Airworthiness Directives; Boeing Model 757-200 Series Airplanes

[Federal Register Volume 69, Number 119 (Tuesday, June 22, 2004)]
[Rules and Regulations]
[Pages 34557-34559]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-13699]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2003-16646; Directorate Docket No. 2003-NM-177-AD; 
Amendment 39-13678; AD 2004-12-17]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200 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 Model 757-200 series airplanes, that 
requires repetitive inspections of the intercostals that back up the 
door stops and hinges at door 2 left and door 2 right for cracks, and 
corrective action, if necessary. This amendment also provides for an 
optional terminating action for the repetitive inspections. This action 
is necessary to prevent fatigue cracks from propagating in the 
intercostals, which could lead to the loss of a door in flight and 
subsequent rapid decompression. This action is intended to address the 
identified unsafe condition.

DATES: Effective July 27, 2004.
    The incorporation by reference of a certain publication listed in 
the regulations is approved by the Director of the Federal Register as 
of July 27, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, 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 National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

FOR FURTHER INFORMATION CONTACT: Dennis Stremick, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6450, 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 757-200 
series airplanes was published in the Federal Register on December 11, 
2003 (68 FR 69053). That action proposed to require repetitive 
inspections of the intercostals that back up the door stops and hinges 
at door 2 left and door 2 right for cracks, and corrective action, if 
necessary. That action also proposed to provide for an optional 
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 single comment received.

Request To Increase Repetitive Inspection Interval

    One commenter requests that the repetitive inspection interval 
specified in paragraph (c) of the proposed AD be increased from 3,000 
flight cycles to 9,000 flight cycles. The commenter states that its in-
service experiences demonstrate that a 9,000 flight cycle inspection 
interval is adequate to ensure that cracks are detected in a timely 
manner prior to becoming critical. The commenter justifies its 
recommendation based on its initial visual inspections conducted on 14 
airplanes having around 15,000 total flight cycles, during which no 
cracking was found. Subsequent repeat inspections conducted on those 
airplanes at about 8,000 flight cycles later (at about 23,000 total 
flight cycles) found cracking. On average, the commenter found cracks 
on two out of six intercostals per side, per airplane, and the cracks 
were generally less than 1.5 inches. The commenter also states that the 
worst-case safety concern is the loss of cabin pressure, which is a 
lesser concern than loss of airplane. The commenter notes that access 
is more difficult than stated in the proposed AD because a lavatory and 
coat closet must be removed to gain access to the subject area.
    The FAA does not agree to increase the repetitive inspection 
interval required by paragraph (c) of the final rule from 3,000 flight 
cycles to 9,000 flight cycles. The commenter did not provide enough 
data to support an inspection interval of 9,000 flight cycles. The 
commenter's statement that it found multiple cracks occurring within an 
8,000 flight cycle inspection interval indicates that an appropriate 
inspection interval would be less than 8,000 flight cycles. In 
addition, based on the commenter's findings that an average of two out 
of six intercostals were cracked per door, it is more than likely that 
half of the intercostals would be cracked on some airplanes within the 
commenter's proposed 9,000 flight cycle interval. While a loss of cabin 
pressure may occur prior to losing a door, the detection of multiple 
cracked intercostals within the commenter's proposed inspection 
interval increases the possibility of losing a door. We have determined 
that the inspection interval of 3,000 flight cycles required by 
paragraph (c) of the final rule will ensure an acceptable level of 
safety. In developing an appropriate inspection interval for this AD, 
we considered the safety issues resulting from the loss of a door in 
flight and possible subsequent rapid decompression, as well as the 
recommendations of the manufacturer and the effectiveness of the 
inspection procedure. Also, the final rule provides optional 
terminating actions, as stated in paragraphs (g) and (h) of the final 
rule, for the repetitive inspections required by paragraph (c) of the 
final

[[Page 34558]]

rule. No change is made to the final rule in this regard. However, 
according to the provisions of paragraph (i) of the final rule, we may 
approve requests to adjust the inspection interval if the request 
includes data that prove that the new inspection interval would provide 
an acceptable level of safety.

Conclusion

    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    There are approximately 95 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 55 airplanes of U.S. registry 
will be affected by this AD.
    We estimate that it will take approximately 8 work hours per 
airplane to accomplish the required inspection, and that the average 
labor rate is $65 per work hour. Based on these figures, the cost 
impact of the required inspection on U.S. operators is estimated to be 
$28,600, or $520 per airplane, per inspection cycle.
    The cost impact figure discussed above is 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.
    The optional preventative modification terminating action, if done, 
will take approximately 50 work hours per airplane at an average labor 
rate of $65 per work hour. Based on these figures, we estimate the cost 
of this optional terminating action to be $3,250 per airplane.
    Parts for the optional replacement terminating action will cost 
approximately $692 for each Top Kit-Door Stop 1 Intercostal (L/H or R/
H) and $4,581 for each Top Kit-Intercostal Replacement (L/H or R/H).

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

0
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:

2004-12-17 Boeing: Amendment 39-13678. Docket FAA-2003-16646. 
Directorate Docket No. 2003-NM-177-AD.

    Applicability: Model 757-200 series airplanes, line numbers 1 
through 95 inclusive; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracks from propagating in the intercostals, 
which could lead to the loss of a door in flight and subsequent 
rapid decompression, accomplish the following:

Service Bulletin References

    (a) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 757-53-0086, dated March 14, 2002.

Initial Inspection

    (b) Prior to the accumulation of 12,000 total flight cycles, or 
within 3,000 flight cycles after the effective date of this AD, 
whichever occurs later: Perform a detailed inspection for cracks of 
the intercostals that back up the door stops and hinges at door 2 
left and door 2 right, per Part I of the service bulletin.

No Crack Findings: Repetitive Inspections

    (c) If no crack is found during the inspection required by 
paragraph (b) of this AD, before further flight, do a dye penetrant 
or eddy current inspection for cracks of the intercostals that back 
up the door stops and hinges at door 2 left and door 2 right, per 
Part I of the service bulletin. Repeat thereafter at intervals not 
to exceed 3,000 flight cycles, until the preventative modification 
specified in paragraph (g) of this AD or the replacement specified 
in paragraph (h) of this AD has been accomplished.

Crack Findings: Modification/Replacement

    (d) If, during the inspections required by paragraph (b) and/or 
(c) of this AD, any intercostal for door stop 1, 4, 5, 6, upper 
hinge, or lower hinge has cracks, but not beyond the aft edge of the 
bend relief radius: Before further flight, do the preventative 
modification specified in paragraph (g) of this AD or the 
replacement specified in paragraph (h) of this AD.
    (e) If, during the inspections required by paragraph (b) and/or 
(c) of this AD, any intercostal for door stop 2 or 3 has cracks: 
Before further flight, do the replacement specified in paragraph (h) 
of this AD.
    (f) If, during the inspections required by paragraph (b) and/or 
(c) of this AD, any intercostal has cracks that extend beyond the 
aft edge of the bend relief radius: Before further flight, do the 
replacement specified in paragraph (h) of this AD.

Terminating Actions

    (g) Do the preventative modification on the intercostal per Part 
II of the service bulletin. Accomplishment of the preventative 
modification on an intercostal per Part II of the service bulletin 
constitutes terminating action for the repetitive inspection 
requirements of this AD for the modified intercostal only.
    (h) Replace the intercostal with a new improved intercostal per 
Part III of the service bulletin. Accomplishment of the replacement 
of an intercostal with a new, improved intercostal per Part III of 
the service bulletin constitutes terminating action for the 
repetitive inspection requirements of this AD for the replaced 
intercostal only.

Alternative Methods of Compliance

    (i) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

Incorporation by Reference

    (j) The actions shall be done in accordance with Boeing Special 
Attention Service Bulletin 757-53-0086, dated March 14, 2002. 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 Airplanes, P.O. 
Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at 
the FAA, Transport Airplane Directorate, 1601 Lind

[[Page 34559]]

Avenue, SW., Renton, Washington; or at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Effective Date

    (k) This amendment becomes effective on July 27, 2004.

    Issued in Renton, Washington, on June 9, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-13699 Filed 6-21-04; 8:45 am]
BILLING CODE 4910-13-P

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