthiness Directive 2008-04-02 SUMMARY: The FAA is
adopting a new airworthiness directive (AD) for certain Bombardier
Model DHC-8-400 series airplanes.
This AD requires inspecting all barrel nuts to determine if the
barrel nuts have a certain marking, inspecting affected bolts to
determine if the bolts are pre-loaded correctly, and replacing all
hardware if the pre-load is incorrect. For airplanes on which the
pre-load is correct, this AD requires doing repetitive visual
inspections for cracking of the barrel nuts and cradles and
replacing all hardware for all cracked barrel nuts.
This AD also requires replacement of all hardware for certain
affected barrel nuts that do not have cracking, which would end the
repetitivei nspections for those airplanes. This AD also provides
an optional replacement for all affectedbarrel nuts.
This AD results from reports of cracking in the barrel nuts at
the four primary front spar wing-to-fuselage attachment joints.
We are issuing this AD to detect and correct cracking of the
barrel nuts at the wing front spar wing-to-fuselage joints, which
could result in reduced structural integrity of the
wing-to-fuselage attachments and consequent detachment of the