[Federal Register Volume 62, Number 208 (Tuesday, October 28, 1997)]
[Rules and Regulations]
[Pages 55732-55736]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-28347]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-229-AD; Amendment 39-10179; AD 97-22-07]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing Model 737 series airplanes, that
currently requires repetitive inspections to detect cracking of the
lower skin at the lower row of fasteners in the lap joints of the
fuselage, and repair of any cracking detected. This amendment requires
that the inspections be accomplished at more frequent intervals. This
amendment also adds a requirement for modification of the fuselage lap
joints at certain locations, which constitutes terminating action for
repetitive inspections of modified areas. This amendment is prompted by
reports of numerous fatigue cracks in the lower skin of the fuselage
lap joints at the lower row of fasteners. The actions specified in this
AD are intended to prevent such fatigue cracking, which could result in
sudden decompression of the airplane.
DATES: Effective November 12, 1997.
The incorporation by reference of certain publications, as listed
in the regulations, is approved by the Director of the Federal Register
as of November 12, 1997.
The incorporation by reference of Boeing Alert Service Bulletin
737-53A1177, dated November 8, 1994, as listed in the regulations, was
approved previously by the Director of the Federal Register as of
December 27, 1994 (59 FR 63716, December 9, 1994).
Comments for inclusion in the Rules Docket must be received on or
before December 29, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-229-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
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 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.
FOR FURTHER INFORMATION CONTACT: Gregory L. Schneider or Nenita K.
Odesa, Aerospace Engineers, Airframe Branch, ANM-120S, FAA, Transport
Airplane Directorate, Seattle Aircraft Certification Office (ACO), 1601
Lind Avenue, SW., Renton, Washington; telephone (425) 227-2028 or (425)
227-2557; fax (425) 227-1181.
[[Page 55733]]
SUPPLEMENTARY INFORMATION: On April 28, 1988, a Boeing Model 737 series
airplane was involved in an accident in which a 15-foot long section of
fuselage structure peeled open during flight. In light of this, the FAA
initiated an Aging Fleet Program. The objective of that program is to
identify and implement procedures to ensure the continuing structural
airworthiness of aging transport category airplanes.
As part of the Aging Fleet Program, the airplane manufacturer
conducted cyclic pressure (fatigue) tests to evaluate the performance
of the various fuselage skin panel lap joint configurations. The
fuselage skin panel joint consists of two adjacent panels that overlap
each other longitudinally and are joined together by three rows of
fasteners at the overlap (hence, lap joint). Cracks in the upper skin
of the lap joint led to the structural failure that occurred in the
1988 accident discussed previously. These ``first generation'' lap
joints, installed on early Model 737 series airplanes having line
numbers 1-291, were modified by replacing the countersunk fasteners in
the upper fastener row of the lap joint with protruding head fasteners
to correct and prevent cracking in the upper skin of the lap joint. No
cracking has been detected to date in the lower fastener row of these
(modified)``first generation'' lap joints.
In 1994, tests were conducted on ``second generation'' lap joints;
test results revealed cracks in the lower skin of this lap joint. The
airplane manufacturer determined that these cracks were caused by
increased stresses in this area due to the increased bending stresses
associated with the installation of a doubler on the upper skin. This
doubler was installed on ``second generation'' lap joints as an
improvement to the lap joint to prevent cracks in the upper skin. This
lap joint configuration, which incorporates the additional doubler, was
installed on Model 737 series airplanes having line numbers 292 through
2565.
In light of results of these tests, the manufacturer inspected the
lap joints of five aging airplanes and detected a total of 273 fatigue
cracks. The use of eddy current inspection techniques were required as
the cracks in the lower skin are not detectable visually due to the
positioning of the lower skin between the upper skin and the
circumferential tear strap. Many of these cracks were found to have
occurred simultaneously at adjacent fastener hole locations in the
lower skin of the fuselage lap joint.
This type of cracking of the lap joint is known as multiple site
damage (MSD). MSD is characterized by the simultaneous presence of
fatigue cracks in the same structural element (such as the lower skin
panel of the lap joint). Coalescence of cracks at adjacent fastener
holes in the lower skin can lead to sudden fracture and failure of the
lap joint, which could result in rapid decompression of the airplane.
Due to the reduction in the residual strength of a lap joint in the
presence of MSD. This reduction of the structural integrity of the
fuselage may occur at loads significantly below those that would be
expected for structure having a single large crack. The accident
discussed previously has demonstrated dramatically that small cracks
acting together can have a significant effect on the residual strength
of the aircraft structure.
Issuance of Previous Rule
On December 2, 1994, the FAA issued AD 94-25-05, amendment 39-9089
(59 FR 63716, December 9, 1994), applicable to certain Boeing Model 737
series airplanes, to require repetitive eddy current inspections to
detect cracking of the lower skin at the lower row of fasteners in the
lap joints of the fuselage between body stations 259.50 and 1016, and
repair of any cracking detected. That AD was prompted by reports of
fatigue cracking occurring simultaneously at adjacent fastener hole
locations in the lower skin of the fuselage lap joint. The actions
required by AD 94-25-05 are intended to prevent sudden decompression of
the airplane due to undetected cracking of the fuselage skin.
Actions Since Issuance of Previous Rule
Since the issuance of AD 94-25-05, the FAA has received additional
reports of fatigue cracking in the lower skin of the lap joints of the
fuselage on airplanes previously inspected in accordance with that AD.
The FAA received reports of numerous cracks on a number of airplanes
that had accumulated between 52,000 and 78,000 total flight cycles and
that had been inspected using low frequency eddy current (LFEC)
inspection techniques. The majority of these cracks occurred at left
and right stringers 4, 10, and 14.
The FAA also received recent reports indicating that extensive
cracking was found on three airplanes on which high frequency eddy
current (HFEC) inspections and modification of the lap joints had been
accomplished in accordance with Revision 1 of Boeing Alert Service
Bulletin 737-53A1177. Approximately eight months had elapsed since the
initial LFEC inspections required by AD 94-25-05 had been accomplished.
These airplanes had accumulated between 76,000 and 84,400 total flight
cycles. The total number of cracks reported was between 246 and 360 on
these three airplanes, and the majority of these cracks occurred at
left and right stringers 4, 10, and 14. On one of these airplanes,
cracking was found along a 111-inch section of stringer 4L at every
fastener hole in the lower row of fasteners in the lower skin that had
not been repaired during the previous LFEC inspection (82% of the total
fastener holes).
In the preamble to AD 94-25-05, the FAA specified that the actions
required by that AD were considered ``interim action'' and that the
manufacturer was developing a modification to positively address the
unsafe condition. The FAA indicated that it may consider further
rulemaking action once the modification was developed, approved, and
available. The manufacturer now has developed such a modification, and
the FAA has determined that further rulemaking action is indeed
necessary; this AD follows from that determination.
Explanation of Relevant Service Information
Since the issuance of AD 94-25-05, the FAA has reviewed and
approved Boeing Alert Service Bulletin 737-53A1177, Revision 1, dated
September 19, 1996; Revision 2, dated July 24, 1997; and Revision 3,
dated September 18, 1997; which describe procedures for inspections
similar to those specified in the original issue of the alert service
bulletin. (The original issue of the alert service bulletin was cited
in AD 94-25-05 as the appropriate source of service information).
Revision 1 of the alert service bulletin describes procedures for
modification of the lap joints at the lower row of fasteners in the
lower skin of the fuselage [reference Part III (``Preventive Change'')
of the Accomplishment Instructions of the alert service bulletin].
The relevant changes in Revision 2 of the alert service bulletin
include procedures for more frequent repetitive inspections of the
lower skin at the lower row of fasteners in the lap joints of the
fuselage.
For certain lap joint locations on Model 737-200 series airplanes
only, Revision 2 of the alert service bulletin also describes
procedures for an option to the modification (``Preventive Change'')
described in Revision 1 of the alert service bulletin. This option
[reference Part IV (``Lap Joint Repair'') of the Accomplishment
Instructions of the alert service bulletin] involves installing a lap
joint repair on the entire length of the skin panel at certain lap
joint locations.
[[Page 55734]]
Revision 3 of the alert service bulletin is essentially the same as
Revision 2; however, Revision 3 corrects a particular fastener size
specified in Part IV of the Accomplishment Instructions of the alert
service bulletin.
Accomplishment of the modification eliminates the need for the
repetitive inspections only of those areas that have been modified.
Accomplishment of the actions specified in the alert service bulletin
is intended to adequately address the identified unsafe condition.
FAA's Determinations
Based on reports of numerous cracks detected on airplanes inspected
previously, the FAA finds that, for certain airplanes, the repetitive
LFEC inspections required currently by AD 94-25-05 must be accomplished
at more frequent intervals to detect cracks that, in the presence of
MSD, could propagate to the point of structural failure of the lap
joints and result in rapid decompression of the airplane.
Based upon reports of extensive MSD found in the lower skin of the
lap joints located at stringers 4, 10, and 14, there may be a
significant reduction in the residual strength of these lap joints.
Because of this reduction in strength, in combination with the
possibility that cracks may go undetected due to human factors, the FAA
finds that the reduced inspection interval provided by this AD may not
be adequate to detect cracks which could propagate to the point of
structural failure. As a result, for airplanes that have accumulated
70,000 or more total flight cycles, the FAA has concluded that
modifications of the lap joints at stringers 4, 10, and 14 (as required
by this AD) on which the most severe cracking has been detected, must
be required on an emergency basis.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of this same type design, this AD
supersedes AD 94-25-05 to continue to require repetitive inspections to
detect cracking of the lower skin at the lower row of fasteners in the
lap joints of the fuselage, and repair of any cracking detected. This
AD requires that the inspections be accomplished at more frequent
intervals.
This AD also requires modification of the fuselage lap joints at
certain locations. Accomplishment of the modification constitutes
terminating action for the repetitive inspections only of those areas
that have been modified in accordance with this AD.
The inspections and modification are required to be accomplished in
accordance with the alert service bulletin described previously.
Explanation of Compliance Time for Initial Inspection
Operators should note that, for certain airplanes, the compliance
time for accomplishment of the initial inspection required by this AD
is approximately 120 days. That number of days is usually sufficient to
allow for prior notice to the public and a brief comment period before
adoption of a final rule. In this AD, however, that compliance time was
selected because of:
The large number of aircraft affected by the AD;
The large number of work hours required to accomplish the
inspection; and
The availability of an adequate number of maintenance
facilities able to accommodate scheduling the fleet for inspection.
A shorter compliance time might have resulted in the unnecessary
removal of airplanes from service pending scheduling. Nevertheless, the
FAA has determined that immediate adoption is necessary in this case
because of the importance of initiating the required inspections and
modification as soon as possible.
Differences Between the AD and the Relevant Service Bulletins
Operators should note that, for airplanes that have accumulated
between 60,000 and 65,000 total flight cycles, the alert service
bulletin specifies a repetitive inspection of 3,500 flight cycles until
the airplane has accumulated 65,000 total flight cycles. However, for
that group of airplanes, this AD requires that repetitive inspections
be accomplished at intervals not to exceed 1,200 flight cycles. The FAA
has determined that, because of the safety implications and
consequences of multiple site damage associated with fatigue cracking
of the fuselage skin, it is necessary to require earlier repetitive
inspections to ensure the continued operational safety of the fleet.
For Boeing Model 737-200 series airplanes only, Part IV of the
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1177, Revision 3, dated September 18, 1997, recommends installation
of a support cradle at station 540. However, this installation is not
intended to support the weight of the airplane. Therefore, this AD does
not require installation of this support cradle. In addition, to
clarify the reference in the alert service bulletin for supporting the
airplane in the jig position, paragraph (g)(2) of this AD explicitly
requires that, prior to conducting the repair of the lap joint, the
airplane be supported in the jig position, including support (removal)
of the engine weight. This action is required to be accomplished in
accordance with Boeing Document D6-15565, ``737 Structural Repair
Manual (SRM),'' Chapter 51, Subject 51-50-1, Revision 70, dated July 5,
1997.
Subsequent Rulemaking
The FAA may consider separate rulemaking action for airplanes that
have accumulated more than 70,000 total flight cycles to require
modification of the lap joints at the remaining locations specified in
Part III (``Preventive Change'') of the Accomplishment Instructions of
the alert service bulletin.
In addition, for airplanes that have accumulated less than 70,000
total flight cycles, the FAA may consider requiring accomplishment of
this modification at all locations specified in the alert service
bulletin.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments submitted will be
available, both before and after the closing date for comments, in the
rules docket for examination by
[[Page 55735]]
interested persons. A report that summarizes each FAA-public contact
concerned with the substance of this AD will be filed in the rules
docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-NM-229-AD.'' The postcard will be date stamped and
returned to the commenter.
Regulatory Impact
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the rules docket.
A copy of it, if filed, 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 39-9089 (59 FR
63716, December 9, 1994), and by adding a new airworthiness directive
(AD), amendment 39-10179, to read as follows:
97-22-07 Boeing: Amendment 39-10179. Docket 97-NM-229-AD.
Supersedes AD 94-25-05, Amendment 39-9089.
Applicability: Model Boeing 737 series airplanes having line
numbers 292 through 2565 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
otherwise 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 (i) 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 sudden decompression of the airplane, accomplish the
following:
(a) Perform a low frequency eddy current inspection to detect
cracking of the lower skin at the lower row of fasteners in the lap
joints of the fuselage at the time specified in paragraph (b) or (c)
of this AD, as applicable, in accordance with Part I
(``Inspection'') of the Accomplishment Instructions of Boeing Alert
Service Bulletin 737-53A1177, dated November 8, 1994; Revision 1,
dated September 19, 1996; Revision 2, dated July 24, 1997; or
Revision 3, dated September 18, 1997.
(b) For airplanes that have accumulated 70,000 total flight
cycles or more as of the effective date of this AD: Perform the
inspection required by paragraph (a) of this AD at the later of the
times specified in paragraphs (b)(1) and (b)(2) of this AD.
(1) Within 100 flight cycles after the effective date of this
AD.
(2) Within 300 flight cycles after the last inspection
accomplished in accordance with AD 94-25-05, amendment 39-9089.
(c) For airplanes that have accumulated less than 70,000 total
flight cycles as of the effective date of this AD: Perform the
inspection required by paragraph (a) of this AD at the later of the
times specified in paragraphs (c)(1) and (c)(2) of this AD.
(1) Prior to the accumulation of 60,000 total flight cycles.
(2) At the earliest of the times specified in paragraph
(c)(2)(i), (c)(2)(ii), and (c)(2)(iii) of this AD.
(i) Within 3,500 flight cycles after the last inspection
accomplished in accordance with AD 94-25-05, amendment 39-9089.
(ii) Within 1,200 flight cycles after the effective date of this
AD.
(iii) Prior to the accumulation of 70,300 total flight cycles.
(d) If any cracking is detected during the inspection required
by paragraph (a) of this AD, prior to further flight, repair it in
accordance with Part II (``Crack Repair'') of the Accomplishment
Instructions of Boeing Alert Service Bulletin 737-53A1177, dated
November 8, 1994; Revision 1, dated September 19, 1996; Revision 2,
dated July 24, 1997; or Revision 3, dated September 18, 1997.
(e) Repeat the inspection required by paragraph (a) of this AD
at the time specified in paragraph (e)(1) or (e)(2) of this AD, as
applicable, until the modification required by paragraph (f) or (g)
of this AD, as applicable, is accomplished.
(1) If the airplane had accumulated less than 70,000 total
flight cycles at the time of the immediately preceding inspection,
perform the next inspection within 1,200 flight cycles or prior to
the accumulation of 70,300 total flight cycles, whichever occurs
first.
(2) If the airplane had accumulated 70,000 or more total flight
cycles at the time of the immediately preceding inspection, perform
the next inspection within 300 flight cycles.
(f) Except as provided by paragraph (g) of this AD, modify the
fuselage lap joints at the lower row of fasteners at stringer
locations right/left stringer 4 between body station (BS) 360 and BS
1016; and right/left stringers 10 and 14 between BS 360 and BS 540,
and between BS 727 and BS 1016; in accordance with Part III
(``Preventive Change'') of the Accomplishment Instructions of Boeing
Alert Service Bulletin 737-53A1177, Revision 1, dated September 19,
1996; Revision 2, dated July 24, 1997; or Revision 3, dated
September 18, 1997; at the time specified in paragraph (h) of this
AD. Accomplishment of this modification constitutes terminating
action for the repetitive inspections only for the areas that have
been modified in accordance with this AD.
(g) For Boeing Model 737-200 series airplanes only:
(1) Except as provided in paragraphs (g)(2) and (g)(3) of this
AD, in lieu of accomplishing the modification (``Preventive
Change'') specified in paragraph (f) of this AD, installation of the
lap joint repair in accordance with Part IV (``Lap Joint Repair'')
of the Accomplishment Instructions of Boeing Alert Service Bulletin
737-53A1177, Revision 3, dated September 18, 1997, at the locations
specified in Part IV of the alert service bulletin, may be
accomplished. Accomplishment of the repair constitutes terminating
action for the repetitive inspections only for the areas that have
been modified in accordance with this AD.
(2) Prior to conducting the repair, support the airplane in the
jig position, including support (removal) of the engine weight, in
accordance with Boeing Document D6-15565, ``737 Structural Repair
Manual (SRM),'' Chapter 51, Subject 51-50-1, Revision 70, dated July
5, 1997.
Note 2: Chapter 51, Subject 51-50-1 of the referenced SRM
references Subjects 51-50-2, 51-50-3, and 51-60 of the referenced
SRM as additional sources of service information.
(3) Notwithstanding the Accomplishment Instructions of Boeing
Alert Service Bulletin
[[Page 55736]]
737-53A1177, Revision 3, dated September 18, 1997, the repair
described in paragraph (g)(1) of this AD may be accomplished without
installing a support cradle at station 540.
(h) Accomplish the modification required by paragraph (f) or (g)
of this AD, as applicable, at the latest of the times specified in
paragraphs (h)(1), (h)(2), and (h)(3) of this AD.
(1) Prior to the accumulation of 70,000 total flight cycles.
(2) Within 600 flight cycles after the effective date of this
AD.
(3) Within 80 days after the effective date of this AD.
(i) 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(j) 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.
(k) The actions shall be done in accordance with Boeing Alert
Service Bulletin 737-53A1177, dated November 8, 1994; Boeing Alert
Service Bulletin 737-53A1177, Revision 1, dated September 19, 1996;
Boeing Alert Service Bulletin 737-53A1177, Revision 2, dated July
24, 1997; Boeing Alert Service Bulletin 737-53A1177, Revision 3,
dated September 18, 1997; and Boeing Document D6-15565, ``737
Structural Repair Manual (SRM),'' Chapter 51, Subject 51-50-1,
Revision 70, dated July 5, 1997, which contains the following list
of effective pages (NOTE: The issue date and revision level of the
SRM are indicated only on the Title Page; no other page of the
document contains this information.):
------------------------------------------------------------------------
Revision level shown Date shown on
Page No. on page page
------------------------------------------------------------------------
Title page....................... 70.................. July 5, 1997.
1................................ Not shown........... Feb. 5, 1989.
2, 3, 11, 12..................... Not shown........... Aug. 5, 1988.
4................................ Not shown........... Feb. 1, 1978.
5, 6, 8-10....................... Not shown........... Aug. 1, 1968.
7................................ Not shown........... Feb. 1, 1975.
------------------------------------------------------------------------
(1) The incorporation by reference of Boeing Alert Service
Bulletin 737-53A1177, Revision 1, dated September 19, 1996; Boeing
Alert Service Bulletin 737-53A1177, Revision 2, dated July 24, 1997;
Boeing Alert Service Bulletin 737-53A1177, Revision 3, dated
September 18, 1997; and Boeing Document D6-15565, ``737 Structural
Repair Manual (SRM),'' Chapter 51, Subject 51-50-1, Revision 70,
dated July 5, 1997; is approved by the Director of the Federal
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
(2) The incorporation by reference of Boeing Alert Service
Bulletin 737-53A1177, dated November 8, 1994, was approved
previously by the Director of the Federal Register as of December
27, 1994 (59 FR 63716, December 9, 1994).
(3) 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.
(l) This amendment becomes effective on November 12, 1997.
Issued in Renton, Washington, on October 21, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-28347 Filed 10-27-97; 8:45 am]
BILLING CODE 4910-13-U
