[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
[[Page 38125]]
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
