[Federal Register Volume 72, Number 121 (Monday, June 25, 2007)]
[Proposed Rules]
[Pages 34646-34648]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-12220]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28378; Directorate Identifier 2007-NM-089-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: 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.

DATES: We must receive comments on this proposed AD by August 9, 2007.

ADDRESSES: 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.

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.

SUPPLEMENTARY INFORMATION:

Comments Invited

    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.

Discussion

    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

[[Page 34647]]

repair 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.

Regulatory Findings

    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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

    2. The Federal Aviation Administration (FAA) amends Sec.  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.

Affected ADs

    (b) None.

Applicability

    (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.

Unsafe Condition

    (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.

Compliance

    (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.

[[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.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-12220 Filed 6-22-07; 8:45 am]
BILLING CODE 4910-13-P