Federal Aviation Administration April 24, 2012 – Federal Register Recent Federal Regulation Documents

We propose to adopt a new airworthiness directive (AD) for certain Empresa Brasileria de Aeron[aacute]utica S.A. (EMBRAER) Model EMB-505 airplanes. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as an inadequate amount of drain holes in the primary control surfaces (rudder, elevator, and aileron) and their tab surfaces may allow water to accumulate in the control surfaces. This condition could cause unbalanced flight control surfaces and reduced flutter margins, which could result in loss of control of the airplane. We are issuing this proposed AD to require actions to address the unsafe condition on these products.

This rule establishes, amends, suspends, or revokes Standard Instrument Approach Procedures (SIAPs) and associated Takeoff Minimums and Obstacle Departure Procedures for operations at certain airports. These regulatory actions are needed because of the adoption of new or revised criteria, or because of changes occurring in the National Airspace System, such as the commissioning of new navigational facilities, adding new obstacles, or changing air traffic requirements. These changes are designed to provide safe and efficient use of the navigable airspace and to promote safe flight operations under instrument flight rules at the affected airports.

This rule establishes, amends, suspends, or revokes Standard Instrument Approach Procedures (SIAPs) and associated Takeoff Minimums and Obstacle Departure Procedures for operations at certain airports. These regulatory actions are needed because of the adoption of new or revised criteria, or because of changes occurring in the National Airspace System, such as the commissioning of new navigational facilities, adding new obstacles, or changing air traffic requirements. These changes are designed to provide safe and efficient use of the navigable airspace and to promote safe flight operations under instrument flight rules at the affected airports.

We are adopting a new airworthiness directive (AD) for certain Learjet Inc. Model 60 airplanes. This AD was prompted by two incidents of swapped fire extinguishing wires. This AD requires inspecting the electrical leads routed to the fire extinguishing containers for proper identification and missing labels, and to ensure the electrical leads are connected to the correct squibs; and corrective actions if necessary. We are issuing this AD to prevent the extinguishing agent of the fire extinguishing container from being delivered to the wrong engine in the event of an engine fire, and a consequent uncontrolled fire.

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes. This AD was prompted by reports of two failures of the single-tabbed bracket on the rudder. This AD requires replacing certain single-tabbed bonding brackets in the airplane empennage with two-tabbed bonding brackets. This AD also requires, for certain airplanes, installing new bonding jumpers, and measuring the resistance of the modified installation to verify resistance is within specified limits. We are issuing this AD to prevent failure of the bonding jumper bracket, which could result in loss of lightning protection ground path, which could lead to increased lightning-induced currents and subsequent damage to composite structures, hydraulic tubes, and actuator control electronics. In the event of a lightning strike, loss of lightning ground protection could result in the loss of control of the airplane.

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes. This AD was prompted by reports of cracks found in the Web pockets of the wing center section (WCS) spanwise beams. This AD requires repetitive detailed inspections and high frequency eddy current inspections for cracks of the WCS spanwise beams, and repair if necessary. We are issuing this AD to detect and correct cracking in the WCS spanwise beams, which could result in reduced structural integrity of the wings.

We are adopting a new airworthiness directive (AD) for all Learjet Inc., Model 45 airplanes. This AD was prompted by changes to the Airworthiness Limitations Section (ALS) of the maintenance manual, which adds life-limits, revises life-limits, or adds inspections not previously identified. This AD requires revising the maintenance program to include new or more restrictive life-limits and inspections. We are issuing this AD to limit exposure of flight critical components to corrosion, cracking, or failure due to life-limits, which if not corrected, could result in loss of roll control, fatigue cracking, or loss of structural components.

We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702), CL-600-2D15 (Regional Jet Series 705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. This AD was prompted by reports of the air driven generator (ADG) failing to power essential buses during functional tests, due to the low threshold setting of the circuit protection on the ADG's generator control unit (GCU) preventing the ADG from supplying power to the essential buses. This AD requires installing a new or serviceable ADG GCU. We are issuing this AD to prevent loss of power from the ADG to the essential buses which, in the event of an emergency, could prevent continued safe flight.