[Federal Register Volume 62, Number 155 (Tuesday, August 12, 1997)]
[Proposed Rules]
[Pages 43128-43130]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-20438]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 62, No. 155 / Tuesday, August 12, 1997 /
Proposed Rules
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-56-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -
30, -40, and -50
Series Airplanes, and C-9 (Military) 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 McDonnell Douglas Model
DC-9-10, -20, -30, -40, and -50 series airplanes, and C-9 (military)
airplanes. This proposal would require a one-time visual inspection to
determine if all corners of the doorjamb of the forward service door
have been previously modified. The proposal would also require various
repetitive inspections to detect cracks of the fuselage skin and
doubler at all corners of the doorjamb of the forward service door, and
to detect cracks on the skin adjacent to the modification; and various
follow-on actions. This proposal is prompted by reports of fatigue
cracks found in the fuselage skin and doubler at the corners of the
doorjamb of the forward service door. The actions specified by the
proposed AD are intended to detect and correct such fatigue cracking,
which could result in rapid decompression of the fuselage and
consequent reduced structural integrity of the airplane.
DATES: Comments must be received by September 29, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-56-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 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 FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington.
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
(562) 627-5324; fax (562) 627-5210.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-NM-56-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-103, Attention: Rules
Docket No. 97-NM-56-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports of fatigue cracks in the fuselage skin
and doubler at the corners of the doorjamb of the forward service door
on Model DC-9 series airplanes. These cracks were discovered during
inspections conducted as part of the Supplemental Structural Inspection
Document (SSID) program, required by AD 96-13-03, amendment 39-9671 (61
FR 31009, June 19, 1996). Investigation revealed that such cracking was
caused by fatigue-related stress. Fatigue cracking in the fuselage skin
or doubler at the corners of the doorjamb of the forward service door,
if not detected and corrected in a timely manner, could result in rapid
decompression of the fuselage and consequent reduced structural
integrity of the airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved McDonnell Douglas Service
Bulletin DC9-53-279, dated December 10, 1996, and Revision 1, dated May
6, 1997. The service bulletins describes the following procedures:
1. Performing a one-time visual inspection to determine if all
corners of the upper cargo doorjamb have been previously modified;
2. For certain airplanes: Performing a low frequency eddy current
(LFEC) or x-ray inspections to detect cracks of the fuselage skin and
doubler at all corners of the doorjamb of the forward service door;
3. For certain other airplanes: Performing high frequency eddy
current inspection (HFEC) or LFEC, as applicable, to detect cracks on
the skin adjacent to the modification;
4. Conducting repetitive inspections, or modifying the corner skin
of the doorjamb of the forward service door and performing follow-on
action eddy current inspections, if no cracking is detected;
5. Performing repetitive eddy current inspections to detect cracks
on the skin
[[Page 43129]]
adjacent to any corner that has been modified; and
6. Modifying any crack that is found to be 2 inches or less in
length at all corners that have not been modified and performing
follow-on repetitive eddy current inspections.
Accomplishment of the modification will minimize the possibility of
fatigue cracks in the fuselage skin and doubler.
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 a one-time visual inspection to determine if
all corners of the doorjamb of the forward service door have been
previously modified. The proposed AD would also require various
repetitive inspections to detect cracks of the fuselage skin and
doubler at all corners of the doorjamb of the forward service door, and
to detect cracks on the skin adjacent to the modification; and various
follow-on actions. The actions would be required to be accomplished in
accordance with the service bulletins described previously.
Operators should note that, although the service bulletins specify
that the manufacturer must be contacted for disposition of certain
conditions, this proposal would require the repair of those conditions
to be accomplished in accordance with a method approved by the Manager,
Los Angeles Aircraft Certification Office (ACO), FAA,Transport Airplane
Directorate.
Cost Impact
There are approximately 823 McDonnell Douglas Model DC-9-10, -20, -
30, -40, and -50 series airplanes, and C-9 (military) airplanes of the
affected design in the worldwide fleet. The FAA estimates that 575
airplanes of U.S. registry would be affected by this proposed AD.
It would take approximately 1 work hour per airplane to accomplish
the proposed visual inspection, at an average labor rate of $60 per
work hour. Based on these figures, the cost impact of the visual
inspection proposed by this AD on U.S. operators is estimated to be
$34,500, or $60 per airplane.
Should an operator be required to accomplish the proposed HFEC,
LFEC, or x-ray inspection, it would take approximately 1 work hour per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of this inspection proposed by
this AD on U.S. operators is estimated to be $60 per airplane, per
inspection cycle.
Should an operator be required to accomplish the proposed
modification, it would take approximately 30 work hours per airplane to
accomplish, at an average labor rate of $60 per work hour. Required
parts would cost approximately $1,256, $1,420, $5,804, or $6,113 per
airplane, depending on the service kit purchased. Based on these
figures, the cost impact of the modification proposed by this AD on
U.S. operators is estimated to be $3,056, $3,220, $7,604, or $7,913 per
airplane, respectively.
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:
McDonnell Douglas: Docket 97-NM-56-AD.
Applicability: Model DC-9-10, -20, -30, -40, and -50 series
airplanes, and C-9 (military) airplanes, as listed in McDonnell
Douglas Service Bulletin DC9-53-279, Revision 1, dated May 6, 1997;
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 (f) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To detect and correct fatigue cracking in the fuselage skin or
doubler at the corners of the doorjamb of the forward service door,
which could result in rapid decompression of the fuselage and
consequent reduced structural integrity of the airplane, accomplish
the following:
Note 2: Where there are differences between the service bulletin
and the AD, the AD prevails.
Note 3: The words ``repair'' and ``modify/modification'' in this
AD and the referenced service bulletin are used interchangeably.
Note 4: This AD is related to AD 96-13-03, amendment 39-9671,
(61 FR 31009, June 19, 1996), and will affect Principal Structural
Element (PSE) 53.09.033 of the DC-9 Supplemental Inspection Document
(SID).
(a) Prior to the accumulation of 50,000 total landings, or
within 3,225 landings after the effective date of this AD, whichever
occurs later, perform a one-time visual inspection to determine if
the corners of the doorjamb of the forward service door have been
modified prior to the effective date of this AD.
(b) Group 1. If the visual inspection required by paragraph (a)
of this AD reveals that the corners of the upper cargo doorjamb have
not been modified, prior to further flight, perform a low frequency
eddy current (LFEC) or x-ray inspection to detect cracks of the
fuselage skin and doubler at all corners of the doorjamb of the
forward service door, in accordance with McDonnell Douglas Service
Bulletin DC9-53-279, dated December 10, 1996, or Revision 1, dated
May 6, 1996.
[[Page 43130]]
(1) Condition 1. If no crack is detected during any inspection
required by paragraph (b) of this AD, accomplish either paragraph
(b)(1)(i) or (b)(1)(ii) of the AD.
(i) Option 1. Repeat the inspections as follows until paragraph
(b)(1)(ii) of this AD is accomplished:
(A) If the immediately preceding inspection was conducted using
LFEC techniques, conduct the next inspection within 3,225 landings.
(B) If the immediately preceding inspection was conducted using
x-ray techniques, conduct the next inspection within 3,075 landings.
(ii) Option 2. Prior to further flight, modify the corners of
the doorjamb of the forward service door in accordance with the
service bulletin; this modification constitutes terminating action
for the repetitive inspection requirements of paragraph (b)(1)(i) of
this AD. Prior to the accumulation of 28,000 landings after
accomplishment of the modification, perform a high frequency eddy
current (HFEC) inspection to detect cracks on the skin adjacent to
the modification, in accordance with the service bulletin. Within
20,000 landings after accomplishment of the HFEC inspection, perform
an eddy current inspection to detect cracks in the subject area, in
accordance with the service bulletin.
(A) If no crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (b)(1)(ii) of this AD, repeat the eddy current inspection
thereafter at intervals not to exceed 20,000 landings.
(B) If any crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (b)(1)(ii) of this AD, repair it in accordance with a
method approved by the Manager, Los Angeles ACO.
(2) Condition 2. If any crack is found during any inspection
required by paragraph (b) of this AD and the crack is 2 inches or
less in length: Prior to further flight, modify it in accordance
with the service bulletin. Prior to the accumulation of 28,000
landings after accomplishment of the modification, perform a HFEC
inspection to detect cracks on the skin adjacent to the
modification, in accordance with the service bulletin. Within 20,000
landings after accomplishment of the HFEC inspection, perform an
eddy current inspection to detect cracks in the subject area, in
accordance with the service bulletin.
(i) If no crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (b)(2) of this AD, repeat the eddy current inspection
thereafter at intervals not to exceed 20,000 landings.
(ii) If any crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (b)(2) of this AD, repair it in accordance with a method
approved by the Manager, Los Angeles ACO.
(3) Condition 3. If any crack is found during any inspection
required by this paragraph and the crack is greater than 2 inches in
length: Prior to further flight, repair it in accordance with a
method approved by the Manager, Los Angeles ACO.
(c) Group 2, Condition 1. If the visual inspection required by
paragraph (a) of this AD reveals that the corners of the doorjamb of
the forward service door have been modified in accordance with the
DC-9 Structural Repair Manual (SRM) (using a steel doubler),
accomplish either paragraph (c)(1) or (c)(2) of this AD in
accordance with McDonnell Douglas Service Bulletin DC9-53-279, dated
December 10, 1996, or Revision 1, dated May 6, 1997.
(1) Option 1. Prior to the accumulation of 6,000 landings after
the effective date of this AD, perform a HFEC inspection to detect
cracks on the skin adjacent to the modification in accordance with
the service bulletin. Within 3,000 landings after accomplishment of
the HFEC inspection, perform an eddy current inspection to detect
cracks in the subject area, in accordance with the service bulletin.
(i) If no crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (c)(1) of this AD, repeat the eddy current inspection
thereafter at intervals not to exceed 3,000 landings.
(ii) If any crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (c)(1) of this AD, repair it in accordance with a method
approved by the Manager, Los Angeles ACO.
(2) Option 2. Prior to further flight, modify the corners of the
doorjamb of the forward service door in accordance with the service
bulletin. Prior to the accumulation of 28,000 landings after
accomplishment of the modification, perform a HFEC inspection to
detect cracks on the skin adjacent to the modification, in
accordance with the service bulletin. Within 20,000 landings after
accomplishment of the HFEC inspection, perform an eddy current
inspection to detect cracks in the subject area, in accordance with
the service bulletin.
(i) If no crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (c)(2) of this AD, repeat the eddy current inspection
thereafter at intervals not to exceed 20,000 landings.
(ii) If any crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (c)(2) of this AD, repair it in accordance with a method
approved by the Manager, Los Angeles ACO.
(d) Group 2, Condition 2. If the visual inspection required by
paragraph (a) of this AD reveals that the corners of the doorjamb of
the forward service door have been modified in accordance with DC-9
SRM or Service Rework Drawing (using an aluminum doubler), prior to
the accumulation of 28,000 landings since accomplishment of the
modification, or within 3,225 after the effective date of this AD,
whichever occurs later, perform an HFEC inspection to detect cracks
on the skin adjacent to the modification, in accordance with
McDonnell Douglas Service Bulletin DC9-53-279, dated December 10,
1996, or Revision 1, dated May 6, 1997. Within 20,000 landings after
accomplishment of the HFEC inspection, perform an eddy current
inspection to detect cracks in the subject area, in accordance with
the service bulletin.
(1) If no crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (d) of this AD, repeat the eddy current inspection
thereafter at intervals not to exceed 20,000 landings.
(2) If any crack is detected on the skin adjacent to the
modification during any eddy current inspection required by
paragraph (d) of this AD, repair it in accordance with a method
approved by the Manager, Los Angeles ACO.
(e) Group 2, Condition 3. If the visual inspection required by
paragraph (a) of this AD reveals that the corners of the doorjamb of
the forward service door have been modified, but not in accordance
with DC-9 SRM or Service Rework Drawing, prior to further flight,
repair it in accordance with a method approved by the Manager, Los
Angeles ACO.
(f) 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 5: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(g) 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 July 29, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-20438 Filed 8-11-97; 8:45 am]
BILLING CODE 4910-13-U