Federal Aviation Administration February 7, 2014 – Federal Register Recent Federal Regulation Documents

This action proposes special conditions for the Learjet Inc. Model LJ-200-1A10 airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. The fuselage of the LJ-200-1A10 will be made of composite materials rather than conventional aluminum, which may affect fire propagation during an in- flight fire. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

These special conditions are issued for the Learjet Inc. Model LJ-200-1A10 airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This feature is a hybrid construction that uses both composite and metallic materials in the structure for which the crashworthiness responses for occupant safety may not be equivalent to current all-metallic airplanes. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that 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) 2003-19-11 for certain Learjet Inc. Model 60 airplanes. AD 2003-19-11 required determining if a certain fuel crossflow tube is installed; and follow- on/corrective actions, as applicable. This new AD requires retaining all actions in AD 2003-19-11, and it also requires determining if a certain fuel crossflow tube is installed, performing repetitive measurements of the fuel crossflow tube and surrounding valves and cables, and doing corrective actions if necessary. In addition, this new AD expands the applicability of AD 2003-19-11. This AD was prompted by a report that airplanes produced since 2003 might also be subject to the unsafe condition; and that the minimum allowable clearance is not established in the airplane maintenance information. We are issuing this AD to prevent chafing and consequent failure of the fuel crossflow tube due to inadequate clearance between the tube and the flight control cables, which could result in loss of fuel from one fuel tank during normal operating conditions or loss of fuel from both main fuel tanks during fuel cross-feeding operations.

We are adopting a new airworthiness directive (AD) for certain the Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by a report of cracks in stringer splices at body station STA 360 and STA 908, between stringer (S) S-10L and S-10R; cracks in butt straps between S-5L and S-3L, and S-3R and S-5R; vertical chem-mill fuselage skin cracks at certain butt joints; and an instance of cracking that occurred in all those three structural elements on one airplane. This AD requires repetitive inspections for any cracking of stringer splices and butt straps, and related corrective and investigative actions if necessary. We are issuing this AD to detect and correct cracking in the three structural elements, which could result in the airplane not being able to sustain limit load requirements and possibly result in uncontrolled decompression.

We are adopting a new airworthiness directive (AD) for Eurocopter Model EC225LP and AS332L1 helicopters with emergency floatation gear. The AD requires, before the next overwater flight, inspecting the strap installation on the hinged rods of the emergency flotation gear on both rear cradles for correct installation. If a strap is installed under the hinged rod median plate rather than over it, reinstalling the strap is required. The AD is prompted by incorrect routing of the straps on the hinged rods of the emergency flotation gear rear cradles. The actions are intended to detect incorrect strap installation and prevent failure of the rods or straps upon deployment of the emergency flotation gear, incorrect float position, and subsequent capsizing of the helicopter.