[Federal Register Volume 64, Number 233 (Monday, December 6, 1999)]
[Proposed Rules]
[Pages 68062-68065]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-31477]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-74-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 727-100, -100C, and -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 certain Boeing Model 727-100, -
100C, and -200 series airplanes. For certain airplanes, this proposal
would require a one-time inspection of certain fuselage circumferential
skin joints to determine the type of fasteners installed, and
replacement of any aluminum fasteners with steel fasteners, if
necessary; or modification of certain fuselage circumferential skin
joints; as applicable. For certain other airplanes, this proposal would
also require repetitive inspections to detect corrosion, sealant
deterioration, cracking, or disbonding; repair, if necessary; and
modification of certain fuselage circumferential skin joints. This
proposal is prompted by reports of corrosion between the body skins and
cold-bonded doublers at the fuselage circumferential skin joints. The
actions specified by the proposed AD are intended to prevent
delamination of the cold-bonded doublers, which could result in
corrosion of the body skins and doublers, and consequent reduced
structural capability of the fuselage circumferential skin joints.
DATES: Comments must be received by January 20, 2000.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-74-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: Walt 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 99-NM-74-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. 99-NM-74-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
In 1990, the FAA issued AD 90-06-09, amendment 39-6488 (55 FR 8370,
March 7, 1990), which required incorporation of certain structural
modifications on certain Boeing Model 727 series airplanes, in
accordance with Boeing Document No. D6-54860, Revision C, dated
December 11, 1989, ``Aging Airplane Service Bulletin Structural
Modification Program--Model 727.'' One of those modifications was
replacement of countersunk fasteners installed at cold-bonded doublers
of fuselage circumferential skin joints at body stations (BS) 259, 360,
441, 481, and 681 with oversize, protruding-head fasteners. That AD was
prompted in part by reports of corrosion between the body skins and
cold-bonded doublers at the fuselage circumferential skin joints.
Delamination of the cold-bonded doublers allows moisture to enter voids
caused by the bond separation, which could result in corrosion of the
body skins and doublers, and consequent reduced structural capability
of the fuselage circumferential skin joints.
Since the issuance of AD 90-06-09, the airplane manufacturer has
notified the FAA that the incorrect fastener type was used in the
modification of the fuselage circumferential skin joints required by
that AD. Aluminum fasteners were used for that modification; the
airplane manufacturer now knows that aluminum fasteners reduce the
structural capability of the fuselage circumferential skin joints.
In 1990, the FAA also issued AD 90-26-09, amendment 39-6835 (55 FR
51403, December 14, 1990), which required repetitive inspections of
certain fuselage circumferential skin joints, and repair, if necessary,
in accordance with Boeing Service Bulletin 727-53-0084, Revision 4,
dated August 2, 1990. The modification of the fuselage circumferential
skin joints required by AD 90-06-09 was considered terminating action
for certain repetitive inspections required by AD 90-26-09.
Since the issuance of AD 90-26-09, the airplane manufacturer has
notified the FAA that certain airplanes were inadvertently not included
in the effectivity listing in paragraph I.A.1. of Boeing Service
Bulletin 727-53-0084, Revision 4, although they were included in the
effectivity statement in the summary of the service bulletin. The FAA
has determined that operators of those airplanes may not realize that
those airplanes are subject to AD 90-26-09. In addition, the airplane
manufacturer has notified the FAA that
[[Page 68063]]
those same airplanes were also inadvertently not included in the
effectivity listing of Boeing Document No. D6-54860, Revision C, and
hence, were also omitted from the applicability of AD 90-06-09. Those
airplanes are subject to the same unsafe condition as the airplanes
that are included in the applicability statements of those two AD's.
Therefore, the FAA finds that additional rulemaking is necessary to
ensure that the unsafe condition is addressed on all affected
airplanes.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 727-53-
0084, Revision 4, dated August 2, 1990, which describes procedures for
repetitive inspections of the cold-bonded doublers of the fuselage
circumferential skin joints at BS 259, 360, 441, 481, and 681; and
repair, if necessary. The inspections include an external detailed
visual inspection to detect corrosion and sealant deterioration, a low
frequency eddy current (LFEC) inspection to detect corrosion, a high
frequency eddy current (HFEC) inspection to detect cracking, and an
internal detailed visual inspection to detect cracking, sealant
deterioration, or disbonding. The service bulletin also describes
procedures for modification of the cold-bonded doublers in those areas.
In addition, the service bulletin describes procedures for a one-time
inspection of the fuselage circumferential skin joints at BS 259, 360,
441, 481, and 681 to determine the type of fasteners installed, and
replacement of any aluminum fasteners with steel fasteners, if
necessary. Accomplishment of the actions specified in the service
bulletin is intended to adequately address the identified unsafe
condition.
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 service bulletin described previously, except as discussed below.
Differences Between Proposed Rule and Service Bulletin
Operators should note that, although the service bulletin specifies
that the manufacturer may be contacted for disposition of certain
repair conditions, this AD requires the repair of those conditions to
be accomplished in accordance with a method approved by the FAA, or in
accordance with data meeting the type certification basis of the
airplane approved by a Boeing Company Designated Engineering
Representative who has been authorized by the FAA to make such
findings.
Operators should also note that, for those airplanes on which
modification of cold-bonded doublers of certain fuselage
circumferential skin joints has already been accomplished, this AD
proposes only to mandate the one-time inspection of the joints to
determine the type of fastener installed, and replacement of any
aluminum fasteners with steel fasteners, if necessary; or modification
of certain fuselage circumferential skin joints; as applicable.
Operators should also note that this proposed AD would require the
repetitive inspections and modification of the cold-bonded doublers of
certain fuselage circumferential skin joints for only certain
airplanes. These airplanes were inadvertently omitted from the
applicability of AD 90-26-09.
The service bulletin recommends accomplishing the repetitive
internal visual inspections every 30 months if the repetitive HFEC
inspection is accomplished every 48 months, or accomplishing the
repetitive internal visual inspections every 48 months if the
repetitive HFEC inspection is accomplished every 15 months. In
developing an appropriate compliance time for this AD, the FAA
considered not only the manufacturer's recommendation, but the degree
of urgency associated with addressing the subject unsafe condition, the
average utilization of the affected fleet, and the time necessary to
perform the inspections. In light of all of these factors, the FAA
finds a 48-month compliance time for both the internal visual
inspection and the HFEC inspection to be warranted, in that it
represents an appropriate interval of time allowable for affected
airplanes to continue to operate without compromising safety. This
compliance time is consistent with that specified in AD 90-26-09.
Cost Impact
There are approximately 549 airplanes of the affected design in the
worldwide fleet. Based on a records review, the FAA estimates that only
374 of those airplanes are still in service. The FAA estimates that 280
airplanes of U.S. registry still in service would be affected by this
proposed AD.
The number of airplanes that would be subject to the proposed one-
time inspection to determine the type of fasteners installed is
unknown. For affected airplanes, it would take approximately 45 work
hours per airplane to accomplish the proposed one-time inspection, at
an average labor rate of $60 per work hour. Based on these figures, the
cost impact of this proposed inspection on U.S. operators is estimated
to be $2,700 per airplane.
The FAA estimates that 3 airplanes of U.S. registry would be
required to perform the external detailed visual inspection of certain
fuselage circumferential skin joints that is proposed in this AD
action. It would take approximately 8 work hours per airplane to
accomplish this proposed inspection, at an average labor rate of $60
per work hour. Based on these figures, the cost impact of this proposed
inspection on U.S. operators is estimated to be $1,440, or $480 per
airplane, per inspection cycle.
The FAA estimates that 3 airplanes of U.S. registry would be
required to perform the internal detailed visual inspection of certain
fuselage circumferential skin joints that is proposed in this AD
action. It would take approximately 12 work hours per airplane to
accomplish this proposed inspection, at an average labor rate of $60
per work hour. Based on these figures, the cost impact of this proposed
inspection on U.S. operators is estimated to be $2,160, or $720 per
airplane, per inspection cycle.
The FAA estimates that 3 airplanes of U.S. registry would be
required to perform the LFEC inspection of certain fuselage
circumferential skin joints that is proposed in this AD action. It
would take approximately 100 work hours per airplane to accomplish this
proposed inspection, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of this proposed inspection on
U.S. operators is estimated to be $18,000, or $6,000 per airplane, per
inspection cycle.
The FAA estimates that 3 airplanes of U.S. registry would be
required to perform the HFEC inspection of certain fuselage
circumferential skin joints that is proposed in this AD action. It
would take approximately 24 work hours per airplane to accomplish this
proposed inspection, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of this proposed inspection on
U.S. operators is estimated to be $4,320, or $1,440 per airplane, per
inspection cycle.
For affected airplanes, it would take approximately 192 work hours
per airplane to accomplish the proposed modification of the cold-bonded
doublers of certain fuselage circumferential skin joints, at an average
labor rate of $60 per work hour. Required parts would cost
[[Page 68064]]
approximately $1,250. Based on these figures, the cost impact of this
proposed modification on U.S. operators is estimated to be $12,770 per
airplane.
The cost impact figures discussed above are 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 99-NM-74-AD.
Applicability: Model 727-100, -100C, and -200 series airplanes;
line numbers 1 through 549 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 (g)(1)
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 delamination of the cold-bonded doublers, which could
result in corrosion of the body skins and doublers, and consequent
reduced structural capability of the fuselage circumferential skin
joints, accomplish the following:
Note 2: For the purposes of this AD, a detailed visual
inspection is defined as: ``An intensive visual examination of a
specific structural area, system, installation, or assembly to
detect damage, failure, or irregularity. Available lighting is
normally supplemented with a direct source of good lighting at
intensity deemed appropriate by the inspector. Inspection aids such
as mirror, magnifying lenses, etc., may be used. Surface cleaning
and elaborate access procedures may be required.''
One-Time Inspection/Replacement
(a) For airplanes on which the modification specified in Boeing
Service Bulletin 727-53-0084, Revision 2, dated June 5, 1972, and
the additional actions (including additional fastener replacement
locations) specified in Boeing Document No. D6-54860, Revision C,
dated December 11, 1989, ``Aging Airplane Service Bulletin
Structural Modification Program--Model 727''; or the modification
specified in Boeing Service Bulletin 727-53-0084, Revision 3, dated
September 28, 1989; HAS been accomplished: Within 36 months after
the effective date of this AD, perform a one-time inspection of the
fuselage circumferential skin joints to determine the type of
fastener installed, in accordance with Figure 7 of the Boeing
Service Bulletin 727-53-0084, Revision 4, dated August 2, 1990.
(1) If no aluminum fasteners are found, no further action is
required by this AD.
(2) If any aluminum fastener is found, prior to further flight,
replace with a steel fastener, in accordance with Boeing Service
Bulletin 727-53-0084, Revision 4, dated August 2, 1990.
Modification
(b) For airplanes listed in Boeing Document No. D6-54860,
Revision C, dated December 11, 1989, ``Aging Airplane Service
Bulletin Structural Modification Program--Model 727'' on which the
modification specified in Boeing Service Bulletin 727-53-0084,
Revision 2, dated June 5, 1972, and the additional actions specified
in Boeing Document No. D6-54860, Revision C, dated December 11,
1989; or the modification specified in Boeing Service Bulletin 727-
53-0084, Revision 3, dated September 28, 1989; has not been
accomplished prior to the effective date of this AD: Prior to the
accumulation of 60,000 total flight cycles, modify the fuselage
circumferential skin joints in accordance with Part IV of the
Accomplishment Instructions of Boeing Service Bulletin 727-53-0084,
Revision 4, dated August 2, 1990. Such action constitutes
terminating action for the modification in that area required by AD
90-06-09.
Repetitive Inspections
(c) For airplanes having line numbers 153, 339, 416, and 540:
Accomplish the requirements of paragraphs (c)(1), (c)(2), and (c)(3)
of this AD at the compliance time specified in those paragraphs.
(1) Within 15 months after the effective date of this AD,
perform an external detailed visual inspection and a low frequency
eddy current (LFEC) inspection of the fuselage circumferential skin
joints to detect corrosion or sealant deterioration, in accordance
with Parts II.A. and II.B. of the Accomplishment Instructions of
Boeing Service Bulletin 727-53-0084, Revision 4, dated August 2,
1990. Repeat the external detailed visual inspection thereafter at
intervals not to exceed 15 months, and repeat the LFEC inspection
thereafter at intervals not to exceed 30 months.
(2) Within 3,000 flight cycles or 30 months after the effective
date of this AD, whichever occurs first, perform a high frequency
eddy current (HFEC) inspection of the fuselage circumferential skin
joints to detect cracking, in accordance with Part II.D. of the
Accomplishment Instructions of Boeing Service Bulletin 727-53-0084,
Revision 4, dated August 2, 1990. Repeat the HFEC inspection
thereafter at intervals not to exceed 4,000 flight cycles or 48
months, whichever occurs first, until accomplishment of paragraph
(f) of this AD.
(3) Within 48 months after the effective date of this AD,
perform an internal detailed visual inspection of the fuselage
circumferential skin joints to detect cracking, disbonding, or
sealant deterioration; in accordance with Part II.C. of the
Accomplishment Instructions of Boeing Service Bulletin 727-53-0084,
Revision 4, dated August 2, 1990. Repeat the internal detailed
visual inspection thereafter at intervals not to exceed 48 months.
Repair
(d) For airplanes having line numbers 153, 339, 416, and 540: If
any discrepancy is detected during any inspection required by
paragraph (c) of this AD, accomplish paragraph (d)(1) or (d)(2) of
this AD, as applicable.
(1) If any corrosion, cracking, or disbonding is detected during
any inspection required by paragraph (c) of this AD, prior to
further flight, repair in accordance with Part III of the
Accomplishment Instructions of Boeing Service Bulletin 727-53-0084,
Revision 4, dated August 2, 1990, except as provided by paragraph
(e) of this AD. No
[[Page 68065]]
further action is required by this AD for that area.
(2) If the sealant has deteriorated but no corrosion, cracking,
or disbonding is detected during any inspection required by
paragraph (c) of this AD, prior to further flight, reseal in
accordance with Figure 5 or 6, as applicable, of Boeing Service
Bulletin 727-53-0084, Revision 4, dated August 2, 1990.
(e) Where the service bulletin specifies that the manufacturer
may be contacted for disposition of certain repair conditions, prior
to further flight, repair in accordance with a method approved by
the Manager, Seattle Aircraft Certification Office (ACO), FAA,
Transport Airplane Directorate; or in accordance with 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, or a
Boeing DER, as required by this paragraph, the approval letter must
specifically reference this AD.
Modification
(f) For airplanes having line numbers 153, 339, 416, and 540:
Prior to the accumulation of 60,000 total flight cycles, or within
3,000 flight cycles after the effective date of this AD, whichever
occurs later, modify the fuselage circumferential skin joints in
accordance with Part IV of the Accomplishment Instructions of Boeing
Service Bulletin 727-53-0084, Revision 4, dated August 2, 1990. Such
action constitutes terminating action for the requirements of
paragraph (c)(2) of this AD.
Alternative Methods of Compliance
(g)(1) 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 Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. 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.
(2) An alternative method of compliance for paragraph (f) of
this AD that provides an acceptable level of safety may be used in
accordance with data meeting the type certification basis of the
airplane approved by a Boeing Company Designated Engineering
Representative who has been authorized by the Manager, Seattle ACO,
to make such findings.
Note 3: 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
(h) 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.
Issued in Renton, Washington, on November 30, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-31477 Filed 12-3-99; 8:45 am]
BILLING CODE 4910-13-P