Federal Aviation Administration April 1, 2005 – Federal Register Recent Federal Regulation Documents

This document revises an earlier NPRM, applicable to all Boeing Model 737-100, -200, and -200C series airplanes. The original NPRM would have required repetitive inspections to detect discrepancies of certain fuselage skin panels located just aft of the wheel well, and repair if necessary. The original NPRM was prompted by reports of fatigue cracking of the skins and doublers located aft of the wing, between body station (BS) 727 and BS 1016, and between body stringers 14 and 25. This supplemental NPRM revises the original NPRM by adding requirements for certain airplanes, revising the compliance time for inspection of modified skin areas, and allowing alternative service information for certain actions. The actions specified by this new supplemental NPRM are intended to detect and correct fatigue cracking of the skin panels, which could cause rapid decompression of the airplane. This action is intended to address the identified unsafe condition.

The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 707, 720, and 720B series airplanes. This proposed AD would require revising the Limitations section of the airplane flight manual (AFM). The AFM revisions include instructions for monitoring the low pressure lights for the center tank fuel pumps, and a statement prohibiting the resetting of a tripped circuit breaker for a fuel pump in any tank. This proposed AD is prompted by the results of fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent dry operation of the fuel pumps in the center fuel tank, which could result in high temperatures or sparks inside the fuel tank, ignition of fuel vapors, and consequent fire or explosion. We are also issuing this AD to prohibit the resetting of a tripped circuit breaker for a fuel pump in any tank, which could allow an electrical fault to override the protective features of the circuit breaker, and result in sparks inside the fuel tank, ignition of fuel vapors, and consequent fire or explosion.

The FAA proposes to adopt a new airworthiness directive (AD) for certain Extra Flugzeugproduktions- und Vertriebs- GmbH (EXTRA) Models EA- 300, EA-300S, EA-300L, and EA-300/200 airplanes. This proposed AD would require you to seal with firewall sealant the gaps between the bottom fuselage cover (belly fairing) and the firewall and repeat the sealing procedure whenever you install the bottom fuselage cover (belly fairing). This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. We are issuing this proposed AD to prevent fuel from flowing behind the firewall in the case of a fuel leak. This could result in an in-flight fire, which could cause loss of the airplane and crew.