[Federal Register Volume 62, Number 22 (Monday, February 3, 1997)]
[Rules and Regulations]
[Pages 4906-4908]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-2222]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-235-AD; Amendment 39-9911; AD 97-03-05]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9 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 McDonnell Douglas DC-9 series airplanes,
that currently requires repetitive visual inspections to detect
corrosion and cracking of the fuselage upper skin and frames in the
area of the loop antenna assemblies of the automatic direction finder
(ADF), and repair, if necessary. This amendment adds a requirement to
perform a visual and an eddy current inspection of the fuselage forward
upper skin under the antennas, followed by the reinstallation of the
ADF antennas using an improved procedure. This amendment is prompted by
the development of a modification of the ADF antenna installation that
constitutes terminating action for the required repetitive visual
inspections. The actions specified by this AD are intended to prevent
rapid decompression of the fuselage, significant structural damage, and
subsequent reduced structural integrity of the airplane, due to
problems associated with corrosion and fatigue cracking in the subject
area.
DATES: Effective March 10, 1997.
The incorporation by reference of McDonnell Douglas Alert Service
Bulletin DC9-53A282, dated March 20, 1996, listed in the regulations,
was approved previously by the Director of the Federal Register, in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of April 15, 1996
(61 FR 15882, April 10, 1996).
The incorporation by reference of McDonnell Douglas Service
Bulletin DC9-53-284, dated August 20, 1996, listed in the regulations,
is approved by the Director of the Federal Register as of March 10,
1997.
ADDRESSES: The service information referenced in this AD may be
obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard,
Long Beach, California 90846, Attention: Technical Publications
Business Administration, Department C1-L51 (2-60). 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 FAA, Transport Airplane Directorate, Los Angeles
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood,
California; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Wahib Mina, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone
(310) 627-5324; fax (310) 627-5210.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 96-07-51,
amendment 39-9562 (61 FR 15882, April 10, 1996), which is applicable to
certain McDonnell Douglas DC-9 series airplanes, was published in the
Federal Register on October 23, 1996 (61 FR 54969). That action
proposed to continue to require repetitive internal
[[Page 4907]]
visual inspections to detect corrosion and cracking of the fuselage
forward upper skin and to detect cracking of the fuselage frame in the
area of the forward and aft loop antenna assemblies of the automatic
direction finder (ADF), as is currently required by AD 97-07-01.
However, it also proposed to add a requirement to perform a visual and
an eddy current inspection of the fuselage forward upper skin under the
antennas, followed by the reinstallation of the ADF antennas using an
improved procedure. Accomplishment of these actions would constitute
terminating action for the required repetitive inspections.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposal
Five commenters support the proposed AD.
Request To Extend Compliance Time for Certain Airplanes
One commenter supports the intent of the proposal, but requests
that the compliance time for accomplishing the terminating action be
extended from the proposed 24 months to 48 months for those airplanes
on which the antenna has been reinstalled within the past 4 years. The
commenter notes that the compliance schedule for the terminating action
does not address the condition where the ADF antenna was previously
removed and the fuselage skin inspection and repaired, i.e., in
accordance with the previously issued AD 96-07-51. The commenter
considers that, for the repaired airplanes, a higher level of safety
has been achieved than if no such repair had been performed.
Considering the number of airplanes that are affected by this AD
(approximately 403), allowing an extension of the time for installing
the final fix on the previously repaired airplanes also will minimize
the operational impact of the AD on operators.
The FAA concurs with the commenter's request. The FAA acknowledges
that AD 96-07-51 (as well as this new AD) requires that, if any
cracking or corrosion is found and it is within certain limits, the
area must be repaired in accordance with either the Structural Repair
Manual (SRM) or a manner approved by the FAA. In consideration of the
increased structural integrity of the area that is provided by such
repairs, the FAA finds that the risk of additional cracking is reduced
and accomplishment of the terminating action may be extended for an
additional 2 years (for a total of 4 years) without adversely affecting
safety. Paragraph (b) of the final rule has been revised accordingly.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the change previously
described. The FAA has determined that this change will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
There are approximately 569 McDonnell Douglas Model DC-9 series
airplanes of the affected design in the worldwide fleet. The FAA
estimates that 403 airplanes of U.S. registry will be affected by this
proposed AD.
The inspections that were previously required by AD 96-07-51 and
retained in this new AD take approximately 5 work hours per airplane to
accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact of the currently required actions on
U.S. operators is estimated to be $120,900, or $300 per airplane, per
inspection.
The terminating action that is required by this new AD will take
approximately 16 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the new requirements of this AD on U.S. operators is
estimated to be $386,880, or $960 per airplane.
The cost impact figures discussed above are 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.
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.
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), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-9562 (61 FR
15882, April 10, 1996), and by adding a new airworthiness directive
(AD), amendment 39-9911, to read as follows:
97-03-05 McDonnell Douglas: Amendment 39-9911. Docket 96-NM-235-AD.
Supersedes AD 96-07-51, Amendment 39-9562.
Applicability: Model DC-9 series airplanes having fuselage
numbers 001 through 631 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 otherwise
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)(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 rapid decompression of the fuselage, significant
structural damage, and subsequent reduced structural integrity of
the airplane, due to problems associated with
[[Page 4908]]
corrosion and fatigue cracking, accomplish the following:
(a) Within 15 days after April 15, 1996 (the effective date of
AD 96-07-51, amendment 39-9562): Perform an internal visual
inspection to detect corrosion and cracking of the fuselage forward
upper skin and to detect cracking of the fuselage frame in the area
of the forward and aft loop antenna assemblies of the automatic
direction finder (ADF), in accordance with McDonnell Douglas Alert
Service Bulletin DC9-53A282, dated March 20, 1996.
(1) If no corrosion or cracking is detected: Repeat the visual
inspection required by paragraph (a) of this AD thereafter at
intervals not to exceed 6 months.
(2) If any corrosion or cracking is detected that is within the
limits specified in Chapter 53-04, Figure 29, of the DC-9 Structural
Repair Manual (SRM): Prior to further flight, repair in accordance
with Chapter 53-04, Figure 29, of the SRM. Thereafter, repeat the
visual inspection required by paragraph (a) of this AD at intervals
not to exceed 6 months.
(3) If any corrosion or cracking is detected in the fuselage
forward upper skin, or if any cracking is detected in the fuselage
frame, and that corrosion or cracking is outside the limits
specified in Chapter 53-04, Figure 29, of the SRM: Prior to further
flight, repair in accordance with a method approved by the Manager,
Los Angeles Aircraft Certification Office (ACO), FAA, Transport
Airplane Directorate.
(b) At the applicable time specified in paragraph (b)(1) of
(b)(2) of this AD, remove the ADF antennas and perform both a visual
inspection and a high frequency eddy current inspection to detect
corrosion and cracking of the fuselage forward upper skin under the
antennas, in accordance with McDonnell Douglas Service Bulletin DC9-
53-284, dated August 20, 1996.
(1) For airplanes on which the ADF antenna has not been
previously removed and the fuselage skin has not been previously
inspected for evidence of corrosion, within the last 4 years prior
to the effective date of this AD: Accomplish the inspections within
2 years after the effective date of this AD.
(2) For airplanes on which the ADF antenna has been previously
removed and the fuselage skin has been previously inspected for
evidence of corrosion and/or repaired within the last 4 years prior
to the effective date of this AD: Accomplish the inspections within
4 years after the effective date of this AD.
(c) As a result of the inspections required by paragraph (b) of
this AD, accomplish the applicable action specified in paragraph
(c)(1), (c)(2), or (c)(3) of this AD. Accomplishment of the actions
specified in paragraph (c)(1) or (c)(2) constitutes terminating
action for the requirements of paragraphs (a)(1) and (a)(2) of this
AD.
(1) If no cracking or corrosion is detected: Prior to further
flight, reinstall the ADF antennas using the improved installation
procedure in accordance with McDonnell Douglas Service Bulletin DC9-
53-284, dated August 20, 1996. Thereafter, no further action is
required by this AD.
(2) If any cracking or corrosion is detected that is within the
limits specified in Chapter 53-04 of the DC-9 Structural Repair
Manual (SRM): Prior to further flight, repair in accordance with
Chapter 53-04 of the DC-9 SRM, and reinstall the ADF antennas using
the improved installation procedure in accordance with McDonnell
Douglas Service Bulletin DC9-53-284, dated August 20, 1996.
Thereafter, no further action is required by this AD.
(3) If any cracking or corrosion is detected that is outside the
limits specified in Chapter 53-04 of the SRM: Prior to further
flight, repair in accordance with a method approved by the Manager,
Los Angeles Certification Office (ACO), FAA, Transport Airport
Directorate.
(d)(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, Los Angeles 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, Los Angeles ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(2) Alternative methods of compliance, approved in accordance
with AD 96-07-71, amendment 39-9562, are approved as alternative
methods of compliance with this AD.
(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.
(f) The actions shall be done in accordance with McDonnell
Douglas Alert Service Bulletin DC9-53A282, dated March 20, 1996; and
McDonnell Douglas Service Bulletin DC9-53-284, dated August 20,
1996. The incorporation by reference of the former service bulletin
was approved previously by the Director of the Federal Register, in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of April 15,
1996 (61 FR 15882, April 10, 1996). The incorporation by reference
of the latter service bulletin 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 McDonnell Douglas Corporation, 3855
Lakewood Boulevard, Long Beach, California 90846, Attention:
Technical Publications Business Administration, Department C1-L51
(2-60). Copies may be inspected at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
FAA, Transport Airplane Directorate, Los Angeles Aircraft
Certification Office, 3960 Paramount Boulevard, Lakewood,
California; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
(g) This amendment becomes effective on March 10, 1997.
Issued in Renton, Washington, on January 23, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-2222 Filed 1-31-97; 8:45 am]
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