[Federal Register Volume 68, Number 73 (Wednesday, April 16, 2003)]
[Proposed Rules]
[Pages 18567-18569]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-9302]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-184-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-8-11, DC-8-
12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and DC-8-43 
Airplanes; Model DC-8-50 Series Airplanes; Model DC-8F-54 and DC-8F-55 
Airplanes; Model DC-8-60 Series Airplanes; Model DC-8-70 Series 
Airplanes; and Model DC-8-70F 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 certain McDonnell Douglas 
airplanes. This proposal would require an inspection to determine the 
material composition of the auxiliary spar cap of the lower inboard of 
the left and right wings. For certain airplanes, this proposal also 
would require repetitive detailed and dye penetrant inspections for 
cracking of the spar cap, and corrective actions if necessary. This 
action is necessary to detect and correct stress corrosion cracking of 
the auxiliary spar cap, which could cause excessive loads to the 
structure attaching the support fitting of the main landing gear (MLG) 
to the wing, and result in loss of the MLG. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by June 2, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-184-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 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. 2001-NM-184-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 FAA, or at the Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Jon Mowery, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5322; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.

[[Page 18568]]

    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 2001-NM-184-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. 2001-NM-184-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received numerous reports indicating that cracking has 
occurred in the auxiliary spar cap of the lower inboard near the 
outboard attach bolts on various McDonnell Douglas Model DC-8 
airplanes. The cracking occurred on airplanes that have accumulated 
more than 36,000 total flight hours. Investigation indicates that the 
cracking appeared to be due to stress corrosion. Such cracking of the 
auxiliary spar cap, if not detected and corrected, could cause 
excessive loads on the structure attaching the support fitting of the 
main landing gear (MLG) to the wing, and result in loss of the MLG.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas DC-8 Service 
Bulletin 57-85, Revision 1, dated July 5, 1991. That service bulletin 
describes procedures for performing repetitive detailed and dye 
penetrant inspections to detect stress cracking of the auxiliary spar 
cap of the lower inboard of the left and right wings. For cracking that 
is within certain limits, the service bulletin describes corrective 
actions such as repair or rework and application of corrosion-
inhibiting compound, if necessary. For any cracking that is outside the 
limits specified in the service bulletin, the service bulletin 
describes procedures for replacing the auxiliary spar cap with either a 
new spar cap made with 7075-T6 aluminum or with a new, improved spar 
cap made with 7075-T73 aluminum. Additionally, for any cracking that is 
detected at the bathtub end of both forward and aft bolt holes, the 
service bulletin describes procedures for replacement of those MLG 
fittings with new or serviceable fittings. 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 an inspection to determine the material 
composition of the auxiliary spar cap. If the spar cap is made of 7075-
T6 aluminum, the proposed AD would require accomplishment of the 
actions and procedures specified in the service bulletin described 
above for the repetitive inspections for cracking, and repair, rework, 
and replacement of the spar cap if necessary.
    Operators should note that the FAA has received information 
indicating that there may be a parts availability problem in procuring 
spar caps made of 7075-T73 aluminum. However, we have determined that 
the repetitive inspections proposed by this AD can be allowed to 
continue in lieu of accomplishment of the terminating action 
(replacement of both spar caps with caps made of 7075-T73 aluminum). In 
making this determination, we consider that, in this case, long-term 
continued operational safety will be adequately assured by 
accomplishing the repetitive inspections to detect cracking of the 
auxiliary spar cap before it represents a hazard to the airplane.

Differences Between This NPRM and the Service Information

    The FAA considers that, prior to performing the inspections and 
corrective actions described in the service bulletin above, it is 
necessary to perform an inspection to determine the material 
composition of the auxiliary spar cap of the lower inboard of the left 
and right wings. That inspection may be done per a method approved by 
the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, or 
by performing an eddy current test of the auxiliary spar cap per the 
Non-Destructive Testing Standard Practice Manual MDC-93K0393 (NDTSPM) 
06-10-01.006. If the auxiliary spar cap is composed of 7075-T6 
aluminum, this proposed AD would require accomplishment of the actions 
specified in the service bulletin described above, as applicable.
    Additionally, operators should note that, although the service 
bulletin specifies that the manufacturer may be contacted for 
disposition of certain cracking outside the limits specified in the 
service bulletin, this proposal would require the disposition of any 
such cracking that was detected to be accomplished per a method 
approved by the FAA.

Cost Impact

    There are approximately 264 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 244 airplanes of U.S. registry 
would be affected by this proposed AD. We estimate that it would take 
approximately 2 work hours per airplane to accomplish the proposed 
inspection to determine the material of the spar cap. We estimate 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 
$29,280, or $120 per airplane, per inspection cycle.
    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 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

[[Page 18569]]

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 2001-NM-184-AD.

    Applicability: Model DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-
32, DC-8-33, DC-8-41, DC-8-42, and DC-8-43 airplanes; Model DC-8-51, 
DC-8-52, DC-8-53, and DC-8-55 airplanes; Model DC-8F-54 and DC-8F-55 
airplanes; Model DC-8-61, DC-8-62, and DC-8-63 airplanes; Model DC-
8-61F, DC-8-62F, and DC-8-63F airplanes; Model DC-8-71, DC-8-72, and 
DC-8-73 airplanes; as listed in McDonnell Douglas DC-8 Service 
Bulletin 57-85, Revision 1, dated July 5, 1991; 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 (c) 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 cracking of the auxiliary spar cap, which 
could cause excessive loads to the structure attaching the support 
fitting of the main landing gear (MLG) to the wing, and result in 
loss of the MLG; accomplish the following:

Inspection To Determine the Material of the Auxiliary Spar Cap

    (a) Within 24 months or 2,000 flight cycles after the effective 
date of this AD, whichever occurs later, inspect to determine the 
material composition of the auxiliary spar cap (Part Numbers 
5615058-1 through -506 inclusive) of the lower inboard of the left 
and right wings, in accordance with a method approved by the 
Manager, Los Angeles Aircraft Certification Office (ACO), FAA, or by 
performing an eddy current test of the auxiliary spar cap per the 
Non-Destructive Testing Standard Practice Manual MDC-93K0393 
(NDTSPM) 06-10-01.006. If the material of the spar cap is 7075-T73 
aluminum, no further action is required by this paragraph.

Inspections for Cracking and Follow-on Corrective Actions

    (b) If the material of the auxiliary spar cap found during the 
inspection required by paragraph (a) of this AD is 7075-T6 aluminum: 
Within 2 years or 2,000 flight cycles after accomplishing the 
inspection required by paragraph (a) of this AD, perform a detailed 
inspection and a dye penetrant inspection for cracking of the 
auxiliary spar cap and the bathtub end of either the forward or the 
aft bolt hole of the lower inboard of the left and right wings, as 
applicable, per McDonnell Douglas DC-8 Service Bulletin 57-85, 
Revision 1, dated July 5, 1991.

    Note 2: For the purposes of this AD, a detailed 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.''

    (1) If no cracking is detected, repeat the inspection at 
intervals not to exceed 6,400 flight hours, until the auxiliary spar 
cap is replaced with a spar cap made with 7075-T73 aluminum, in 
accordance with the service bulletin.
    (2) If any cracking of the auxiliary spar cap or at the bathtub 
end of either the forward or the aft bolt hole is detected that is 
within the limits specified in the service bulletin, before further 
flight, rework or repair the spar cap, as applicable, and apply 
corrosion inhibiting compound, in accordance with the service 
bulletin. Repeat the inspection for cracking at intervals not to 
exceed 1,600 flight hours, until the auxiliary spar cap is replaced 
with a spar cap composed of 7075-T73 aluminum. Replacement of both 
spar caps with 7075-T73 aluminum is terminating action for the 
requirements of this AD.
    (3) If any cracking at the bathtub end of both the forward and 
aft bolt holes is detected that is within the limits specified in 
the service bulletin, before further flight, replace the MLG fitting 
with a new or serviceable fitting, in accordance with the service 
bulletin.
    (4) If any cracking of the auxiliary spar cap is detected that 
is outside the limits specified in the service bulletin, before 
further flight, replace the auxiliary spar cap with a cap composed 
of 7075-T73 aluminum, in accordance with the service bulletin, or by 
a method approved by the Manager, Los Angeles Aircraft Certification 
Office (ACO), FAA. For a repair method to be approved by the 
Manager, Los Angeles ACO, as required by this paragraph, the 
Manager's approval letter must specifically reference this AD.

Alternative Methods of Compliance

    (c) 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, 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, FAA.

    Note 3: 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 Permits

    (d) Special flight permits may be issued in accordance with 
Sec. Sec.  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 April 8, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-9302 Filed 4-15-03; 8:45 am]
BILLING CODE 4910-13-P