Airworthiness Directives; Fokker Model F28 Mark 0100 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 series airplanes, that requires inspections to detect cracking of the Hi-lok bolt holes in the main hinge fittings of the horizontal stabilizer, and repair, if necessary. The amendment also requires modification of the main hinge fitting, modification or replacement of rib connecting angles, and modification of ribs. This amendment is prompted by a report indicating that cracking was found in the main hinge fittings of the horizontal stabilizer during fatigue testing. The cracking was a result of higher- than-anticipated loads induced during operation of the thrust reverser. The actions specified by this AD are intended to prevent deterioration of the fatigue life of the main hinge fittings of the horizontal stabilizer and reduced structural integrity of the horizontal stabilizer due to higher induced loads.