AD 2003-11-25

[Federal Register Volume 68, Number 112 (Wednesday, June 11, 2003)]
[Rules and Regulations]
[Pages 34787-34790]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 03-14274]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-394-AD; Amendment 39-13185; AD 2003-11-25]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747SR, and 747SP 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing transport category airplanes listed above. 
This AD requires an initial inspection to identify all H-11 steel bolts 
on the outer chord of the body station (BS) 2360 aft pressure bulkhead 
between stringers 12L and 12R, follow-on repetitive inspections to 
identify all remaining H-11 steel bolts on the entire outer chord of 
the BS 2360 aft pressure bulkhead, and follow-on and corrective actions 
if necessary. This AD also requires eventual replacement of all H-11 
steel bolts with Inconel bolts. This action is necessary to prevent 
broken bolts, which could result in progressive failure of the 
remaining bolts and consequent structural damage, rapid 
depressurization, and loss of control of the airplane. This action is 
intended to address the identified unsafe condition.

DATES: Effective July 16, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 16, 2003.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of

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the Federal Register, 800 North Capitol Street, NW., Suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Rick Kawaguchi, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6434; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 747 series 
airplanes was published in the Federal Register on September 25, 2002 
(67 FR 60189). That action proposed to require an initial inspection to 
identify all H-11 steel bolts on the outer chord of the body station 
(BS) 2360 aft pressure bulkhead between stringers 12L and 12R, follow-
on repetitive inspections to identify all remaining H-11 steel bolts on 
the entire outer chord of the BS 2360 aft pressure bulkhead, and 
follow-on and corrective actions if necessary. That action also 
proposed to require eventual replacement of all H-11 steel bolts with 
Inconel bolts.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. The FAA has given due consideration to 
the comments received.

Request to Revise Statement of Unsafe Condition

    One commenter requests that the FAA revise the unsafe condition in 
the proposed AD, which states that the consequences of not finding 
broken H-11 steel bolts is progressive failure of the remaining bolts 
and consequent structural damage and rapid depressurization of the 
airplane. The commenter notes that, while these are effects of 
progressive bolt failure, it is more significant that such failure 
could result in loss of control of the airplane. We concur and have 
revised the statement of unsafe condition throughout this final rule.

Request to Clarify Subject of Repetitive Inspections

    One commenter requests that we revise paragraph (c) of the proposed 
AD to clarify that the repeat inspections in that paragraph apply only 
to the remaining H-11 steel bolts (that is, the H-11 steel bolts that 
have not been replaced with Inconel bolts). We concur that the 
repetitive ultrasonic inspections and torque checks for cracked or 
broken bolts are necessary only for the remaining H-11 steel bolts. We 
have clarified paragraph (c) of this final rule accordingly.

Request to Revise Instructions in Paragraph (d) of Proposed AD

    One commenter requests that we revise the instructions in paragraph 
(d) of the proposed AD to remove the instruction to coat the Inconel 
bolt with corrosion-inhibiting compound after installation. The 
commenter states that the instructions for applying corrosion 
protection on the replacement Inconel bolt that are stated in paragraph 
(d) of the proposed AD are incomplete and suggests alternative 
instructions. The commenter recommends that paragraph (d) refer to 
Figure 4 of the service bulletin.
    We do not agree that any change is necessary. Paragraph (d) of this 
AD requires replacing all subject H-11 steel bolts per Boeing Alert 
Service Bulletin 747-53A2474, dated October 25, 2001. When we refer to 
a service bulletin in this way in an AD, operators are required to 
follow all procedures in the service bulletin, including the 
instructions for corrosion prevention that are specified in Figure 4 of 
the service bulletin. (We note that the Accomplishment Instructions of 
the service bulletin refer to Figure 4 of the service bulletin for 
replacement procedures.) No change to the final rule is needed in this 
regard.

Request to Require Inspection or Replacement of Adjacent H-11 Steel 
Bolts

    One commenter requests that we consider requiring operators to 
inspect or replace an H-11 steel bolt (including reworking the bolt 
hole) found on either side of a cracked H-11 steel bolt during the 
initial inspection. The commenter states that such a requirement should 
not add significant downtime and will better ensure safety.
    We do not agree that any change is necessary. This AD requires 
inspecting all H-11 steel bolts in the subject area, which would 
include H-11 bolts adjacent to cracked or broken bolts. While an 
operator has the option of immediately replacing any H-11 steel bolt 
that is adjacent to a cracked or broken bolt, we find that performing 
repetitive inspections of remaining H-11 steel bolts will provide an 
acceptable level of safety until all H-11 steel bolts are replaced as 
required by paragraph (d) of this AD. (Such replacement is required 
within 6 years after the effective date of the AD.) No change to the 
final rule is needed in this regard.

Clarification of Applicability

    We have revised the applicability statement of this AD to clarify 
that Boeing Model 747-400, -400D, and -400F series airplanes are not 
affected by this AD. The airplanes with line numbers 1 through 644 
inclusive are Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-
200F, 747-200C, 747-300, 747SR, and 747SP series airplanes.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 487 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 165 airplanes of U.S. registry 
will be affected by this AD.
    It will take approximately 9 work hours per airplane to accomplish 
the required initial inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the initial 
inspection on U.S. operators is estimated to be $89,100, or $540 per 
airplane.
    It will take approximately 35 work hours per airplane to accomplish 
the required follow-on inspection to identify all remaining H-11 steel 
bolts on the entire outer chord, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the follow-on 
inspection on U.S. operators is estimated to be $346,500, or $2,100 per 
airplane, per inspection cycle.
    Should an operator be required to replace the H-11 steel bolts, it 
will take approximately 108 work hours per airplane to accomplish the 
replacement, at an average labor rate of $60 per work hour. Required 
parts will cost approximately $3,233 per airplane. Based on these 
figures, the cost impact is estimated to be $9,713 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These

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figures typically do not include incidental costs, such as the time 
required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2003-11-25 Boeing: Amendment 39-13185. Docket 2001-NM-394-AD.

    Applicability: Model 747-100, 747-100B, 747-100B SUD, 747-200B, 
747-200F, 747-200C, 747-300, 747SR, and 747SP series airplanes; line 
numbers 1 through 644 inclusive; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (g) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent broken H-11 steel bolts, which could result in 
progressive failure of the remaining bolts and consequent structural 
damage, rapid depressurization, and loss of control of the airplane, 
accomplish the following:

Initial Inspection

    (a) Within 18 months after the effective date of this AD: Do a 
detailed inspection to identify all H-11 steel bolts on the outer 
chord of the body station (BS) 2360 aft pressure bulkhead between 
stringers 12L and 12R. Do the inspection by checking the bolt part 
number stamped on the bolt head, or verifying the bolt is steel by 
using a magnet, per Boeing Alert Service Bulletin 747-53A2474, dated 
October 25, 2001. If no H-11 steel bolt is found, no further action 
is required by this paragraph. If any H-11 steel bolt is found, do 
the requirements specified in paragraph (c) of this AD.

    Note 2: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

Follow-On Inspections/Corrective Actions

    (b) Within 18 months after doing the inspection required by 
paragraph (a) of this AD, or within 18 months after the effective 
date of this AD, whichever is later: Do a detailed inspection to 
identify all remaining H-11 steel bolts on the entire outer chord of 
the BS 2360 aft pressure bulkhead, per Boeing Alert Service Bulletin 
747-53A2474, dated October 25, 2001. If no H-11 steel bolt is found, 
no further action is required by this paragraph. If any H-11 steel 
bolt is found, do the requirements specified in paragraph (c) of 
this AD.
    (c) For any H-11 steel bolt found during any inspection required 
by paragraph (a) or (b) of this AD: Before further flight, do either 
an ultrasonic inspection or a torque check for cracked or broken 
bolts, or replace the H-11 steel bolt with an Inconel bolt per 
Boeing Alert Service Bulletin 747-53A2474, dated October 25, 2001. 
Replace any cracked or broken bolt with an Inconel bolt before 
further flight per the service bulletin. Then repeat the inspection 
of the remaining H-11 steel bolts at intervals not to exceed 18 
months until the terminating action required by paragraph (d) of 
this AD is done.

Terminating Action

    (d) Within 6 years after the effective date of this AD: Replace 
all H-11 steel bolts on the entire outer chord of the BS 2360 aft 
pressure bulkhead with Inconel bolts (including visually inspecting 
the bolt hole for corrosion, oversizing the hole up to 1/32 inch to 
remove any corrosion, and, after installing an Inconel bolt, coating 
the bolt with corrosion inhibitor compound), per Boeing Alert 
Service Bulletin 747-53A2474, dated October 25, 2001. When this 
paragraph is done, the requirements of this AD are terminated.

Exceptions to Service Information

    (e) Where Boeing Alert Service Bulletin 747-53A2474, dated 
October 25, 2001, specifies to contact Boeing for appropriate 
action: Before further flight, repair in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA; or per data meeting the type certification basis of the 
airplane approved by a Boeing Company Designated Engineering 
Representative who has been authorized by the Manager, Seattle ACO, 
to make such findings. For a repair method to be approved, the 
approval must specifically reference this AD.

Spares

    (f) As of the effective date of this AD: No person shall install 
an H-11 steel bolt on the outer chord of the BS 2360 aft pressure 
bulkhead on any airplane.

Alternative Methods of Compliance

    (g) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (h) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Incorporation by Reference

    (i) Unless otherwise provided by this AD, the actions shall be 
done in accordance with Boeing Alert Service Bulletin 747-53A2474, 
dated October 25, 2001. This incorporation by reference was approved 
by the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Copies may be obtained from Boeing 
Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-
2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton,

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Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., Suite 700, Washington, DC.

Effective Date

    (j) This amendment becomes effective on July 16, 2003.


    Issued in Renton, Washington, on May 30, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-14274 Filed 6-10-03; 8:45 am]
BILLING CODE 4910-13-P