Federal Aviation Administration February 18, 2016 – Federal Register Recent Federal Regulation Documents

We propose to supersede Airworthiness Directive (AD) 2011-01- 15, which applies to certain The Boeing Company Model 757-200, -200CB, and -300 series airplanes. AD 2011-01-15 currently requires repetitive inspections for cracking of the fuselage skin of the crown skin panel along the chem-milled step at stringers S-4L (left) and S-4R (right), from stations (STA) 297 through STA 439, and repair, if necessary. AD 2011-01-15 also includes terminating action for the repetitive inspections of the repaired areas only. Since we issued AD 2011-01-15, we received reports of the initiation of new fatigue cracking in the fuselage skin of the crown skin panel along locally thinned channels adjacent to the chem-milled steps. This proposed AD would add repetitive inspections for cracking in additional areas and repair if necessary. This proposed AD would also remove airplanes from the applicability in AD 2011-01-15. This proposed AD would also add an optional skin panel replacement which would terminate all inspections and an optional preventative modification that would terminate certain inspections. We are proposing this AD to detect and correct fatigue cracking of the fuselage skin of the crown skin panel, which could result in pressure venting and consequent rapid decompression of the airplane.

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-400F series airplanes. This AD was prompted by an analysis of the production methods used to increase fatigue resistance of the upper closure fittings at the nose cargo door portal's C-3 frame, which showed that cracking could start too early to be caught in a timely manner by the inspection or maintenance program. This AD requires inspections of the upper closure fitting and connected strap and doubler at the nose cargo door portal for cracking, and related investigative and corrective actions if necessary. We are issuing this AD to detect and correct such cracking, which could result in sudden decompression and loss of the airplane's structural integrity.

We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model 777 airplanes. This proposed AD was prompted by a report of an incident involving a landing in which the pilots needed to input corrections due to airplane yaw and roll to the right; the main landing gear (MLG) aft trunnion pin was later found to be fractured. This proposed AD would require identification and replacement of certain MLG aft trunnion pins. We are proposing this AD to prevent a fractured MLG aft trunnion pin, which could result in collapse of the MLG and consequent loss of control of the airplane during landing.

We propose to adopt a new airworthiness directive (AD) for all Fokker Services B.V. Model F.28 Mark 0070 and 0100 airplanes. This proposed AD was prompted by the need for more restrictive airworthiness limitations. This proposed AD would require revising the maintenance program or inspection program, as applicable, to incorporate certain maintenance requirement tasks, thresholds, and intervals. We are proposing this AD to reduce the potential for significant failure conditions and consequent loss of controllability of the airplane.