Examining the Docket \n\n\tYou may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section. \n\nDiscussion \n\n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to all Boeing Model 727, 727C, 727-100, and 727-100C series airplanes. That NPRM was published in the Federal Register on December 15, 2005 (70 FR 74237). That NPRM proposed to require repetitive inspections for cracks in the body skin and bear strap at the upper and lower hinge cutouts of the mid-cabin galley doorway, along the upper fastener row of the stringer 14R lap splice, and in the doorstop fitting adjacent to the upper hinge cutout; and corrective action if necessary. That NPRM also proposed to provide for optional terminating action for certain inspections. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments received from one commenter, the airplane manufacturer. \n\nRequest To Clarify Description of the Unsafe Condition \n\n\tBoeing asks that the description of the unsafe conditions, as specified in paragraph (d) of the NPRM, be changed for clarification, to add the following: "There are also reports of cracking on airplanes modified in production to resist such cracking.'' Boeing states that "The modification installed in production was to enlarge the cutout radius. This did not prevent cracking, but rather resisted and delayed cracking to a later time.'' \n\n\tWe infer that Boeing is asking for a change to the Summary section, as well as the second sentence in paragraph (d) of this AD. These paragraphs describe what prompted the AD. In the Discussion section of the NPRM we did note that modifications done in production did not prevent cracking. Therefore, we agree to clarify paragraph (d) and the Summary section as follows: "There are also reports of cracking on airplanes previously modified in production to resist such cracking.'' \n\nRequest To Change the Discussion Section \n\n\tBoeing asks that the eighth and ninth sentences in the Discussion section of the NPRM be changed. Those sentences are as follows: "Some of the cracks were found on airplanes that were modified in service by increasing the radius of the corners of the body skin at the hinge cutouts, and installing doublers at the high cutouts; and airplanes on which the equivalent modification was done in production. These modifications did not prevent the cracking.'' Boeing asks that those sentences be changed to the following: "Some of the cracks found on airplanes that were modified in production by increasing the radius of the cutout corners of the body skin hinge cutouts (sic). This modification did not prevent the cracking.'' Boeing states that this would correctly reflect that production modifications included only increasing the skin cutout radius and did not include installing skin doublers in the hinge areas. Boeing adds that production records indicate that no doublers were installed in production. \n\n\tWe acknowledge Boeing's concern and agree with the comment. No cracks have been reported yet on airplanes that were modified in service using Boeing Service Bulletin 727-53-0054, which increases the radius of the cutout corners of the body skin hinge cutouts, and adds skin doublers in the hinge areas. However, the "Discussion'' section is included in an NPRM as background information on the unsafe condition to provide adequate information to the public during the comment period. The "Discussion'' section is not included in the final rule. We have made no change to the AD in this regard. \n\nRequest To Change the Other Relevant Rulemaking Section \n\n\tBoeing asks that the fifth sentence in the Other Relevant Rulemaking section of the NPRM be changed. That sentence specifies "One of the structural modifications in that AD is of the body skin of the mid-galley door hinge cutouts done in accordance with Boeing Service Bulletin 727-53-0054, Revision 1, dated November 16, 1989.'' Boeing asks that the sentence be changed to the following, "One of the structural modifications in that AD is of the body skin of the mid- galley door hinge cutouts, done in accordance with Boeing Service Bulletin 727-53-0054, initial release, dated June 26, 1968, with additional instructions shown in Boeing Document D6-54860, Rev C, page 3.2.1 for Boeing Service Bulletin 727-53-0054.'' Boeing states that the airplane effectivity specified in Revision 1 increased by three airplanes. \n\n\tWe acknowledge Boeing's concern and agree with the comment. In addition, we note that Boeing Document D6-54860, Rev C, specifies the airplane effectivity per the latest revision of the service bulletin, which is Service Bulletin 727-53-0054, Revision 1, which did include three additional airplanes. However, the "Other Relevant Rulemaking'' section of the NPRM is not included in the final rule. We have made no change to the AD in this regard. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCosts of Compliance \n\n\tThere are about 232 airplanes of the affected design in the worldwide fleet. This AD affects about 123 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this AD, per inspection cycle. \n\n\tEstimated Costs \n\n\nAirplane group \nWorkhours \nAverage hourly labor rate \nCost per airplane \nGroup 1, Configuration 1 \n10 \n$65\n$650 \nGroup 1, Configuration 2 \n10 \n65 \n650 \nGroup 1, Configuration 3 \n9 \n65 \n585 \nGroup 2 \n9 \n65 \n585 \n\n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority. \n\n\tWe are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, "General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that islikely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the National Government and the States, or on the distribution of power and responsibilities among the various levels of government. \n\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(1) Is not a "significant regulatory action'' under Executive Order 12866; \n\n\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\n\t(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. \n\n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):