[Federal Register Volume 60, Number 156 (Monday, August 14, 1995)]
[Rules and Regulations]
[Pages 41795-41798]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-19120]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-14-AD; Amendment 39-9330; AD 95-17-01]
Airworthiness Directives; Boeing Model 707 and 720 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing Model 707 and 720 series airplanes,
that currently requires repetitive visual and dye penetrant inspections
to detect cracks in areas of the upper forward skin panels of the wing
center section, and repair, if necessary. It also provides an optional
terminating modification for the repetitive inspections. This amendment
requires repetitive visual and eddy current inspections to detect
cracks in areas of the upper forward skin panels of the wing center
section, and repair, if necessary. This amendment is prompted by
reports indicating that the inspections required by the existing AD are
not effective in detecting fatigue cracks in a timely manner. The
actions specified by this AD are intended to prevent fatigue cracking
and subsequent failure of the upper forward skin panels of the wing
center section.
DATES: Effective on September 13, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 13, 1995.
ADDRESSES: 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 Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 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: Phil Forde, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington, 98055-4056; telephone (206) 227-2771; fax (206) 227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to add an airworthiness directive
(AD), applicable to certain Boeing Model 707 and 720 series airplanes,
was published as a supplemental notice of proposed rulemaking (NPRM) in
the Federal Register on February 7, 1995 (60 FR 7143). That
supplemental NPRM proposed to supersede AD 68-18-03, amendment 39-2056.
That AD currently requires repetitive visual and dye penetrant
inspections to detect cracks on the upper forward skin panels of the
wing center section, and repair, if necessary. It also provides an
optional terminating modification for the repetitive inspections. The
supplemental NPRM proposed to require repetitive visual and eddy
current inspections to detect cracks on the upper forward skin panels
of the wing center section, and repair, if necessary.
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.
The commenter requests that paragraph (e) of the proposal be
revised to allow that the terminating action specified in that
paragraph be accomplished in accordance with procedures contained in
revisions prior to Revision 6 of Boeing Service Bulletin 2590, provided
that, in addition to the installation of reinforcing stiffeners, the
forward skin panel is replaced. The commenter indicates that the
modifications described in these earlier revisions of the service
bulletin are identical to those specified in Revisions 6 and
subsequent. The commenter adds that the ``aging fleet document''
(Boeing Document D6-54496), which addresses the affected airplanes,
specifies that modifications accomplished in accordance with the
original issue through Revision 8 of Boeing Service Bulletin 2590 are
considered to be terminating action, provided that new forward skin
panels are installed. The commenter states that the inconsistency
[[Page 41796]]
between the proposal and the ``aging fleet document'' in this regard
has caused confusion among some operators as to whether airplanes
modified in accordance with earlier revisions of the service bulletin
are considered to be in compliance with the proposed AD.
The FAA concurs partially. The FAA has re-examined the earlier
revisions of the service bulletin, and has determined that the original
issue and Revisions 1 through 3 of the service bulletin were issued as
telegraphic documents. These revisions do not adequately address
procedures for accomplishing the terminating modifications in
sufficient detail. Therefore, the FAA does not consider these revisions
to be acceptable for accomplishment of the terminating modification
specified in this AD. However, Revision 4 does provide adequate
procedures for accomplishing the terminating modification for Model 720
series airplanes, provided that the forward skin panel also is replaced
in accordance with the service bulletin. In addition, Revision 5
contains adequate information for accomplishment of the terminating
modification for both Model 707 and 720 series airplanes, provided that
the forward skin panel also is replaced in accordance with the service
bulletin. These determinations have been specified in paragraphs (e)
and (f) of the final rule for Models 707 and 720 series airplanes,
respectively.
Certain service bulletin titles were referenced incorrectly in NOTE
2 and paragraphs (c)(1), (c)(2), and (c)(3) of the supplemental NPRM as
``Boeing Master Inspection Service Bulletins.'' The appropriate titles
for these service documents are ``Boeing Service Bulletins.'' The FAA
has revised the note and those paragraphs of the final rule
accordingly. In addition, the FAA has added references to specific page
numbers of those service bulletins for the convenience of operators.
In addition, paragraph (e) of the supplemental NPRM did not specify
that Revision 6 of Boeing Service Bulletin 2590 was issued as an alert
service bulletin. The final rule has been revised accordingly.
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 with the changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
-There are approximately 416 Model 707 and 720 series airplanes of
the affected design in the worldwide fleet. The FAA estimates that 82
airplanes of U.S. registry will be affected by this AD, that it will
take approximately 32 work hours per airplane to accomplish the
required actions, and that the average labor rate is $60 per work hour.
Based on these figures, the total cost impact of the AD on U.S.
operators is estimated to be $157,440, or $1,920 per airplane, per
inspection cycle. -
The total 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. -
Should an operator elect to accomplish the optional terminating
action that is provided by this AD action, it will take approximately
1,250 work hours to accomplish it, at an average labor rate of $60 per
work hour. The cost of required parts is approximately $45,000 per
airplane. Based on these figures, the total cost impact of the optional
terminating action is estimated to be $120,000 per airplane. -
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. -
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 -
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), 40101, 40113, 44701.
Sec. 39.13 [Amended] -
2. Section 39.13 is amended by removing amendment 39-2056, and by
adding a new airworthiness directive (AD), amendment 39- , to read as
follows:
95-17-01 Boeing: Amendment 39-9330. Docket 94-NM-14-AD. Supersedes
AD 68-18-03, Amendment 39-2056.
-Applicability: Model 707 and 720 series airplanes; as listed in
Boeing Service Bulletin 2590, Revision 11, dated December 12, 1991;
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 use the authority
provided in paragraph (g) of this AD to request approval from the
FAA. This approval may address either no action, if the current
configuration eliminates the unsafe condition; or different actions
necessary to address the unsafe condition described in this AD. Such
a request should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
-Compliance: Required as indicated, unless accomplished
previously. -
To prevent fatigue cracking and subsequent failure of the upper
forward skin panels of the wing center section, accomplish the
following: -
(a) For Model 707-100, -200, -300, -300B, -300C, and -400 series
airplanes on which no bulb angle stiffeners have been installed in
accordance with Boeing Service Bulletin 2590: Perform a visual
inspection and an eddy current inspection to detect cracks in the
areas of the upper forward skin of the wing center section specified
in paragraphs b. and f.(1) of Part I of the Accomplishment
Instructions of Boeing Service Bulletin 2590, Revision 8, dated June
2, 1972; Revision 9, dated March 14, 1975; Revision 10, dated
January 31, 1991; or Revision 11, dated December 12, 1991. Perform
the inspections at the time specified in paragraph (a)(1) or (a)(2)
of this AD, as applicable, in accordance with the procedures
specified in the service bulletin. Repeat these inspections
thereafter at intervals not to exceed 450 landings.
-(1) For Model 707-300, -300B, -300C, and -400 series airplanes:
Inspect at the later of the times specified in paragraphs (a)(1)(i)
and (a)(1)(ii) of this AD. -
[[Page 41797]]
(i) Prior to the accumulation of 6,000 total landings; or
(ii) Within 500 landings or 18 months after the effective date
of this AD, whichever occurs first.
(2) For Model 707-100 and -200 series airplanes: Inspect at the
later of the times specified in paragraphs (a)(2)(i) and (a)(2)(ii)
of this AD.
(i) Prior to the accumulation of 6,400 total landings; or
(ii) Within 500 landings or 18 months after the effective date
of this AD, whichever occurs first.-
(b) For Model 720 and 720B series airplanes on which no bulb
angle stiffeners have been installed in accordance with Boeing
Service Bulletin 2590: Perform a visual inspection and an eddy
current inspection to detect cracks in the area of the upper forward
skin of the wing center section specified in paragraph b. of Part I
of the Accomplishment Instructions of Boeing Service Bulletin 2590,
Revision 8, dated June 2, 1972; Revision 9, dated March 14, 1975;
Revision 10, dated January 31, 1991; or Revision 11, dated December
12, 1991. Perform the inspections at the later of the times
specified in paragraphs (b)(1) and (b)(2) of this AD, in accordance
with the procedures specified in the service bulletin. Repeat these
inspections thereafter at intervals not to exceed 450 landings. -
(1) Prior to the accumulation of 4,000 total landings; or -
(2) Within 500 landings or 18 months after the effective date of
this AD, whichever occurs first. -
(c) For Model 720 and 720B, and 707-100, -200, -300, -300B, -
300C, and -400 series airplanes on which bulb angle stiffeners have
been installed, but on which the wing skin has not been replaced, in
accordance with Boeing Service Bulletin 2590: Accomplish the
inspections required by paragraph (c)(1), (c)(2), or (c)(3) of this
AD, as applicable, in accordance with Boeing Service Bulletin 2590,
Revision 11, dated December 12, 1991. Repeat these inspections
thereafter at intervals not to exceed 1,000 landings.
-Note 2: Revision 11 of Boeing Service Bulletin 2590 is part of
Boeing Service Bulletins 3484 (for Model 707-100 and -200 series
airplanes), 3485 (for Model 720 and 720B series airplanes), and 3486
(for Model 707-300, -300B, -300C, and -400 series airplanes), all
dated December 12, 1991. Boeing Service Bulletin 2590 references
these service bulletins as additional sources of service information
concerning accomplishment of the inspections required by paragraph
(c) of this AD.
-(1) For Model 720 and 720B series airplanes: Perform a visual
and an eddy current inspection to detect cracks in the areas of the
upper forward skin of the wing center section specified on pages 34
and 35 of Boeing Service Bulletin 3485, dated December 12, 1991, at
the later of the times specified in paragraphs (c)(1)(i) and
(c)(1)(ii) of this AD. -
(i) Prior to the accumulation of 2,200 landings after
installation of the bulb angle stiffeners; or -
(ii) Within 500 landings or 18 months after the effective date
of this AD, whichever occurs first. -
(2) For Model 707-300, -300B, -300C, and -400 series airplanes:
Perform a visual and an eddy current inspection to detect cracks in
the areas of the upper forward skin of the wing center section
specified on page 55 of Boeing Service Bulletin 3486, dated December
12, 1991, at the later of the times specified in paragraphs
(c)(2)(i) and (c)(2)(ii) of this AD. -
(i) Prior to the accumulation of 2,200 landings after
installation of the bulb angle stiffeners; or
(ii) Within 500 landings or 18 months after the effective date
of this AD, whichever occurs first.
(3) For Model 707-100 and -200 series airplanes: Perform a
visual and an eddy current inspection to detect cracks in the areas
of the upper forward skin of the wing center section specified on
pages 37 and 38 of Boeing Service Bulletin 3484, dated December 12,
1991, at the later of the times specified in paragraphs (c)(3)(i)
and (c)(3)(ii) of this AD.
(i) Prior to the accumulation of 2,200 landings after
installation of the bulb angle stiffeners; or
(ii) Within 500 landings or 18 months after the effective date
of this AD, whichever occurs first.
(d) If any crack is found during any inspection required by
paragraph (a), (b), or (c) of this AD, prior to further flight,
repair in accordance with Part II of the Accomplishment Instructions
of Boeing Service Bulletin 2590, Revision 7, dated September 22,
1969; Revision 8, dated June 2, 1972; Revision 9, dated March 14,
1975; Revision 10, dated January 31, 1991; or Revision 11, dated
December 12, 1991.
(e) For Model 707 series airplanes: Accomplishment of the
``Reinforcing Stiffener Installation and Skin Panel Replacement'' in
accordance with Part III of the Accomplishment Instructions of
Boeing Alert Service Bulletin 2590, Revision 6, dated July 8, 1968;
Boeing Service Bulletin 2590, Revision 7, dated September 22, 1969,
Revision 8, dated June 2, 1972, Revision 9, dated March 14, 1975,
Revision 10, dated January 31, 1991, or Revision 11, dated December
12, 1991; constitutes terminating action for the inspections
required by paragraphs (a), (b), and (c) of this AD. Accomplishment
of the reinforcement and replacement in accordance with Boeing Alert
Service Bulletin 2590, Revision 5, dated September 20, 1967, also is
considered acceptable for compliance with paragraph (e) of this AD
provided that the forward skin panel also is replaced in accordance
with that service bulletin.
(f) For Model 720 series airplanes: Accomplishment of the
``Reinforcing Stiffener Installation and Skin Panel Replacement'' in
accordance with Part III of the Accomplishment Instructions of
Boeing Alert Service Bulletin 2590, Revision 6, dated July 8, 1968;
Boeing Service Bulletin 2590, Revision 7, dated September 22, 1969,
Revision 8, dated June 2, 1972, Revision 9, dated March 14, 1975,
Revision 10, dated January 31, 1991, or Revision 11, dated December
12, 1991; constitutes terminating action for the inspections
required by paragraphs (a), (b), and (c) of this AD. Accomplishment
of the reinforcement and replacement in accordance with Boeing Alert
Service Bulletin 2590, Revision 4, dated May 26, 1967, or Revision
5, dated September 20, 1967, also is considered acceptable for
compliance with paragraph (f) of this AD provided that the forward
skin panel also is replaced in accordance with that service
bulletin.
(g) 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.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(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.
(i) The actions shall be done in accordance with the following
service documents:
Boeing Alert Service Bulletin 2590, Revision 4, dated May 26, 1967;
Boeing Alert Service Bulletin 2590, Revision 5, dated September 20,
1967;
Boeing Alert Service Bulletin 2590, Revision 6, dated July 8, 1968;
Boeing Service Bulletin 2590, Revision 7, dated September 22, 1969;
Boeing Service Bulletin 2590, Revision 8, dated June 2, 1972;
Boeing Service Bulletin 2590, Revision 9, dated March 14, 1975;
Boeing Service Bulletin 2590, Revision 10, dated January 31, 1991;
Boeing Service Bulletin 2590, Revision 11, dated December 12, 1991;
Pages 37 and 38 of Boeing Service Bulletin 3484, dated December 12,
1991;
Pages 34 and 35 of Boeing Service Bulletin 3485, dated December 12,
1991; and
Pages 55 and 56 of Boeing Service Bulletin 3486, dated December 12,
1991.
Boeing Alert Service Bulletin 2590, Revision 6, dated July 8,
1968, contains the following specified effective pages:
[[Page 41798]]
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Revision
level
Page No. shown on Date shown on page
page
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1, 3-5, 7, 9, 10, 14, 16......... 6 July 8, 1968.
2, 6, 8, 11-13, 15............... 5 September 20, 1967.
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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 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.
(j) This amendment becomes effective on September 13, 1995.
Issued in Renton, Washington, on July 28, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-19120 Filed 8-11-95; 8:45 am]
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