[Federal Register Volume 65, Number 181 (Monday, September 18, 2000)]
[Proposed Rules]
[Pages 56270-56273]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-23852]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-57-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, among other actions, various 
inspections to detect cracks of the cockpit enclosure window sill, and 
follow-on and corrective actions, as applicable. This action is 
necessary to prevent fatigue cracking of the internal doublers and 
frame structure of the fuselage skin of the cockpit enclosure window 
sill. This action is intended to address the identified unsafe 
condition.

[[Page 56271]]


DATES: Comments must be received by November 2, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-57-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-57-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: 
Technical Publications Business Administration, Dept. C1-L51 (2-60). 
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; 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.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-57-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-57-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports of cracking of the internal 
doublers and frame structure of the fuselage skin of the cockpit 
enclosure window sill on McDonnell Douglas Model DC-9 series airplanes. 
These airplanes had accumulated between 61,624 and 100,238 total flight 
cycles. The cause of such cracking has been attributed to high-cycle 
fatigue. Fatigue cracking of the subject area, if not corrected, 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 DC9-53-290, dated December 14, 1999. The service bulletin 
describes the following procedures:
     A general visual inspection to determine if a particular 
type of repair that has been installed;
     A general visual inspection to detect loose or missing 
fasteners or cracks of the upper nose skins of the cockpit;
     A magnetic particle inspection to detect cracks of the 
zees; and
     A detailed visual, borescope, and high frequency eddy 
current (HFEC) inspection to detect cracks of the skins, frames, beams, 
and angles. The service bulletin also describes the following follow-on 
and corrective actions, as applicable, that include:
     A permanent repair (including visual and magnetic particle 
inspections, and replacement/rework);
     Inspections to detect cracks of the completed repair; and 
repair, if necessary;
     A temporary repair; and follow-on inspections to detect 
cracks of the internal structure and external doublers; and
     Replacement of any cracked zee with a new part.
    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 proposal would require the repair of those 
conditions to be accomplished in accordance with a method approved by 
the FAA.

Cost Impact

    There are approximately 809 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 572 airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 7 work hours per airplane to accomplish the proposed 
inspections, and that the average labor rate is $60 per work hour. 
Based on these figures, the cost impact of the proposed AD on U.S. 
operators is estimated to be $240,240, or $420 per airplane.
    The cost impact figure discussed above is 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

[[Page 56272]]

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.


Sec. 39.13  [Amended]

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

McDonnell Douglas: Docket 2000-NM-57-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 DC9-53-290, December 14, 1999; 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 (k) 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 fatigue cracking of the internal doublers and frame 
structure of the fuselage skin of the cockpit enclosure window sill, 
accomplish the following:

    Note 2: Where there are differences between the AD and the 
referenced service bulletin, the AD prevails.

Various Inspections

    (a) Before the accumulation of 40,000 total landings, or within 
5,000 landings after the effective date of this AD, whichever occurs 
later, do the actions specified in (a)(1), (a)(2), (a)(3), and 
(a)(4) of this AD per paragraph 3., ``Accomplishment Instructions,'' 
of McDonnell Douglas Service Bulletin DC9-53-290, dated December 14, 
1999.
    (1) Do a general visual inspection to determine if any repair 
identified in paragraphs 3.A.6. and 3.A.8. of the Accomplishment 
Instructions of the service bulletin has been accomplished prior to 
the effective date of this AD. AND
    (2) Do a general visual inspection to detect cracks of the upper 
nose skins of the cockpit. AND
    (3) Do a magnetic particle inspection to detect cracks of the 
zees. AND
    (4) Do a detailed visual, borescope, and high frequency eddy 
current (HFEC) inspection to detect cracks of the skins, frames, 
beams, and angles.

    Note 3: 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.''


    Note 4: 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.''

Condition 1 (No Crack and No Previous Repair)

    (b) If no crack and no previous repair is detected during any 
inspection required by paragraphs (a)(1) through (a)(4) of this AD, 
do the actions specified in paragraph (b)(1) of this AD, or in 
paragraphs (b)(2) and (b)(3) of this AD, at the times specified in 
those paragraphs.
    (1) Repeat the inspections required by paragraphs (a)(2), 
(a)(3), and (a)(4) of this AD thereafter every 5,000 landings.
    (2) Before further flight, do the permanent repair (including 
visual and magnetic particle inspections, and replacement/rework) 
specified in Condition 1, Option 2 of the Accomplishment 
Instructions of McDonnell Douglas Service Bulletin DC9-53-290, dated 
December 14, 1999. Accomplishment of the permanent repair stops the 
repetitive inspections required by paragraph (b)(1) of this AD.
    (3) Within 40,000 landings after doing the permanent repair 
required by paragraph (b)(2) of this AD, do the inspections 
specified in paragraphs (a)(2), (a)(3), and (a)(4) of this AD to 
detect cracks of the completed repair, per McDonnell Douglas Service 
Bulletin DC9-53-290, dated December 14, 1999.
    (i) I no crack is detected, repeat the inspections specified in 
paragraph (b)(3) of this AD thereafter every 5,000 landings.
    (ii) If any crack is detected, before further flight, repair per 
a method approved by the Manager, Los Angeles Aircraft Certification 
Office (ACO), FAA.

Condition 2 (Any Crack Within Limits)

    (c) If any crack is detected during any inspection required by 
paragraphs (a)(2) through (a)(4) of this Ad, and that crack is 
WITHIN the limits specified in Condition 2 of the Accomplishment 
Instructions of McDonnell Douglas Service Bulletin DC9-53-290, dated 
December 14, 1999, do the actions specified in paragraphs (c)(1) 
through (c)(4) of this AD, or in paragraphs (b)(2) and (b)(3) of 
this AD; at the times specified in those paragraphs. The actions 
required by paragraphs (c)(1) through (c)(3) of this AD must be done 
per the Accomplishment Instructions of McDonnell Douglas Service 
Bulletin DC9-53-290, dated December 14, 1999.
    (1) Before further flight, do the temporary repair per Condition 
2, Option 1 of the Accomplishment Instructions of the service 
bulletin.
    (2) Within 2,000 landings after doing the temporary repair, do a 
general visual

[[Page 56273]]

inspection to detect cracks of the external doublers.
    (3) Within 3,500 landings after doing the temporary repair, do 
borescope and HFEC inspections to detect cracks of the internal 
structure.
    (4) Within 8,000 landings after doing the temporary repair, do 
the action specified in paragraphs (b)(2) of this AD; and at the 
time specified in paragraph (b)(3) of this AD, do the actions 
specified in that paragraph.
    (d) If no crack is detected during any general visual inspection 
required by paragraph (c)(2) of this AD, repeat the general visual 
inspection thereafter every 2,000 landings.
    (e) If no crack is detected during any borescope or HFEC 
inspection required by paragraph (c)(3) of this AD, repeat the 
borescope and HFEC inspections thereafter every 3,500 landings.
    (f) If any crack is detected during any inspection required by 
paragraph (c)(2) or (c)(3) of this AD, at the times specified in 
paragraphs (b)(2) and (b)(3) of this AD, do the actions specified in 
those paragraphs.

Condition 3 (Existing Repairs Accomplished Per Certain Service 
Information)

    (g) If any repair is detected during any inspection required by 
paragraph (a)(1) of this AD, and that repair has been accomplished 
previously in accordance with the service information identified in 
Condition 3 of the Accomplishment Instructions of McDonnell Douglas 
Service Bulletin DC9-53-290, dated December 14, 1999, do the actions 
specified in paragraph (g)(1) of this AD, or in paragraphs (g)(2) 
and (g)(3) of this AD, at the times specified in those paragraphs.
    (1) At the times specified in paragraphs (c)(2) and (c)(3) of 
this AD, do the actions specified in those paragraphs; and at the 
time specified in paragraphs (d), (e), and (f) of this AD, do the 
applicable follow-on or corrective actions specified in those 
paragraphs.
    (2) Within 8,000 landings after doing the temporary repair, do 
the action specified in paragraph (b)(2).
    (3) Within 40,000 landings after doing the permanent repair, do 
the actions specified in paragraph (b)(3) of this AD.

Condition 4 (Existing Repairs Not Accomplished Per Certain Service 
Information)

    (h) If any repair is detected during any inspection required by 
paragraph (a)(1) of this AD, and the repair has not been 
accomplished previously in accordance with the service information 
identified in Condition 3 of the Accomplishment Instructions of 
McDonnell Douglas Service Bulletin DC9-53-290, dated December 14, 
1999, before further flight, repair per a method approved by the 
Manager, Los Angeles ACO.

Condition 5 (Any Crack Outside Limits)

    (i) If any crack is detected during any inspection required by 
paragraphs (a)(2) through (a)(4) of this AD, and that crack is 
OUTSIDE the limits specified in Condition 2 of the Accomplishment 
Instructions of McDonnell Douglas Service Bulletin DC9-53-290, dated 
December 14, 1999, at the times specified in paragraphs (b)(2) and 
(b)(3) of this AD, do the actions specified in paragraphs (b)(2) and 
(b)(3) of this AD.

Corrective Action for Cracked Zee

    (j) If any cracked zee is detected during any inspection 
required by paragraph (a)(3) of this AD, before further flight, 
replace the cracked zee with a new part per McDonnell Douglas 
Service Bulletin DC9-53-290, dated December 14, 1999.

Alternative Methods of Compliance

    (k) 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 ACO. 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

    (l) 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 September 12, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-23852 Filed 9-15-00; 8:45 am]
BILLING CODE 4910-13-U