[Federal Register Volume 66, Number 183 (Thursday, September 20, 2001)]
[Proposed Rules]
[Pages 48384-48388]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-23417]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-324-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, 
-30, -40, and -50 Series Airplanes, and C-9 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

[[Page 48385]]

certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series 
airplanes, and C-9 airplanes. This proposal would require repetitive 
general visual and x-ray inspections to detect cracks of the upper and 
lower corners and upper center of the door cutout of the aft pressure 
bulkhead; corrective actions, if necessary; and follow-on actions. For 
certain airplanes, the proposal also would require modification of the 
ventral aft pressure bulkhead. This action is necessary to detect and 
correct fatigue cracks in the corners and upper center of the door 
cutout of the aft pressure bulkhead, which could result in rapid 
decompression of the fuselage and consequent reduced structural 
integrity of the airplane. This action is intended to address the 
identified unsafe condition.

DATES: Comments must be received by November 5, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-324-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-324-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data 
and Service Management, Dept. C1-L5A (D800-0024). This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California.

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; (562) 627-5210; fax .

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 action may be changed in 
light of the comments received. Submit comments using the following 
format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-324-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. 2000-NM-324-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that the repetitive x-ray 
inspections required by AD 85-01-02 R1, amendment 39-5241 (51 FR 6101, 
February 20, 1986), do not adequately detect fatigue cracks in all 
layers of a repaired or modified aft pressure bulkhead. Fatigue cracks 
in the corners and upper center of the door cutout of the aft pressure 
bulkhead, if not detected and corrected, could result in rapid 
decompression of the fuselage and consequent reduced structural 
integrity of the airplane.

Other Relevant Rulemaking

    The FAA normally would issue a proposed AD to supersede AD 85-01-02 
R1 to continue to require the existing requirements, until the new 
proposed actions that address the identified unsafe condition are done. 
This would involve restating the existing requirements of AD 85-01-02 
R1 in the new proposed AD. Because of the complexity of the 
requirements of AD 85-01-02 R1, we plan to issue this proposed AD as a 
``stand-alone'' AD that would not supersede AD 85-01-02 R1. We have 
included a paragraph in this proposed AD that terminates the repetitive 
inspection requirements of AD 85-01-02 R1. Once a final rule has been 
issued and it becomes effective, we plan to rescind AD 85-01-02 R1.
    The FAA has previously issued AD 96-10-11, amendment 39-9618 (61 FR 
24675, May 16, 1996), which requires certain inspections and structural 
modifications. Accomplishment of the modification (reference Boeing 
(McDonnell Douglas) Service Bulletin DC9-53-166) required by paragraph 
(d) or (e) of AD 96-10-11 (which references ``DC-9/MD-80 Aging Aircraft 
Service Action Requirements Document'' (SARD), McDonnell Douglas Report 
No. MDC K1572, Revision A, dated June 1, 1990, as the appropriate 
source of service information for accomplishing the modification) 
terminates the repetitive inspection requirements of paragraphs (b) and 
(c) of this AD.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin DC9-53-137, Revision 07, dated February 6, 2001, which 
describes procedures for repetitive general visual and x-ray 
inspections to detect cracks of the upper and lower corners and upper 
center of the door cutout of the aft pressure bulkhead; corrective 
actions, if necessary; and follow-on actions. The corrective actions 
include modification of the bulkhead; trim forward facing flange; stop 
drill ends of cracks; install repair kit; replacement of cracked part 
with new parts; and installation of additional doublers. The follow-on 
actions include repetitive visual and eddy current inspections of the 
upper and lower corners and upper center of the door cutout of the aft 
pressure bulkhead door. Accomplishment of the general visual and x-ray 
inspections would eliminate the need for the

[[Page 48386]]

repetitive inspection requirements of AD 85-01-02 R1.
    The FAA also has reviewed and approved McDonnell Douglas DC-9 
Service Bulletin 53-165, Revision 3, dated May 3, 1989, which describes 
procedures for modification of the ventral aft pressure bulkhead 
structure (including cutting and removing flange of the upper; cutting 
and removing the lower flange of formers and replacing it with a clip; 
installing pads at the outboard end clips of formers; and replacing 
clearance fit bolts at the upper corner doubler angles with 
interference fit Hi-Lok pins and monel rivets).
    In addition, the FAA has reviewed and approved McDonnell Douglas 
DC-9 Service Bulletin 53-157, Revision 1, dated January 7, 1985, which 
describes, for certain airplanes, procedures for modification of the 
ventral aft pressure bulkhead (including encapsulating the head and nut 
of the attachments and applying a fillet seal of sealant around parts 
located on the forward and aft sides of the aft pressure bulkhead; and 
applying a soft film corrosion inhibiting compound to the forward and 
aft sides of the aft pressure bulkhead. For certain airplanes, these 
procedures must be done in conjunction with those in McDonnell Douglas 
DC-9 Service Bulletin 53-165.

FAA's Determination

    The FAA finds that if, after the effective date of this AD, the 
airplane is operated without cabin pressurization and a placard that 
prohibits operation with cabin pressurization is installed in the 
cockpit in full view of the pilot, the inspections and modification 
specified in the service bulletins described previously are not 
necessary.

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 bulletins described previously; except if, after the 
effective date of this AD, the airplane is operated without cabin 
pressurization and a placard that prohibits operation with cabin 
pressurization is installed in the cockpit in full view of the pilot.

Differences Between the Proposed AD and a Certain Referenced 
Service Bulletin

    McDonnell Douglas DC-9 Service Bulletin 53-165, Revision 3, dated 
May 3, 1989, and McDonnell Douglas Service Bulletin DC9-53-137, 
Revision 07, dated February 6, 2001, recommend compliance times with 
only a ``threshold'' (i.e., before the airplane accumulates 15,000 
total landings, within 15,000 landings after the bulkhead modification, 
and at the earliest practical maintenance period feasible on airplanes 
that have accumulated more than 15,000 landings, respectively). These 
service bulletins do not provide a ``grace period'' for airplanes that 
have already reached (or will soon reach) the 15,000-landing threshold, 
which would result in some airplanes being in immediate non-compliance 
with the rule upon reaching the stated number of landings. Therefore, 
the compliance times specified in paragraphs (a), (d)(1), and (d)(2) of 
this proposed AD include a grace period of ``within 4,000 landings 
after the effective date of this AD.'' The FAA finds such a grace 
period for completing the required actions to be warranted, in that it 
represents an appropriate interval of time allowable for affected 
airplanes to continue to operate without compromising safety.

Cost Impact

    There are approximately 700 Model DC-9-10, -20, -30, -40, and -50 
series airplanes, and C-9 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 397 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 5 work hours per airplane to accomplish 
the proposed inspections, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the proposed AD on 
U.S. operators is estimated to be $119,100, or $300 per airplane, per 
inspection cycle.
    For certain airplanes, it would take approximately between 21 and 
26 work hours per airplane depending on the airplane configuration to 
accomplish the proposed modification specified in McDonnell Douglas DC-
9 Service Bulletin 53-165, Revision 3, dated May 3, 1989, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately between $3,470 and $11,831 per airplane, depending on the 
airplane configuration. Based on these figures, the cost impact of this 
proposed modification AD on U.S. operators is estimated to be between 
$4,730, or $13,391 per airplane.
    For certain airplanes, it would take approximately 9 work hours per 
airplane to accomplish the proposed modification specified in McDonnell 
Douglas DC-9 Service Bulletin 53-157, Revision 1, dated January 7, 
1985, at an average labor rate of $60 per work hour. Based on these 
figures, the cost impact of this proposed modification AD on U.S. 
operators is estimated to be $540 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 proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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.

[[Page 48387]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

McDonnell Douglas: Docket 2000-NM-324-AD.

    Applicability: Model DC-9-10, -20, -30, -40, and -50 series 
airplanes, and C-9 airplanes, equipped with a floor level hinged 
(ventral) door of the aft pressure bulkhead; as listed in McDonnell 
Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 
2001; certificated in any category; except for those airplanes on 
which the modification required by paragraph (d) or (e) of AD 96-10-
11, amendment 39-9618, or paragraph K. of AD 85-01-02 R1, amendment 
39-5241, has been done.

    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 (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 detect and correct fatigue cracks in the corners and upper 
center of the door cutout of the aft pressure bulkhead, which could 
result in rapid decompression of the fuselage and consequent reduced 
structural integrity of the airplane, accomplish the following:

Visual and X-Ray Inspection

    (a) Except as provided by paragraph (h) of this AD, prior to the 
accumulation of 15,000 total landings, or within 4,000 landings 
after the effective date of this AD, whichever occurs later, do a 
general visual and x-ray inspection to detect cracks of the upper 
and lower corners and upper center of the door cutout of the aft 
pressure bulkhead, per McDonnell Douglas Service Bulletin DC9-53-
137, Revision 07, dated February 6, 2001.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or drop-light, and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

No Crack Detected: Repetitive Inspections

    (b) If no crack is detected during any inspection required by 
paragraph (a) of this AD, within 8,000 landings after accomplishment 
of the general visual and x-ray inspections required by paragraph 
(a) of this AD, do a general visual inspection and eddy current 
inspection of the upper and lower corners and upper center of the 
door cutout of the aft pressure bulkhead door, per McDonnell Douglas 
Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001. 
Repeat the general visual and eddy current inspections required by 
this paragraph every 8,000 landings.

Any Crack Detected: Corrective Actions and Repetitive Inspections

    (c) If any crack is detected during any inspection required by 
paragraph (a) or (b) of this AD, do the actions specified in 
paragraphs (c)(1) and (c)(2) of this AD per McDonnell Douglas 
Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001.
    (1) Before further flight, do the applicable corrective actions 
(i.e., modification of the bulkhead; trim forward facing flange; 
stop drill ends of cracks; install repair kit; replacement of 
cracked part with new parts; and install additional doublers) 
identified in Conditions I through XLIII inclusive, excluding 
Conditions XXI, XXXVII, and XXXVIII (not used at this time), of the 
Accomplishment Instructions of the service bulletin; and
    (2) At the times specified in the Accomplishment Instructions of 
the service bulletin, do the applicable repetitive inspections, 
until the action specified in paragraph (d) or (g) of this AD has 
been done.

Concurrent Requirements

    (d) Except as provided by paragraph (h) of this AD, modify the 
ventral aft pressure bulkhead structure by accomplishing all actions 
specified in Accomplishment Instructions of McDonnell Douglas DC-9 
Service Bulletin 53-165, Revision 3, dated May 3, 1989, per the 
service bulletin; at the applicable time specified in paragraph 
(d)(1), (d)(2), or (d)(3) of this AD.

    Note 3: Modification before the effective date of this AD per 
McDonnell Douglas DC-9 Service Bulletin 53-165, dated January 31, 
1983; Revision 1, dated February 20, 1984; or Revision 2, dated 
August 29, 1986; is considered acceptable for compliance with the 
requirements of paragraph (d) of this AD.

    (1) For airplanes on which the bulkhead modification specified 
in McDonnell Douglas DC-9 Service Bulletin 53-139, dated September 
26, 1980, or Revision 1, dated April 30, 1981, has been done, except 
as provided by paragraph (d)(3) of this AD: Modify within 15,000 
landings after accomplishment of the bulkhead modification, or 
within 4,000 landings after the effective date of this AD, whichever 
occurs later. Accomplishment of this modification constitutes 
terminating action for the repetitive inspection requirements of 
paragraphs (b) and (c)(2) of this AD.
    (2) For airplanes on which the production equivalent of the 
modification specified in paragraph (d)(1) of this AD has been done 
before delivery, except as provided by paragraph (d)(3) of this AD: 
Modify before the accumulation of 15,000 total landings, or within 
4,000 landings after the effective date of this AD, whichever occurs 
later.
    (3) For airplanes listed in McDonnell Douglas DC-9 Service 
Bulletin 53-165, Revision 3, dated May 3, 1989, that are specified 
in paragraph (e) of this AD: Modify in conjunction with the 
requirements of paragraph (e) of this AD, or within 18 months after 
accomplishment of requirements of paragraph (e) of this AD.
    (e) For Model DC-9-30 and -50 series airplanes and C-9 
airplanes, as listed in McDonnell Douglas DC-9 Service Bulletin 53-
157, Revision 1, dated January 7, 1985: Within 18 months after the 
effective date of this AD, modify the ventral aft pressure bulkhead 
per the service bulletin.

    Note 4: Modification before the effective date of this AD per 
McDonnell Douglas DC-9 Service Bulletin 53-157, dated August 11, 
1981, is considered acceptable for compliance with the requirements 
of paragraph (e) of this AD.

Compliance With AD 85-01-02 R1

    (f) Accomplishment of the visual and x-ray inspections required 
by paragraph (a) of this AD constitutes terminating action for the 
repetitive inspection requirements of AD 85-01-02 R1.

Terminating Modification

    (g) Accomplishment of the modification (reference McDonnell 
Douglas DC-9 Service Bulletin 53-166) required by paragraph (d) or 
(e) of AD 96-10-11, amendment 39-9618 (61 FR 24675, May 16, 1996) 
(which references ``DC-9/MD-80 Aging Aircraft Service Action 
Requirements Document'' (SARD), McDonnell Douglas Report No. MDC 
K1572, Revision A, dated June 1, 1990, as the appropriate source of 
service information for accomplishing the modification) terminates 
the repetitive inspection requirements of paragraphs (b) and (c) of 
this AD.

Exception to Inspections and Modifications

    (h) The inspections and modifications required by this AD do NOT 
need to be done if, after the effective date of this AD, the 
airplane is operated without cabin pressurization and a placard is 
installed in the cockpit in full view of the pilot that states the 
following:

``OPERATION WITH CABIN PRESSURIZATION IS PROHIBITED.''

Alternative Methods of Compliance

    (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, Los Angeles Aircraft Certification 
Office (ACO), FAA. 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.

Special Flight Permit

    (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.


[[Page 48388]]


    Issued in Renton, Washington, on September 14, 2001.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-23417 Filed 9-19-01; 8:45 am]
BILLING CODE 4910-13-P