[Federal Register Volume 63, Number 135 (Wednesday, July 15, 1998)]
[Proposed Rules]
[Pages 38123-38126]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-18775]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-227-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727-200 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Boeing Model 727-200 series 
airplanes. This proposal would require repetitive inspections to detect 
cracks in certain areas between the upper and lower sills of the number 
1 cargo door, and repair,

[[Page 38124]]

if necessary. This proposal is prompted by reports indicating that 
fatigue cracks were found in certain structures adjacent to the number 
1 cargo door cutout at the forward and aft doorway frames. The actions 
specified by the proposed AD are intended to detect and correct such 
fatigue cracking, which could result in rapid decompression of the 
fuselage and consequent reduced structural integrity of the airplane.

DATES: Comments must be received by August 31, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No.97-NM-227-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Walter Sippel, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2774; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-NM-227-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 97-NM-227-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that cracks were found in 
the structure adjacent to the number 1 cargo door cutout at the doorway 
frames at body station (BS) 560 and BS 620 on Boeing Model 727-200 
series airplanes. In one of these incidents, the aft frame web and 
frame inner chord of the number 1 cargo door cutout, which was 
previously repaired because of cracking, was found completely severed. 
In another incident, a crack was found in the aft doorway structure of 
the number 1 cargo door during pressure cycling of the fuselage of a 
Model 727-200 series airplane. The frame web and the frame inner and 
outer chords were severed and cracks were found in the bear strap and 
skin, which prevented pressurization of the airplane. The cracking has 
been attributed to fatigue, caused by pressurization cycles of the 
fuselage structure. Such fatigue cracking, if not corrected, could 
result in rapid decompression of the fuselage and consequent reduced 
structural integrity of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
727-53A0219, Revision 1, dated May 8, 1997, which describes the 
following procedures:
     Performing repetitive close visual inspections to detect 
cracks in the forward and aft frames, bear strap, and fuselage skin 
between the upper and lower sills of the number 1 cargo door at BS 560 
and BS 620;
     Performing repetitive high frequency eddy current 
inspections to detect cracks in the forward and aft frames, and bear 
strap between the upper and lower sills of the number 1 cargo door at 
BS 560 and BS 620; and
     Repairing any cracked forward or aft frame, bear strap, or 
fuselage skin.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the alert service bulletin described previously, except as discussed 
below.

Differences Between Proposed Rule and Relevant Alert Service 
Bulletin

    Operators should note that, although the referenced alert service 
bulletin specifies that the manufacturer may be contacted for 
disposition of certain conditions, this proposal would require the 
repair of those conditions to be accomplished in accordance with a 
method approved by the FAA. Likewise, operators also should note that, 
although the alert service bulletin defines the inspection intervals 
and methods for inspecting repairs that have been accomplished after 
contacting the manufacturer for repair information, this proposal would 
require the inspection methods and intervals to be accomplished in 
accordance with methods and intervals approved by the FAA.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Other Relevant Rulemaking

    The FAA has previously issued AD 98-11-03, amendment 39-10530 (63 
FR 27455, May 19, 1998), which addresses, in part, cracking of the 
number 1 cargo door cutout structure on certain Model 727 series 
airplanes. That AD requires that the FAA-approved maintenance or 
inspection program be revised to include inspections of Structural 
Significant Items, and repair of cracked structure. These actions are 
conducted as part of the Supplemental Structural Inspection Program. 
(Components of the number 1 cargo door cutout structure are identified 
as structural significant items.) This proposed AD would not affect the 
current requirements of AD 98-11-03.

Cost Impact

    There are approximately 1,100 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 770 airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 60 work

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hours per airplane to accomplish the proposed inspections, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the inspections proposed by this AD on U.S. operators is 
estimated to be $2,772,000, or $3,600 per airplane, per inspection 
cycle.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this 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) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

Boeing: Docket 97-NM-227-AD.

    Applicability: All Model 727-200 series airplanes, 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 (d) 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 detect and correct fatigue cracking between the upper and 
lower sills of the number 1 cargo door, which could result in rapid 
decompression of the fuselage and consequent reduced structural 
integrity of the airplane, accomplish the following:
    (a) Perform a close visual inspection or a high frequency eddy 
current (HFEC) inspection (as applicable) to detect cracks in the 
forward and aft frames (web, inner chord, and outer chord), bear 
strap, and fuselage skin between the upper and lower sills of the 
number 1 cargo door at BS 560 and BS 620; in accordance with Boeing 
Alert Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997; 
at the time specified in paragraph (a)(1), (a)(2), or (a)(3) of this 
AD, as applicable.
    (1) For airplanes on which the repair to the forward or aft 
frame (web, inner chord, or outer chord), bear strap, or fuselage 
skin specified in the alert service bulletin has not been 
accomplished: Inspect prior to the accumulation of 30,000 total 
flight cycles, or within 3,000 flight cycles after the effective 
date of this AD, whichever occurs later.
    (2) For airplanes on which the repair to the forward or aft 
frame (web, inner chord, or outer chord) specified in the alert 
service bulletin has been accomplished: Inspect within 3,000 flight 
cycles after the effective date of this AD.
    (3) For airplanes on which the repair to the bear strap, 
fuselage skin, or a combination of the frame web and chord (inner or 
outer) on either the forward or aft frame specified in the alert 
service bulletin has been accomplished: Inspect within 3,000 flight 
cycles after the effective date of this AD, in accordance with a 
method approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate.

    Note 2: Where there are differences between this AD and the 
referenced alert service bulletin, the AD prevails.
    Note 3: The inspections specified in paragraph (a)(3) of this AD 
are not defined in the alert service bulletin.

    (b) If no crack is detected during any inspection required by 
paragraph (a) of this AD, accomplish paragraph (b)(1) or (b)(2) of 
this AD, as applicable.
    (1) For airplanes identified in paragraphs (a)(1) and (a)(2) of 
this AD: Repeat the close visual and HFEC inspection required by 
paragraph (a) of this AD thereafter at the times specified in 
paragraphs (b)(1)(i) and (b)(1)(ii) of this AD.
    (i) Repeat the close visual inspection of the frame web at 
intervals not to exceed 3,000 flight cycles.
    (ii) Repeat the close visual and HFEC inspections (as 
applicable) of the frame web, frame inner and outer chords, bear 
strap, and fuselage skin thereafter at intervals not to exceed 
15,000 flight cycles.
    (2) For airplanes identified in paragraph (a)(3) of this AD: 
Repeat the inspections of the repaired bear strap, fuselage skin, or 
combination of a repaired frame web and chord (inner or outer) 
thereafter at intervals not to exceed those approved by the Manager, 
Seattle ACO.
    (c) If any crack is detected during any inspection required by 
paragraph (a) of this AD, prior to further flight, accomplish 
paragraph (c)(1) or (c)(2) of this AD, as applicable.
    (1) For any crack detected in the frame web, inner chord, or 
outer chord: Repair in accordance with Boeing Alert Service Bulletin 
727-53A0219, Revision 1, dated May 8, 1997. Prior to the 
accumulation of 3,000 flight cycles after accomplishment of the 
repair, accomplish the close visual and HFEC inspections specified 
in paragraph (a) of this AD. Repeat the close visual inspection of 
the frame web thereafter at intervals not to exceed 3,000 flight 
cycles. Repeat the close visual and HFEC inspections (as applicable) 
of the frame web, inner chord, and outer chord thereafter at 
intervals not to exceed 15,000 flight cycles.
    (2) For any crack detected in the fuselage skin, bear strap, or 
a combination of the frame web and chord (inner or outer): Repair 
and perform repetitive inspections in accordance with both a method 
and repetitive inspection interval approved by the Manager, Seattle 
ACO.

    Note 4: The repairs and inspections specified in paragraph 
(c)(2) of this AD are not defined in the alert service bulletin.

    (d) 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 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (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.


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    Issued in Renton, Washington, on July 8, 1998.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-18775 Filed 7-14-98; 8:45 am]
BILLING CODE 4910-13-P