Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 757-200 series airplanes modified by particular STCs. The NPRM published in the Federal Register on June 5, 2015 (80 FR 32061) (''the NPRM''). The NPRM was prompted by reports of a main cargo door being blown past its full open position while on the ground during gusty wind conditions, which resulted in uncontrolled fall down to its closed position. The NPRM proposed to require installation of a new placard and bracket, replacement of an existing placard, and replacement of the main cargo door control panel. We are issuing this AD to prevent damage to the main cargo door, which could result in rapid decompression of the airplane, or injury to maintenance and ground crew during ground operations. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA's response to each comment. \n\nRequest To Revise Description of the Unsafe Condition \n\n\n\tPrecision Conversions, LLC requested that we revise the SUMMARY and Discussion sections of the NPRM and the unsafe condition section of the proposed AD. Precision Conversions, LLC stated that it was concerned by certain conclusions stated in the NPRM for which it does not believe there is a factual basis. Precision Conversions, LLC noted that the NPRM stated that wind damage to a cargo door could result in rapid decompression, leading to in-flight breakup. However, even without the accomplishment of Precision Conversions Service Bulletin PC-757-11- 0023, dated August 1, 2014, Precision Conversions, LLC stated that the suggested scenario would not occur. If, during ground operations, the main cargo door were to deflect beyond the fully open position enough to be of concern, its damaged operating system would prevent the cargo door from closing as usual, which would not go unnoticed by the crew, and the airplane would not be dispatched. Thus, a potential unsafe condition would occur only on the ground, not in the air. \n\tPrecision Conversions, LLC stated that a potential for an unsafe condition does arise from the possibility of ground crew operating the main cargo door outside of the wind limits published in the aircraft maintenance manual and operations manual supplements. Precision Conversions, LLC asserted that exceeding published limits could result in damage to the door operating system and loss of control of the door, creating an unsafe condition, but only during ground operations; thus, Precision Conversions, LLC believed that the proposed language regarding rapid decompression and in-flight breakup had no basis, given the relevant factual scenario, and should not be included in the final rule. Precision Conversions, LLC requested that we revise the unsafe condition to indicate that the NPRM will ''prevent winddamage to the main cargo door operating system and ensure its safe use during ground operations.'' \n\tWe partially agree with the request. We disagree that a damaged door will always be detected because of human factors. We agree, however, that rapid decompression might not necessarily lead to in- flight breakup, which would depend on the decompression. We have therefore revised the SUMMARY and Discussion sections of this final rule and paragraph (e), Unsafe Condition, of this AD to remove reference to in-flight breakup, and to include injury to maintenance and ground crew during ground operations. \n\nStatement Regarding Content of NPRM \n\n\n\tBoeing stated that the NPRM does not address or affect any Boeing designs; therefore, Boeing can neither review the data nor comment on the content of the NPRM. \n\nConclusion \n\n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this AD with the changes described previously and minor editorial changes. We have determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\tWe also determined that these changes will not increase the economic burden on any operator or increase the scope of this AD. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tWe reviewed Precision Conversions LLC Service Bulletin PC-757-11- 0023, dated August 1, 2014. The service information describes procedures for installing a new placard and bracket, replacement of an existing placard, and replacement of the main cargo door control panel. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 9 airplanes of U.S. registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tAction Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Installation...................... 6 work-hours x $85 per $0 * $510 $4,590 \n\thour = $510. ---------------------------------------------------------------------------------------------------------------- \n* According to the manufacturer, the kits will be provided at no charge to operators.\n\n\nAuthority for This Rulemaking \n\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\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 \n\n((Page 10074)) \n\nthat is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\n\tThis 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\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a ''significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\t(3) Will not affect intrastate aviation in Alaska, and \n\t(4) 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\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.