Federal Aviation Administration September 5, 2018 – Federal Register Recent Federal Regulation Documents

These amended special conditions are issued for the Boeing Model 747-8 airplane. This amendment states that the Boeing Model 747-8 airplane oblique (side-facing) seats may be installed at an angle of 18 to 45 degrees to the airplane centerline and may include a 3-point or airbag restraint system, or both, for occupant restraint and injury protection. Additionally, this amendment changes paragraphs 4 through 8 of the special conditions section. This airplane will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. These design features are oblique (side-facing) single- occupant seats equipped with or without airbag devices or 3-point restraints. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional safety standards the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

We are superseding Airworthiness Directive (AD) 2013-02-04 for all Rolls-Royce plc (RR) RB211-Trent 970-84, RB211-Trent 970B-84, RB211-Trent 972-84, RB211-Trent 972B-84, RB211-Trent 977-84, RB211- Trent 977B-84, and RB211-Trent 980-84 turbofan engines. AD 2013-02-04 required on-wing inspections of low-pressure turbine (LPT) disk seal fins and interstage seals when post-flight review indicates Engine Health Monitoring (EHM) vibratory maintenance-alert limits were exceeded in flight. This AD requires additional criteria for the inspection of the stage 2, 3, and 4 LPT disk seal fins and interstage seals and removes the requirement to inspect the stage 5 LPT disk seal fins and interstage seal. This AD was prompted by a Trent 900 engine experiencing increased low-pressure rotor vibration while in flight resulting in an in-flight shutdown (IFSD) and air turnback. We are issuing this AD to address the unsafe condition on these products.

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the longitudinal lap splices of the fuselage skin are subject to widespread fatigue damage (WFD). This AD requires repetitive inspections of the longitudinal lap splices of the fuselage skin for cracking and protruding fasteners, and applicable corrective actions. We are issuing this AD to address the unsafe condition on these products.