Airworthiness Directives; Boeing Model 747-100, 747-200, 747-300, and 747SR Series Airplanes Powered by General Electric CF6-45/50 or Pratt & Whitney JT9D-70 Series Engines

[Federal Register Volume 67, Number 4 (Monday, January 7, 2002)]
[Rules and Regulations]
[Pages 651-653]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-87]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-124-AD; Amendment 39-12578; AD 2001-26-12]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, 747-200, 747-300, 
and 747SR Series Airplanes Powered by General Electric CF6-45/50 or 
Pratt & Whitney JT9D-70 Series Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747-100, 747-200, 747-300, and 
747SR series airplanes powered by General Electric CF6-45/50 or Pratt & 
Whitney JT9D-70 series engines, that currently requires a detailed 
visual inspection of the outboard diagonal brace for heat damage and 
cracking; and follow-on repetitive inspections and corrective actions, 
if necessary. This amendment requires accomplishment of the previously 
optional replacement of any existing sealant with heat-resistant 
sealant as terminating action for the repetitive inspections required 
by this AD. This amendment is prompted by reports of heat damage to the 
forward end of the diagonal brace after accomplishment of a previous 
strut and wing modification. The actions specified by this AD are 
intended to prevent heat damage to the diagonal brace, which could 
cause cracking, fracture, and possible loss of the diagonal brace load 
path and consequent separation of the strut and engine from the 
airplane.

DATES: Effective February 11, 2002.
    The incorporation by reference of Boeing Alert Service Bulletin 
747-54A2208, dated March 29, 2001, was approved previously by the 
Director of the Federal Register as of June 27, 2001 (66 FR 31527, June 
12, 2001).

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

FOR FURTHER INFORMATION CONTACT: Tamara Anderson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2771; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 2001-12-05, 
amendment 39-12260 (66 FR 31527, June 12, 2001), which is applicable to 
certain Boeing Model 747-100, 747-200, 747-300, and 747SR series 
airplanes powered by General Electric CF6-45/50 or Pratt & Whitney 
JT9D-70 series engines, was published in the Federal Register on 
September 4, 2001 (66 FR 46241). The action proposed to continue to 
require a detailed visual inspection of the outboard diagonal brace for 
heat damage and cracking; and follow-on repetitive inspections and 
corrective actions, if necessary. The action also proposed to require 
accomplishment of the previously optional terminating replacement of 
any existing sealant with heat-resistant sealant as terminating action 
for the repetitive inspections.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Change to Final Rule

    Since the issuance of the proposal, the FAA has approved two 
alternative methods of compliance for AD 2001-12-05. A new paragraph 
(d)(2) has been added to this final rule to include those approvals.

Conclusion

    After careful review of the available data, the FAA has determined 
that air

[[Page 652]]

safety and the public interest require the adoption of the rule with 
the change previously described. The FAA has determined that this 
change will neither increase the economic burden on any operator nor 
increase the scope of the AD.

Cost Impact

    There are approximately 145 Model 747 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 39 
airplanes of U.S. registry will be affected by this AD.
    The repetitive inspections that are currently required by AD 2001-
12-05 take approximately 1 work hour per airplane to accomplish, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the currently required actions is estimated to be $2,340 
per airplane, per inspection cycle.
    The terminating action that is required by this AD action will take 
approximately 2 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$100 per airplane. Based on these figures, the cost impact of the 
requirements of this AD is estimated to be $8,580, or $220 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 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

    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]

    2. Section 39.13 is amended by removing amendment 39-12260 (66 FR 
31527, June 12, 2001), and by adding a new airworthiness directive 
(AD), amendment 39-12578, to read as follows:

2001-26-12  Boeing: Amendment 39-12578. Docket 2001-NM-124-AD. 
Supersedes AD 2001-12-05, Amendment 39-12260.

    Applicability: Model 747-100, 747-200, 747-300, and 747SR series 
airplanes; certificated in any category; powered by General Electric 
CF6-45/50 series engines, or Pratt & Whitney JT9D-70 series engines.

    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 (d)(1) 
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 heat damage to the diagonal brace, which could cause 
cracking or fracture of the diagonal brace, and possible loss of the 
diagonal brace load path and consequent separation of the strut and 
engine from the airplane, accomplish the following:

Restatement of Certain Requirements of AD 2000-12-05:

Verification

    (a) Within 90 days after June 27, 2001 (the effective date of AD 
2001-12-05, amendment 39-12260), do the actions required by 
paragraph (a)(1) or (a)(2) of this AD, as applicable.
    (1) If an operator's maintenance records verify that, during the 
accomplishment of AD 95-13-07, amendment 39-9287, the seal backup 
plates were restored and BMS 5-63 high-temperature sealant was used 
in that restoration, no further action is required by this AD.
    (2) If an operator's maintenance records do not verify that the 
actions specified in paragraph (a)(1) of this AD were accomplished, 
do the actions required by paragraph (b) of this AD.

Inspections and Corrective Actions

    (b) Within 90 days after June 27, 2001, do the inspections and 
applicable corrective actions specified by paragraphs (b)(1) and 
(b)(2) of this AD per the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-54A2208, dated March 29, 2001. 
Thereafter, repeat the inspections at intervals not to exceed 6 
months, until accomplishment of paragraph (c) of this AD.

Outboard Strut Diagonal Brace

    (1) Do a detailed visual inspection of the forward 20 inches of 
the outboard strut diagonal brace, including all areas of the 
forward clevis lugs and brace body, for signs of heat damage or 
cracks, per Part 1 of the Accomplishment Instructions of the service 
bulletin.
    (i) If no sign of heat damage or cracking is found, repeat the 
detailed visual inspection at intervals not to exceed 6 months, per 
the service bulletin, until accomplishment of paragraph (c) of this 
AD.
    (ii) If any primer discoloration is found, before further 
flight, do a non-destructive test (NDT) inspection of the area to 
determine if the diagonal brace has heat damage per Part 1 of the 
Accomplishment Instructions of the service bulletin.
    (A) If no heat damage is found during the NDT inspection, and no 
cracking is found during the detailed visual inspection, repeat the 
detailed visual inspection specified by paragraph (b)(1) of this AD 
at intervals not to exceed 6 months.
    (B) If any heat damage is found during the NDT inspection, or 
any cracking is found during the detailed visual inspection, before 
further flight, do the actions specified in paragraph (c)(2) of this 
AD. Thereafter, repeat the detailed visual inspection specified by 
paragraph (b)(1) of this AD at intervals not to exceed 6 months.

Firewall Openings of the Strut Aft Bulkhead

    (2) Do a detailed visual inspection of the firewall openings of 
the strut aft bulkhead to verify installation of seal backup plates 
and condition of the sealant application per Part 1 of the 
Accomplishment Instructions of the service bulletin.
    (i) If no discrepancy (including damaged or missing seal backup 
plates, or damaged or missing sealant) is found, repeat the detailed

[[Page 653]]

visual inspection specified by paragraph (b)(1) of this AD at 
intervals not to exceed 6 months.
    (ii) If the seal backup plates are not installed, before further 
flight, install the seal backup plates and apply heat-resistant 
sealant, BMS 5-63, per Part 2 of the Accomplishment Instructions of 
the service bulletin. Accomplishment of this action terminates the 
repetitive inspections required by this AD.
    (iii) If the seal backup plates are installed, but the sealant 
application is damaged or missing, before further flight, remove any 
existing sealant and apply heat-resistant sealant, BMS 5-63, per 
Part 3 of the Accomplishment Instructions of the service bulletin. 
Accomplishment of this action terminates the repetitive inspections 
required by this AD.

    Note 2: Because it is difficult to distinguish between BMS 5-95 
and BMS 5-63 sealants, removal and replacement of the existing 
sealant is required to ensure that the correct heat-resistant 
sealant, BMS 5-63, is used.

New Requirements of This AD

Terminating Action and Corrective Action

    (c) Within 18 months after the effective date of this AD: Do the 
action specified by paragraph (c)(1), (c)(2), or (c)(3) of this AD, 
as applicable. Accomplishment of the applicable action constitutes 
terminating action for the repetitive inspections required by this 
AD.
    (1) Following the inspections required by paragraphs (b)(1) and 
(b)(2) of this AD, if no cracking or heat damage is found during 
those inspections, and the seal backup plates are installed, before 
further flight, remove any existing sealant and apply heat-resistant 
sealant BMS 5-63, per Part 3 of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-54A2208, dated March 29, 2001.
    (2) If any sign of heat damage or cracking is found during the 
inspections required by paragraph (b) of this AD, before further 
flight, do the actions specified by either paragraph (c)(2)(i) or 
(c)(2)(ii) of this AD.
    (i) Replace the diagonal brace per Part 4 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-54A2208, dated 
March 29, 2001.
    (ii) Repair per 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 by the Manager, Seattle ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD.
    (3) If the seal back-up plates are not installed, before further 
flight, install the seal backup plates and apply heat-resistant 
sealant BMS 5-63, per Part 2 of the Accomplishment Instructions of 
the service bulletin.

Alternative Methods of Compliance

    (d)(1) 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.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 2001-12-05, amendment 39-12260, are approved as 
alternative methods of compliance with this AD.

    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

    (e) 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

    (f) Except as provided by paragraphs (a) and (c)(2)(ii) of this 
AD, the actions shall be done in accordance with Boeing Alert 
Service Bulletin 747-54A2208, dated March 29, 2001. The 
incorporation by reference of Boeing Alert Service Bulletin 747-
54A2208, dated March 29, 2001, was approved previously by the 
Director of the Federal Register as of June 27, 2001 (66 FR 31527, 
June 12, 2001). 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, Washington; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

Effective Date

    (g) This amendment becomes effective on February 11, 2002.

    Issued in Renton, Washington, on December 20, 2001.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-87 Filed 1-4-02; 8:45 am]
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