Federal Aviation Administration (FAA), Department of Transportation (DOT).
Notice of proposed rulemaking (NPRM).
The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 727 airplanes. This proposed AD would require doing an initial detailed inspection for cracks in the aft pressure bulkhead web; repairing any discrepancy; and doing repetitive detailed inspections, and doing related investigative actions, if necessary. This proposed AD results from reports of cracking in the aft pressure bulkhead web. We are proposing this AD to detect and correct a cracked pressure bulkhead web, which could result in rapid decompression of the airplane.
We must receive comments on this proposed AD by August 9, 2007.
Use one of the following addresses to submit comments on this proposed AD.
- DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
- Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
- Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
- Fax: (202) 493-2251.
- Hand Delivery: Room W12-140 on the ground floor of the West Building, 1200 New Jersey, Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this proposed AD.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6577; fax (425) 917-6590.End Further Info End Preamble Start Supplemental Information
We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2007-28378; Directorate Identifier 2007-NM-089-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.
Examining the Docket
You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone (800) 647-5527) is located on the ground level of the West Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.
We have received a report of a 6.8-inch crack oriented horizontally in the aft pressure bulkhead web located at station 1183 at water line 210 from right buttock line (RBL) 50.7 to RBL 57.5. We also have received a report of a 14.5-inch crack in the same bay between left buttock line (LBL) 46 to LBL 63. These events occurred on Boeing Model 727 airplanes. The cracks were attributed to fatigue of the pressure bulkhead web due to cabin pressurization cycles. Analysis by Boeing revealed multiple crack origins along the length of the web, which propagated through the web thickness. A cracked pressure bulkhead web, if not corrected, could result in rapid decompression of the airplane.
Relevant Service Information
We have reviewed Boeing Special Attention Service Bulletin 727-53-0230, dated January 8, 2007. The service information describes the following procedures:
- Doing an initial detailed inspection for cracks in the aft pressure bulkhead web;
- Doing repetitive detailed inspections if necessary; and
- Repairing any crack, doing related investigative actions if necessary, and contacting Boeing for certain repairs. The related investigative actions include a high frequency eddy current inspection and a detailed inspection to make sure that structure common to the Start Printed Page 34647repair installation is crack free and that no disbonding or corrosion is present.
The compliance time for the initial detailed inspection is before the accumulation of 40,000 total flight cycles, or within 3,500 flight cycles after the date of the service bulletin, whichever occurs later. The repeat interval is 12,000 flight cycles.
Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the Service Information.”
Differences Between the Proposed AD and the Service Information
The service information specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:
- Using a method that we approve; or
- Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.
Costs of Compliance
There are about 842 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 459 airplanes of U.S. registry. The proposed detailed inspection would take about 1 work hour per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $36,720, or $80 per airplane.
Authority for This Rulemaking
Title 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.
We 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 is likely to exist or develop on products identified in this rulemaking action.
We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.
For the reasons discussed above, I certify that the proposed regulation:
1. Is not a “significant regulatory action” under Executive Order 12866;
2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
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.
We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.Start List of Subjects
List of Subjects in 14 CFR Part 39End List of Subjects
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2007-28378; Directorate Identifier 2007-NM-089-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by August 9, 2007.
(c) This AD applies to all Boeing Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F series airplanes, certificated in any category.
(d) This AD results from reports of cracking in the aft pressure bulkhead web. We are issuing this AD to detect and correct a cracked pressure bulkhead web, which could result in rapid decompression of the airplane.
(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Inspection(s) and Corrective Actions
(f) Do an initial detailed inspection for cracks in the aft pressure bulkhead web in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 727-53-0230, dated January 8, 2007; except as provided by note (a) in Table 1 of paragraph 1.E., “Compliance,” of the service bulletin. Do the inspection at the compliance time identified in paragraph 1.E., “Compliance,” of the service bulletin; except as provided by paragraph (g) of this AD.
(1) If no crack is found, repeat the detailed inspection at the repeat interval identified in paragraph 1.E., “Compliance,” of the service bulletin, except as provided by note (a) in Table 1 of paragraph 1.E., “Compliance,” of the service bulletin.
(2) If any crack is found, before further flight, repair the crack and do the related investigative actions, in accordance with the Accomplishment Instructions of the service bulletin. If any crack, disbonding, or corrosion is found during related investigative actions, before further flight, repair the discrepancy using a method approved in accordance with the procedures specified in paragraph (h) of this AD.
(g) Where Boeing Special Attention Service Bulletin 727-53-0230, dated January 8, 2007, specifies a compliance time after the date of the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.
Alternative Methods of Compliance (AMOCs)
(h)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.
(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.Start Printed Page 34648
(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.
Issued in Renton, Washington, on June 18, 2007.
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. E7-12220 Filed 6-22-07; 8:45 am]
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