[Federal Register Volume 61, Number 13 (Friday, January 19, 1996)]
[Proposed Rules]
[Pages 1301-1303]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-491]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-145-AD]


Airworthiness Directives; McDonnell Douglas DC-9 Series 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 all McDonnell Douglas Model DC-9 
series airplanes. This proposal would require inspection(s) to detect 
cracking in the nose skin of the fuselage, and various follow-on 
actions. The proposal would also provide an optional modification, 
which would defer certain repetitive inspections, if no cracking is 
detected. This proposal is prompted by reports of cracking in the upper 
nose skin of the fuselage due to fatigue. The actions specified by the 
proposed AD are intended to prevent fatigue-related cracking, which 
could compromise the structural integrity of the airplane.

DATES: Comments must be received by March 12, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-145-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: Ron Atmur, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(310) 627-5224; fax (310) 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 

[[Page 1302]]
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 95-NM-145-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. 95-NM-145-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 20, 1994, the FAA issued AD 94-03-01, amendment 39-8807 
(59 FR 6538, February 11, 1994), which is applicable to McDonnell 
Douglas DC-9 series airplanes and C-9 (military) airplanes. That AD 
requires implementation of a program of structural inspections to 
detect and correct fatigue cracking in order to ensure the continued 
airworthiness of these airplanes as they approach the manufacturer's 
original fatigue design life goal. AD 94-03-01 includes a requirement 
to inspect the upper nose skin of the fuselage under the fleet leader 
operator sampling criteria. McDonnell Douglas Report No. L26-008, ``DC-
9 Supplemental Inspection Document (SID),'' which is referenced in that 
AD as the appropriate source of service information, designates this 
area of the airplane as Principal Structural Element (PSE) 53.09.29 
(left side) and 53.09.30 (right side). The fatigue life threshold 
(Nth) for the upper nose skin is 113,592 total landings. The 
sampling period for this PSE started in August 1988, and will end on 
March 19, 1998. Sampling inspections are to be performed on airplanes 
in the candidate fleet that have accumulated more than 56,796 total 
landings (which is Nth/2).
    Since issuance of that AD, the FAA has received reports of cracking 
in the upper nose skin of the fuselage on Model DC-9 series airplanes. 
A preload condition was discovered on some of these airplanes. These 
airplanes had accumulated between 47,000 and 92,000 total landings. 
Investigation revealed that the cause of such cracking has been 
attributed to fatigue. Fatigue-related cracking, if not detected and 
corrected in a timely manner, could compromise the structural integrity 
of the airplane.
    The FAA has reviewed and approved McDonnell Douglas DC-9 Service 
Bulletin 53-262, dated October 11, 1994, which describes the following 
procedures:
    1. High frequency eddy current (HFEC) inspection(s) to detect 
cracking in the nose skin of the fuselage;
    2. An optional modification of the upper nose skin of the cockpit 
fuselage, if no cracking is detected, which would defer the repetitive 
inspections; and
    3. Repair of the cracked nose skin, if any cracking is detected 
within the repair limits.
    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 HFEC inspection(s) to detect cracking in the 
nose skin of the fuselage. All airplanes would be required to be 
inspected initially prior to the accumulation of 40,000 total landings 
or within 3,000 landings after the effective date of the final rule, 
whichever occurs later. If no cracking is detected as a result of this 
inspection, operators may either:
    1. Repeat the inspection at intervals not to exceed 4,000 landings; 
or
    2. Install a modification of the upper nose skin of the cockpit 
fuselage, after which a visual inspection to detect cracking would be 
required prior to the accumulation of 60,000 landings after the 
accomplishment of the modification. The visual inspection would be 
repeated at intervals not to exceed 25,000 landings.
    If any cracking is detected as a result of the initial HFEC 
inspection and the cracking is within certain repair limits, the 
cracking must be repaired and the repair visually inspected prior to 
the accumulation of 60,000 landings since accomplishment of the repair, 
in accordance with a method approved by the FAA.
    If any cracking is detected a a result of the initial HFEC 
inspection and the cracking is outside of certain repair limits, the 
crack must be repaired in accordance with a method approved by the FAA.
    The HFEC inspections, certain repairs, and modification procedures 
would be required to be accomplished in accordance with the service 
bulletin described previously.
    There are approximately 889 Model DC-9 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 568 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 10 work hours per airplane to accomplish 
the proposed actions, 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 $340,800, or $600 per airplane, per 
inspection.
    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 AD were not adopted.
    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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

McDonnell Douglas: Docket 95-NM-145-AD.


[[Page 1303]]

    Applicability: All Model DC-9-10, -20, -30, -40, -50, and C-9 
(military) series airplanes, 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 (b) 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-related cracking, which could compromise the 
structural integrity of the airplane, accomplish the following:
    (a) Prior to the accumulation of 40,000 total landings, or 
within 3,000 landings after the effective date of this AD, whichever 
occurs later, perform a high frequency eddy current (HFEC) 
inspection to detect cracking in the nose skin of the fuselage, in 
accordance with McDonnell Douglas DC-9 Service Bulletin 53-262, 
dated October 11, 1994.
    (1) If no cracking is detected, accomplish either paragraph 
(a)(1)(i) or (a)(1)(ii) of this AD, in accordance with the service 
bulletin.
    (i) Repeat the HFEC inspection thereafter at intervals not to 
exceed 4,000 landings; or
    (ii) Accomplish the modification of the upper nose skin of the 
cockpit fuselage in accordance with the service bulletin. Prior to 
the accumulation of 60,000 landings after accomplishment of this 
modification, perform a visual inspection of the upper nose skin of 
the cockpit fuselage in accordance with the service bulletin. Repeat 
the visual inspection thereafter at intervals not to exceed 25,000 
landings.
    (2) If any cracking is detected and it is within the repair 
limits specified in the service bulletin, prior to further flight, 
repair the cracked nose skin in accordance with the service 
bulletin. Prior to the accumulation of 60,000 landings after 
accomplishment of this repair, perform a visual inspection to detect 
cracking of the repair; and prior to further flight, repair any 
cracking found during this inspection; in accordance with a method 
approved by the Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, Transport Airplane Directorate.
    (3) If any cracking is detected and it is beyond the repair 
limits specified in the service bulletin, prior to further flight, 
repair the cracked nose skin in accordance with a method approved by 
the Manager, Los Angeles ACO.
    (b) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (c) 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 January 10, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-491 Filed 1-18-96; 8:45 am]
BILLING CODE 4910-13-U