Federal Aviation Administration February 10, 2014 – Federal Register Recent Federal Regulation Documents

We are revising an earlier proposed airworthiness directive (AD) for all Airbus Model A318 series airplanes, and Model A319, A320, and A321 series airplanes. The NPRM proposed identifying the part number and serial number of each passenger oxygen container, replacing the oxygen generator manifold of the affected oxygen container with a serviceable manifold, and performing an operational check of the manual mask release, and corrective actions if necessary. The NPRM was prompted by reports of silicon particles inside the oxygen generator manifolds, which had chafed from the mask hoses during installation onto the generator outlets. This action revises the NPRM by adding airplanes to the applicability, adding a new check for part numbers, corrective actions if necessary, and reducing the compliance time for certain actions. We are proposing this AD to detect and correct non- serviceable oxygen generator manifolds, which could reduce or block the oxygen supply and result in injury to passengers when oxygen supply is needed. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.

We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model 707 airplanes, and Model 720 and 720B series airplanes. This proposed AD was prompted by reports of scribe-line- related fatigue cracks on Model 727 airplanes, which are similar in design to Model 707 airplanes, and Model 720 and 720B series airplanes. This proposed AD would require inspections for scribe lines in the skin lap joints, external approved repairs, external features, skin butt joints, and decals, and related investigative and corrective actions if necessary. This proposed AD would also require surface finish restoration. We are proposing this AD to detect and correct scribe lines, which can develop into fatigue cracks in the skin and cause rapid decompression of the airplane.

We propose to supersede Airworthiness Directive (AD) 98-13-23, which applies to certain Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes (collectively called Model A300-600 series airplanes). AD 98-13-23 requires inspections to detect corrosion and cracking of the lower horizontal stabilizer cutout longeron, the corner fitting, the skin strap, and the outer skin; and repair, if necessary. Since we issued AD 98-13-23, we have determined that the risk of cracking is higher than initially determined. This proposed AD would reduce the compliance times and repetitive intervals, and changes the inspection procedures. We are proposing this AD to prevent cracking of the lower horizontal stabilizer cutout longeron, the corner fitting, the skin strap, and the outer skin, which could result in reduced structural integrity of the horizontal-stabilizer cutout longeron.