Federal Aviation Administration June 11, 2008 – Federal Register Recent Federal Regulation Documents

The FAA invites public comments about our intention to request the Office of Management and Budget's (OMB) approval of a new information collection. The Federal Register Notice with a 60-day comment period soliciting comments on the following collection of information was published on March 20, 2008, vol. 73, no. 55, page 15042. This project involves the random and representative sampling of Flight Attendants currently employed by U.S. air carriers.

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This AD requires various repetitive inspections to detect cracks along the chemically milled steps of the fuselage skin or missing or loose fasteners in the area of the preventative modification or repairs, replacement of the time-limited repair with the permanent repair if applicable, and applicable corrective actions if necessary, which would end certain repetitive inspections. This AD results from a fatigue test that revealed numerous cracks in the upper skin panel at the chemically milled step above the lap joint. We are issuing this AD to detect and correct such fatigue-related cracks, which could result in the crack tips continuing to turn and grow to the point where the skin bay flaps open, causing decompression of the airplane.

We are adopting a new airworthiness directive (AD) for the products listed above. This 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: * * * * * The assessment and lightning tests showed that certain fuel tube self-bonded couplings do not provide sufficient lightning current capability. The assessment also showed that single failure of the integral bonding wire of the self-bonded couplings could affect electrical bonding between the tubes. Insufficient electrical bonding between fuel tubes or insufficient current capability of fuel tube couplings, if not corrected, could result in arcing and potential ignition source[s] inside the fuel tank during lightning strikes and consequent fuel tank explosion. * * *

We are adopting a new airworthiness directive (AD) for certain Boeing Model 777 airplanes. This AD requires an inspection to determine the manufacturer and manufacture date of the oxygen masks in the center and outboard passenger service units, crew rests, and lavatory and flight attendant oxygen boxes, as applicable. This AD also requires related investigative/corrective actions if necessary. This AD results from a report that several passenger masks with broken in-line flow indicators were found following a mask deployment. We are issuing this AD to prevent the in-line flow indicators of the passenger oxygen masks from fracturing and separating, which could inhibit oxygen flow to the masks and consequently result in exposure of the passengers and cabin attendants to hypoxia following a depressurization event.

We are adopting a new airworthiness directive (AD) for certain Cessna Aircraft Company (Cessna) Model 525 airplanes. This AD requires you to inspect for missing firewall sealant between the aft firewall assembly and seal assembly; and, if you find that firewall sealant is missing, seal with firewall sealant between the aft firewall assembly and seal assembly. This AD results from a report that firewall sealant may not have been applied between the aft firewall assembly and seal assembly during manufacture of certain Model 525 airplanes. We are issuing this AD to detect and correct missing firewall sealant between the aft firewall assembly and seal assembly, which could result in failure of the fire extinguishing system to prevent the spread of fire through the firewall gap. This failure could lead to an uncontrolled fire.