[Federal Register Volume 67, Number 71 (Friday, April 12, 2002)]
[Rules and Regulations]
[Pages 17931-17934]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-8457]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-74-AD; Amendment 39-12705; AD 2002-07-11]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200 and -200C Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

[[Page 17932]]

applicable to certain Boeing Model 737-200 and -200C series airplanes, 
that requires repetitive inspections to find cracking of certain 
fuselage lap joint areas, and repair of any cracking found. This 
amendment also requires eventual modification of those areas, which 
constitutes terminating action for the repetitive inspections. This 
action is necessary to find and fix cracking of certain fuselage lap 
joint areas, which could result in rapid decompression of the airplane. 
This action is intended to address the identified unsafe condition.

DATES: Effective May 17, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 17, 2002.

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: Scott Fung, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-1221; 
fax (425) 227-1181.

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 737-200 and -
200C series airplanes was published in the Federal Register on July 12, 
2001 (66 FR 36520). That action proposed to require repetitive 
inspections to find cracking of certain fuselage lap joint areas, and 
repair of any cracking found. That action also proposed to require 
eventual modification of those areas, which would constitute 
terminating action for the repetitive inspections.

Comments

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

Change Paragraph (e)

    One commenter, the airplane manufacturer, asks that paragraph (e) 
of the proposed rule be changed to instruct operators to install the 
lap joint repair referenced in the proposed rule per Part 1.E.3. 
(``Compliance'') of the service bulletin. The commenter states that 
paragraph (e) instructs operators to install the lap joint repair on 
left and right stringer S-10 and S-14 lap joints per Part III (``Lap 
Joint Repair'') of the Accomplishment Instructions of the service 
bulletin. The commenter notes that Part III defines the instructions 
for the full lap joint cutout repair for the crown area lap joints, but 
the modification for the local areas of the S-10 and S-14 lap joints 
subject to this AD is done per Boeing 737 Structural Repair Manual 
(SRM), Section 53-30-3, Figure 44. The instructions for doing this 
modification per the SRM are provided in Part 1.E.3. (``Compliance'').
    The FAA agrees with the commenter. The reference to Part III (``Lap 
Joint Repair'') of the Accomplishment Instructions of the service 
bulletin required by paragraph (e) of the final rule is not an 
incorrect reference; however, that section does not specifically call 
out Section 53-30-3, Figure 44, of the Boeing 737 SRM. Therefore, we 
have changed paragraph (e) of the final rule to add doing the 
installation of the lap joint repair of the left and right stringer S-
10 and S-14 lap joints of the fuselage per Part III (``Lap Joint 
Repair'') of the Accomplishment Instructions of the service bulletin, 
or Part 1.E.3. (``Compliance'') of the service bulletin, as applicable.

Previous Revisions of Service Information

    One commenter asks that Boeing Service Bulletins 737-53A1177, 
Revision 4, dated September 2, 1999; and Revision 5, dated February 15, 
2001; be added as acceptable sources of service information for doing 
the terminating action specified in paragraph (e) of the proposed rule. 
We agree because the terminating action specified in those revisions is 
the same as the terminating action specified in the service information 
referenced in the final rule. We have added a Note 3 to this final rule 
(and reordered subsequent notes accordingly) to specify that 
accomplishment of the terminating action before the effective date of 
this AD according to those revisions is acceptable for compliance with 
paragraph (e) of this final rule.

Change Work Hours for Modification

    The same commenter notes that the Differences section of the 
proposed rule states that the proposed modifications would require 
taking the airplane out of service for at least 22 days. However, in 
the Cost Impact section of the proposed rule, work hours necessary for 
the modification are estimated at 16 hours. The commenter's estimate is 
14 hours for the modification, or approximately one day.
    The FAA infers that the commenter is asking that the work hours for 
the modification, as specified in the Cost Impact section of the final 
rule, be changed. We do not agree with the commenter's request. We note 
that the commenter inadvertently transposed the work hours specified 
for the modifications and the inspections. The actual work hour 
estimate for the modifications is 75 hours, and the estimate for the 
inspections is 16 hours. The number of work hours necessary to 
accomplish the required actions, restated below, is based on the 
information provided by the airplane manufacturer in its service 
bulletin. This number represents the time necessary to perform only the 
actions actually required by this AD--the ``direct'' costs. Because 
costs may vary significantly from operator to operator, they are almost 
impossible to calculate. No change to the final rule is necessary in 
this regard.

Change to Final Rule

    The compliance plan requirements specified in paragraph (d) of this 
final rule have been changed to exclude operators that have previously 
done the modification required by paragraph (e) of the final rule, and 
the requirement to provide dates and maintenance events (e.g., letter 
checks) has been changed to just estimated dates, for operators that 
have not yet done the required actions. Paragraphs (d) and (e) of the 
final rule have been changed accordingly.

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 159 Model 737-200 and -200C series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 55 airplanes of U.S. registry (over 10 years) will be 
affected by this AD.
    It will take approximately 16 work hours per airplane to accomplish 
the required inspections, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the inspections 
required by this AD on U.S.

[[Page 17933]]

operators is estimated to be $52,800, or $960 per airplane, per 
inspection cycle.
    It will take approximately 75 work hours per airplane to accomplish 
the required modifications, at an average labor rate of $60 per work 
hour. Required parts will cost approximately $1,500 per airplane. Based 
on these figures, the cost impact of the modifications required by this 
AD on U.S. operators is estimated to be $330,000, or $6,000 per 
airplane.
    The compliance plan that is required by this AD action will take 
approximately 24 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the compliance plan on U.S. operators is estimated to be 
$79,200, or $1,440 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 adding the following new 
airworthiness directive:

2002-07-11  Boeing: Amendment 39-12705. Docket 2000-NM-74-AD.

    Applicability: Model 737-200 and -200C airplanes having line 
numbers 1 through 291 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 (f) 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 find and fix cracking of certain fuselage lap joint areas, 
which could result in rapid decompression of the airplane, 
accomplish the following:

Repetitive Low Frequency Eddy Current (LFEC) Inspections

    (a) Do an LFEC inspection to find cracking of the left and right 
stringers S-10 and S-14 lap joints of the fuselage, located between 
body station (BS) 727 and BS 747, per Figures 7 and 8 of the 
Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, 
Revision 6, dated May 31, 2001; at the time specified in paragraph 
(a)(1) or (a)(2) of this AD, as applicable. Repeat the inspection 
after that at intervals not to exceed 1,200 flight cycles until 
accomplishment of the lap joint modification (repair) required by 
paragraph (e) of this AD.
    (1) For airplanes that have accumulated 70,000 or more total 
flight cycles as of the effective date of this AD: At the later of 
the times specified in paragraphs (a)(1)(i) and (a)(1)(ii) of this 
AD.
    (i) Before the accumulation of 71,200 total flight cycles.
    (ii) Within 300 flight cycles after the effective date of this 
AD.
    (2) For airplanes that have accumulated 45,000 or more total 
flight cycles, but less than 70,000 total flight cycles as of the 
effective date of this AD: At the later of the times specified in 
paragraphs (a)(2)(i) and (a)(2)(ii) of this AD.
    (i) Before the accumulation of 50,000 total flight cycles.
    (ii) Within 1,200 flight cycles after the effective date of this 
AD.

Crack Repair

    (b) Except as provided by paragraph (c) of this AD: If any 
cracking is found during any inspection required by this AD, before 
further flight, repair per Part II (``Crack Repair'') of the 
Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, 
Revision 6, dated May 31, 2001.
    (c) If any cracking is found during any inspection required by 
this AD, and Boeing Service Bulletin 737-53A1177, Revision 6, dated 
May 31, 2001, specifies to contact Boeing for repair instructions: 
Repair before further flight, 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 (DER) 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 approval letter must specifically 
reference this AD.

Compliance Plan

    (d) For airplanes on which the modification required by 
paragraph (e) of this AD has not been done as of the effective date 
of this AD: Within 3 months after the effective date of this AD, 
submit a plan to the FAA identifying a schedule for compliance with 
paragraph (e) of this AD. This schedule must include, for each of 
the operator's affected airplanes, the estimated dates when the 
required actions will be accomplished. For the purposes of this 
paragraph, ``FAA'' means the Principal Maintenance Inspector (PMI) 
for operators that are assigned a PMI, or the cognizant Flight 
Standards District Office for other operators. Information 
collection requirements contained in this regulation have been 
approved by the Office of Management and Budget (OMB) under the 
provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et 
seq.) and have been assigned OMB Control Number 2120-0056.

    Note 2: Operators are not required to submit revisions to the 
compliance plan required by paragraph (d) of this AD to the FAA.

Lap Joint Modification (Repair)

    (e) Except as provided by paragraph (d) of this AD, before the 
accumulation of 50,000 total flight cycles or within 5,000 flight 
cycles after the effective date of this AD, whichever comes later: 
Install the lap joint repair of the left and right stringer S-10 and 
S-14 lap joints of the fuselage, between body

[[Page 17934]]

station (BS) 727 and BS 747, per Part III (``Lap Joint Repair'') of 
the Accomplishment Instructions, or Part 1.E.3. ``Compliance,'' of 
Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001, 
as applicable. Installation of this repair ends the repetitive 
inspections of the repaired areas required by paragraph (a) of this 
AD.

    Note 3: Installation of the lap joint repair before the 
effective date of this AD per Boeing Service Bulletin 737-53A1177, 
Revision 4, dated September 2, 1999; or Revision 5, dated February 
15, 2001; is acceptable for compliance with paragraph (e) of this 
AD.

Alternative Methods of Compliance

    (f) 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 4: 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

    (g) 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

    (h) Except as provided by paragraphs (c) and (d) of this AD, the 
actions shall be done in accordance with Boeing Service Bulletin 
737-53A1177, Revision 6, dated May 31, 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, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (i) This amendment becomes effective on May 17, 2002.

    Issued in Renton, Washington, on April 2, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-8457 Filed 4-11-02; 8:45 am]
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