[Federal Register Volume 68, Number 245 (Monday, December 22, 2003)]
[Proposed Rules]
[Pages 71040-71045]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-31440]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-255-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, 
DC-9-20, DC-9-30, DC-9-40, and DC-9-50 series airplanes, and C-9 
(military) airplanes, that would have superseded an existing AD that 
currently requires repetitive ultrasonic or magnetic particle 
inspections to detect cracking of the engine pylon aft upper spar 
straps (caps); and if necessary, replacement of the strap with a new 
strap, or modification of the engine pylon rear spar straps, which 
constitutes terminating action for the repetitive inspections. The 
proposed AD also would have required new, improved repetitive 
ultrasonic inspections, and corrective actions if necessary. The 
proposed AD also would have required, among other items, a terminating 
action for the repetitive inspection requirements. This new action 
revises the proposed rule by adding airplanes to the applicability. The 
actions specified by this new proposed AD are intended to detect and 
correct such fatigue cracking, which could result in major damage to 
the adjacent structure of the pylon aft upper spar cap, and consequent 
reduced structural integrity of the airplane. This action is intended 
to address the identified unsafe condition.

DATES: Comments must be received by January 16, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-255-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. 99-NM-255-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 or 2000 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 90712-4137; 
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 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.
    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 99-NM-255-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. 99-NM-255-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain McDonnell Douglas Model DC-9-10, DC-9-20, DC-9-30, DC-9-40, and 
DC-9-50 series airplanes, and C-9 (military) airplanes, was published 
as a notice of proposed rulemaking (NPRM) in the Federal Register on 
May 10, 2000 (65 FR 30025). That NPRM proposed to supersede AD 78-01-
16, amendment 39-3117 (43 FR 1300, January 9, 1978), which is 
applicable to certain McDonnell Douglas Model DC-9-10, DC-9-20, DC-9-
30, DC-9-40, and DC-9-50 series airplanes, and C-9 (military) 
airplanes. That NPRM would have continued to require repetitive 
ultrasonic or magnetic particle inspections to detect cracking of the

[[Page 71041]]

engine pylon aft upper spar straps (caps); and if necessary, 
replacement of the strap with a new strap, or modification of the 
engine pylon rear spar straps, which constitutes terminating action for 
the repetitive inspections. That NPRM would have added new, improved 
repetitive ultrasonic inspections, and corrective actions, if 
necessary. That NPRM also would have required, among other items, a 
terminating action for the repetitive inspection requirements. That 
NPRM was prompted by additional reports of fatigue cracking in the 
subject area of these airplanes. Such fatigue cracking, if not 
corrected, could result in major damage to the adjacent structure of 
the pylon aft spar upper cap, and consequent reduced structural 
integrity of the airplane.

Actions Since Issuance of Previous Proposal

    Since the issuance of that NPRM, the manufacturer has advised the 
FAA that the identified unsafe condition may also occur on additional 
airplanes with a certain configuration of the left and right pylon aft 
upper caps.

Explanation of New Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
(ASB) DC9-54A031, Revision 09, dated September 3, 2002. That ASB 
describes procedures for new repetitive ultrasonic or magnetic particle 
inspections of the engine pylon aft upper spar straps (caps) to detect 
cracking; and corrective actions if necessary. The corrective actions 
include reapplication of a sealant; modification of the rear spar upper 
strap (cap); and replacement of the bearing of the spar strap (cap) 
with a new annular groove bearing if necessary. Revision 09 contains 
information that is essentially the same as Revision 08, which was 
referenced in the previous NPRM as one of the applicable sources of 
service information. However, Revision 09 specifically references 
Boeing Service Bulletin DC9-54-031, Revision 05, dated April 25, 2003, 
as an additional source of service information.
    We have also reviewed and approved Boeing Service Bulletin DC9-54-
031, Revision 05, dated April 25, 2003. The service bulletin describes 
procedures for modification of the rear spar upper strap (cap), which 
would eliminate the need for the repetitive inspections specified in 
Boeing ASB DC9-54A031, Revision 09, dated September 3, 2002, discussed 
above. The modification includes installation of access doors on the 
pylon rear spars, if applicable; replacement of the strap on the pylon 
upper rear spar cap with a new strap having an annular groove bearing 
installed using new close tolerance attaching parts; and modification 
of the pylon-to-vibration isolator link. That service bulletin also 
adds airplanes to the effectivity of the service bulletin.
    Accomplishment of the actions specified in the service bulletins 
described above is intended to adequately address the identified unsafe 
condition.

Comments Received

    Due consideration has been given to the comments received in 
response to the NPRM:

Request To Revise and Update Service Information

    One commenter requests that Revision 4 of ``McDonnell Douglas 
Service Bulletin 54-031'' be revised to specify the bearing part number 
(P/N) in conjunction with the pylon spar strap P/N.
    Since the issuance of the original NPRM, we have reviewed and 
approved Revision 05, dated April 25, 2003, of Boeing Service Bulletin 
DC9-54-031, which specifies the bearing P/N. We have referenced 
Revision 05 of that service bulletin in this supplemental NPRM as a 
source of service information.

Request for Clarification of Terminating Action

    One commenter, an airline operator, states that multiple paragraphs 
in the original NPRM specify that modification per Revision 4 of 
``McDonnell Douglas Service Bulletin 54-031'' constitutes terminating 
action of the repetitive requirements of the AD. The commenter notes, 
however, that AD 78-01-16, amendment 39-3117, requires replacement of 
the pylon strap with a heavy gauge lug and does not require use of the 
annular groove bearing. The commenter states that this contradicts 
Revision 4 of the service bulletin and paragraph (m) of the original 
NPRM, which specify installation of the annular groove bearing. The 
commenter requests clarification.
    We acknowledge that clarification is necessary. We are aware that 
some operators of the subject airplanes have accomplished the actions 
specified in Revision 4 of McDonnell Douglas DC-9 Service Bulletin 54-
31 or have had production equivalent installations of the spar strap 
(cap) with a pin-staked bearing. For those airplanes having a spar 
strap (cap) with a pin-staked bearing, paragraph (l) of this 
supplemental NPRM would require inspections for cracking, and 
modification if necessary, per Revision 05 of Boeing Service Bulletin 
DC9-54-031, dated April 25, 2003.

Request To Clarify Modification as a Terminating Action

    That same commenter requests clarification of whether 
accomplishment of the modification using a pin-staked bearing, as 
described in Revision 4 of McDonnell Douglas DC-9 Service Bulletin 54-
31, requires re-implementation of inspections of pylon straps until 
such time as the annular groove bearing is installed.
    We agree that clarification is needed. As explained in the previous 
comment section, those airplanes having a spar strap (cap) with a pin-
staked bearing would require inspections for cracking, and modification 
if necessary, in accordance with Revision 05 of Boeing Service Bulletin 
DC9-54-031, dated April 25, 2003. We have revised paragraph (l) of this 
supplemental NPRM to specify that the actions are to be accomplished 
per Revision 05, which describes installation of the annular groove 
bearing.

Request To Clarify Compliance Times for the Modification

    Another commenter, also an airline operator, notes that paragraph 
(h) of the NPRM specifies compliance times for airplanes that have not 
had the modification to the spar cap accomplished and that have not had 
the spar cap replaced. The commenter further notes that paragraph (i) 
of the NPRM specifies compliance times for aircraft that have not had 
the modification of the spar cap accomplished but have had the spar cap 
replaced. The commenter points out that neither of those configurations 
apply to its fleet, since the spar cap has been modified on its fleet. 
The commenter assumes that if the spar caps have been previously 
modified, the NPRM would not be applicable to those airplanes. The 
commenter states that the reader of the NPRM should not have to make an 
assumption regarding applicability, and requests that the FAA clarify 
that the modified spar caps are not subject to the requirements of the 
NPRM.
    We agree that clarification is needed. Paragraph (l) of this 
supplemental NPRM would require that, for airplanes (specified in 
Revision 05 of DC-9 Service Bulletin 54-031 as ``Group 12'' airplanes) 
on which the spar strap (cap) with a pin staked bearing per DC-9 
Service Bulletin 54-31 has been installed or that have a production 
equivalent installed, it is necessary to

[[Page 71042]]

perform an inspection of the pylon upper rear spar strap (cap) for 
bearing migration and correct staking and follow-on modification, if 
necessary, per Revision 05 of DC-9 Service Bulletin 54-031.
    We also have further clarified paragraphs (k) and (l) of this 
supplemental NPRM to specify that if any cracking is detected, 
modification of the rear spar upper strap (cap) is required per 
Revision 05. We further specify in paragraph (n) of this supplemental 
NPRM that accomplishment of that modification per Revision 05 
constitutes terminating action for the repetitive inspection 
requirements of the AD. As explained in the ``Explanation of New 
Service Information'' section of this supplemental NPRM, Boeing has 
also issued Alert Service Bulletin DC9-54A031, Revision 09, dated 
September 3, 2002, to reference accomplishment of the actions specified 
in Revision 05 of Service Bulletin DC9-54-031.

Request To Clarify the Intent of Paragraph (f) and (n) of the NPRM

    One commenter questions whether paragraph (f)(2)(ii) of the NPRM is 
acceptable as terminating action for the requirements of the AD. The 
commenter requests that, if paragraph (f)(2)(ii) of the NPRM is 
acceptable as terminating action for the requirements of the AD, that 
such provision be added to paragraph (o) of the NPRM. (Paragraph (o) of 
the NPRM states that accomplishment of the modification required by 
paragraph (l) or (n) of the NPRM constitutes compliance with AD 96-10-
11, amendment 39-9618 (61 FR 24675, May 16, 1996) and AD 72-09-01, 
amendment 39-2844 (42 FR 11235, February 28 1977).) For that same 
reason, the commenter also requests that a statement be added to 
paragraph (f)(2)(ii) of the NPRM indicating that, if the requirements 
of paragraph (f)(2)(ii) of the NPRM are accomplished, no further action 
is required by the AD. The commenter states that clarifying paragraph 
(f)(2)(ii) of the NPRM would eliminate any confusion as to whether 
further rework is required for previously modified airplanes. 
Additionally, the commenter states that paragraph (n) of the NPRM does 
not clearly specify that it does not apply to airplanes on which the 
modification specified in paragraph (f)(2)(ii) of the NPRM has been 
accomplished.
    The FAA agrees that clarification of the intent of paragraphs (f) 
and (n) of the NPRM is necessary. The modification specified in 
paragraph (f)(2)(ii) of the NPRM does not specify or include certain 
actions that are described in Revision 05 of Boeing Service Bulletin 
DC9-54-031, which was described previously in this supplemental NPRM. 
We have determined that the actions specified in Revision 05 must be 
accomplished in order to terminate the actions specified in this 
supplemental NPRM. We have revised paragraph (f)(2)(ii) of this 
supplemental NPRM to clearly specify that accomplishment of the 
modification specified in that paragraph only terminates the 
inspections specified in paragraph (f)(2)(i) of this supplemental NPRM. 
For those reasons, no change in this regard is necessary to paragraph 
(o) of the supplemental NPRM. Additionally, we have revised paragraph 
(n) of this supplemental NPRM to clarify that all airplanes must 
accomplish the modification specified in paragraph (n) of this 
supplemental NPRM, regardless of whether or not the modification 
specified in paragraph (f)(2)(ii) of this supplemental NPRM has been 
accomplished previously.

Explanation of Change to Applicability

    We have revised the applicability of the original NPRM to identify 
model designations as published in the most recent type certificate 
data sheet for the affected models. This change also is reflected in 
the Cost Impact section of this supplemental NPRM. In addition, the 
Cost Impact section has been updated to reflect the correct number of 
affected airplanes in the worldwide and U. S. fleet.

Conclusion

    Since these changes expand the scope of the original NPRM, the FAA 
has determined that it is necessary to reopen the comment period to 
provide additional opportunity for public comment.

Changes to 14 CFR Part 39/Effect on the Proposed AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. This regulation now includes material that relates 
to altered products, special flight permits, and alternative methods of 
compliance (AMOCs). Because we have now included this material in part 
39, only the office authorized to approve AMOCs is identified in each 
individual AD (i.e., paragraph (p)(1) of this supplemental NPRM). Note 
6 of the original NPRM, which discusses AMOCs approved previously, has 
been incorporated into paragraph (p)(2) of this supplemental NPRM. 
Accordingly, Note 1, Note 5, and paragraph (g) of the original NPRM 
have been removed from this supplemental NPRM.

Change in Labor Rate Estimate

    The FAA has recently reviewed the figures it has used over the past 
several years in calculating the economic impact of AD activity. In 
order to account for various inflationary costs in the airline 
industry, we find it appropriate to increase the labor rate used in 
these calculations from $60 per work hour to $65 per work hour. The 
cost impact information, below, has been revised to reflect the 
increase in the specified hourly labor rate.

Cost Impact

    There are approximately 577 Model DC-9-10, DC-9-20, DC-9-30, DC-9-
40, and DC-9-50 series airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 350 airplanes of U.S. registry 
would be affected by this proposed AD.
    The ultrasonic inspection that is currently required by AD 78-01-
16, and retained in this proposed AD, takes approximately 3 work hours 
per airplane to accomplish, at an average labor rate of $65 per work 
hour. Based on these figures, the cost impact of this currently 
required action on U.S. operators is estimated to be $195 per airplane, 
per inspection cycle.
    The new ultrasonic inspection that is proposed in this AD action 
would take approximately 4 work hours per airplane to accomplish, at an 
average labor rate of $65 per work hour. Based on these figures, the 
cost impact of the new ultrasonic inspection proposed by this AD on 
U.S. operators is estimated to be $260 per airplane, per inspection 
cycle.
    The new modification of the rear spar upper strap (cap) that is 
proposed in this AD action would take between approximately 349 and 412 
work hours to accomplish (depending on the configuration of the 
affected airplane), at an average labor rate of $65 per work hour. The 
cost of required parts would be between approximately $1,865 and $7,947 
per airplane. Based on these figures, the cost impact of the new 
modification proposed by this AD on U.S. operators is estimated to be 
between $24,550 and $34,727 per airplane.
    For certain airplanes, the repetitive visual inspections of the 
upper rear spar (cap) for bearing migration and correct pin staking 
would take approximately 20 work hours per airplane to accomplish, at 
an average labor rate of $65 per work hour. Based on these figures, the 
cost impact of that

[[Page 71043]]

inspection is estimated to be $1,300 per airplane, per inspection 
cycle.
    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. 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.
    Should an operator elect to accomplish the optional magnetic 
particle inspection that would be provided by this AD action, it would 
take approximately 7 work hours to accomplish it, at an average labor 
rate of $65 per work hour. Based on these figures, the cost impact of 
this action would be $455 per airplane, per inspection cycle.

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 removing amendment 39-3117 (43 FR 
1300, January 9, 1978), and by adding a new airworthiness directive 
(AD), to read as follows:

McDonnell Douglas: Docket 99-NM-255-AD. Supersedes AD 78-01-16, 
Amendment 39-3117.

    Applicability: Model DC-9-10, DC-9-20, DC-9-30, DC-9-40, and DC-
9-50 series airplanes, as listed in Boeing Service Bulletin DC9-54-
031, Revision 05, dated April 25, 2003; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct fatigue cracking, which could result in 
major damage to the adjacent structure of the pylon aft spar upper 
cap, and consequent reduced structural integrity of the airplane; 
accomplish the following:

Restatement of Certain Requirements of AD 78-01-16, Amendment 39-3117

Compliance Times

    (a) For airplanes that have accumulated 35,000 or more total 
landings as of February 13, 1978 (the effective date of AD 78-01-
16): Within 600 landings after February 13, 1978, unless already 
accomplished within the last 1,800 landings, and thereafter at 
intervals not to exceed 2,400 landings, accomplish the actions 
specified in paragraph (f) of this AD.
    (b) For airplanes that have accumulated between 30,000 and 
34,999 total landings inclusive, as of February 13, 1978: Within 900 
landings after February 13, 1978, unless already accomplished within 
the last 1,500 landings, and thereafter at intervals not to exceed 
2,400 landings, accomplish the actions specified in paragraph (f) of 
this AD.
    (c) For airplanes that have accumulated between 25,000 and 
29,999 total landings inclusive, as of February 13, 1978: Within 
1,200 landings after February 13, 1978, unless already accomplished 
within the last 1,200 landings, and thereafter at intervals not to 
exceed 2,400 landings, accomplish the actions specified in paragraph 
(f) of this AD.
    (d) For airplanes that have accumulated between 15,000 and 
24,999 total landings inclusive, as of February 13, 1978: Within 
2,000 landings after February 13, 1978, unless already accomplished 
within the last 400 landings, and thereafter at intervals not to 
exceed 2,400 landings, accomplish the actions specified in paragraph 
(f) of this AD.
    (e) For airplanes that have accumulated less than 15,000 total 
landings as of February 13, 1978: Within 2,000 landings after the 
accumulation of 15,000 total landings, and thereafter at intervals 
not to exceed 2,400 landings, accomplish the actions specified in 
paragraph (f) of this AD.

Repetitive Inspections and Corrective Actions

    (f) For airplanes having fuselage numbers 1 through 851 
inclusive: At the times specified in paragraphs (a) through (e) of 
this AD, except as provided by paragraph (l) of this AD, perform an 
ultrasonic inspection of the engine pylon aft upper spar straps 
(caps), part number (P/N) 9958154-5/-6 or P/N 9958154-37/-38, to 
detect cracking; in accordance with paragraph 2.B of McDonnell 
Douglas DC-9 Service Bulletin A54-31, Revision 1, dated December 22, 
1976; or in accordance with a method approved by the Manager, Los 
Angeles Aircraft Certification Office (ACO), FAA.
    (1) If there is evidence of cracking, the magnetic particle 
inspection specified in paragraph 2.C of the service bulletin may be 
used to confirm the evidence of cracking.
    (2) If any cracking is detected, prior to further flight, 
accomplish either paragraph (f)(2)(i) or (f)(2)(ii) of this AD in 
accordance with the service bulletin.
    (i) Replace the strap with a new strap, P/N 9958154-5/-6 or P/N 
9958154-37/-38, and repeat the inspection thereafter at intervals 
not to exceed 15,000 landings. Or,
    (ii) Modify the engine pylon rear spar straps (caps) in 
accordance with McDonnell Douglas DC-9 Service Bulletin 54-31, dated 
August 24, 1976. Accomplishment of the modification constitutes 
terminating action for the repetitive inspection requirements 
specified only in paragraph (f)(2)(i) of this AD.

    Note 1: Modification of the engine pylon rear spar straps (caps) 
accomplished prior to the effective date of this AD in accordance 
with McDonnell Douglas DC-9 Alert Service Bulletin A54-31, Revision 
2, dated December 22, 1977; Revision 3, dated June 20, 1986; 
Revision 4, dated March 26, 1987; Revision 5, dated March 25, 1991; 
or Revision 6, dated November 23, 1992; is considered acceptable for 
compliance with the requirements of paragraph (f)(2)(ii) of this AD.


    Note 2: Ultrasonic or magnetic particle inspection of the engine 
pylon aft upper spar straps (caps) accomplished prior to the 
effective date of this AD in accordance with McDonnell Douglas DC-9 
Alert Service Bulletin A54-31, Revision 2, dated December 22, 1977; 
Revision 3, dated June 20, 1986; Revision 4, dated March 26, 1987; 
Revision 5, dated March 25, 1991; or Revision 6, dated November 23, 
1992; is considered acceptable for compliance with the inspection 
requirements of paragraph (f) of this AD, as applicable.

New Requirements of This AD

Ultrasonic Inspections

    (g) For airplanes on which the modification/replacement 
specified in paragraph (n) of this AD has not been accomplished, and 
on which the spar strap replacement specified in paragraph (f)(2)(i) 
of this AD has not been accomplished: Except as provided by 
paragraph (m) of this AD, perform an ultrasonic inspection of the 
engine pylon aft upper spar straps (caps) to detect cracking, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin DC9-54A031, Revision 09, September 3, 2002; at the 
time specified in

[[Page 71044]]

paragraph (g)(1), (g)(2), (g)(3), or (g)(4) of this AD, as 
applicable. Accomplishment of the ultrasonic inspection constitutes 
terminating action for the repetitive inspection requirements of 
paragraphs (a) through (f), including paragraph (f)(2)(i) of this 
AD.
    (1) For airplanes that have accumulated less than 25,000 total 
landings as of the effective date of this AD: After the accumulation 
of 15,000 total landings but before the accumulation of 25,000 total 
landings, or within 2,000 landings or 6 months after the effective 
date of this AD, whichever occurs latest.
    (2) For airplanes that have accumulated 25,000 to 29,999 total 
landings as of the effective date of this AD: Within 1,200 landings 
or 6 months after the effective date of this AD, whichever occurs 
later.
    (3) For airplanes that have accumulated 30,000 to 34,999 total 
landings as of the effective date of this AD: Within 900 landings or 
6 months after the effective date of this AD, whichever occurs 
later.
    (4) For airplanes that have accumulated 35,000 or more total 
landings as of the effective date of this AD: Within 600 landings or 
6 months after the effective date of this AD, whichever occurs 
later.
    (h) For airplanes on which the modification/replacement 
specified in paragraph (n) of this AD has not been accomplished, and 
on which the spar strap replacement specified in paragraph (f)(2)(i) 
of this AD has been accomplished: Except as provided by paragraph 
(m) of this AD, perform an ultrasonic inspection of the engine pylon 
aft upper spar straps (caps) to detect cracking, in accordance with 
Boeing Alert Service Bulletin DC9-54A031, Revision 09, dated 
September 3, 2003; at the time specified in paragraph (h)(1), 
(h)(2), (h)(3), or (h)(4) of this AD, as applicable. Accomplishment 
of the ultrasonic inspection constitutes terminating action for the 
repetitive inspection requirements of paragraphs (a) through (f) of 
this AD.
    (1) For airplanes that have accumulated less than 25,000 total 
landings since installation of the new spar strap (cap): After the 
accumulation of 15,000 landings since installation of the new spar 
strap (cap) but before the accumulation of 25,000 landings since 
installation of the new spar strap (cap), or within 2,000 landings 
or 6 months after the effective date of this AD, whichever occurs 
latest.
    (2) For airplanes that have accumulated between 25,000 and 
29,999 landings since installation of the new spar strap (cap): 
Within 1,200 landings or 6 months after the effective date of this 
AD, whichever occurs later.
    (3) For airplanes that have accumulated between 30,000 and 
34,999 landings since installation of the new spar strap (cap): 
Within 900 landings or 6 months after the effective date of this AD, 
whichever occurs later.
    (4) For airplanes that have accumulated 35,000 or more landings 
since installation of the new spar strap (cap): Within 600 landings 
or 6 months after the effective date of this AD, whichever occurs 
later.

    Note 3: Ultrasonic or magnetic particle inspection of the engine 
pylon aft upper spar straps (caps) accomplished prior to the 
effective date of this AD per McDonnell Douglas DC-9 Alert Service 
Bulletin DC9-54A031, Revision 07, dated August 26, 1999; or Revision 
08, dated January 31, 2000; is considered acceptable for compliance 
with the requirements of paragraph (g) or (h) of this AD, as 
applicable.

If No Cracking Is Detected--Repetitive Inspections

    (i) If no cracking is detected during the ultrasonic inspection 
required by paragraph (g) or (h) of this AD, before further flight, 
reapply sealant that was removed to accomplish those inspections, 
per Boeing Alert Service Bulletin DC9-54A031, Revision 09, dated 
September 3, 2002. Thereafter, repeat the inspection specified in 
paragraph (g) or (h) of this AD, as applicable, at intervals not to 
exceed 2,400 landings until the modification of the rear spar upper 
strap (cap) specified in paragraph (n) of this AD has been 
accomplished.

If Cracking Is Suspected

    (j) If any evidence of cracking is suspected during any 
inspection required by paragraph (g) or (h) of this AD, before 
further flight, confirm the existence of cracking by accomplishing 
the actions specified in paragraph (m) of this AD.

If Cracking Is Detected

    (k) If any cracking is detected during any inspection required 
by paragraph (g) or (h) of this AD, before further flight, modify 
the rear spar upper strap (cap) in accordance with paragraph (n) of 
this AD. Accomplishment of the modification constitutes terminating 
action for the requirements of paragraphs (g) and (h) of this AD.

Inspection for Migration of Bearings

    (l) For airplanes identified as Group 12 airplanes in Boeing 
Service Bulletin DC9-54-031, Revision 05, April 25, 2003, on which 
the modification specified in paragraph (n) of this AD has not been 
accomplished: Perform a general visual inspection for migration of 
the bearings and the correct pin staking, per the service bulletin 
at the time specified in paragraph (g) or (h) of this AD, as 
applicable.

    Note 4: 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 from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight 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.''

    (1) If none of the bearings have migrated and the pin staking is 
correct, repeat the general visual inspection at intervals not to 
exceed 2,400 landings until the straps are modified per Boeing 
Service Bulletin DC9-54-031, Revision 05, April 25, 2003.
    (2) If any bearing has migrated or the pin staking is incorrect, 
before further flight, accomplish the modification specified in 
paragraph (n) of this AD. Accomplishment of that modification 
constitutes terminating action for the repetitive inspection 
requirements of this AD.

Acceptable Method of Compliance

    (m) At the times specified in the applicable paragraph of this 
AD, it is permissible to perform a magnetic particle inspection of 
the engine pylon aft upper spar strap (cap) for cracks in lieu of 
accomplishing the ultrasonic inspection required by paragraph (g) or 
(h) of this AD; in accordance with Boeing Alert Service Bulletin 
DC9-54A031, Revision 09, dated September 3, 2002.
    (1) If no cracking is detected, before further flight, replace 
the bearing on the spar strap (cap) with a new annular groove 
bearing, in accordance with the service bulletin. Thereafter, repeat 
the inspection specified in paragraph (g) or (h) of this AD, as 
applicable, at intervals not to exceed 2,400 landings until the 
modification of the rear spar upper strap (cap) specified in 
paragraph (n) of this AD has been accomplished.
    (2) If any cracking is detected, before further flight, 
accomplish the modification of the rear upper spar strap (cap) 
required by paragraph (n) of this AD.

Terminating Modification

    (n) For all airplanes: Prior to the accumulation of 100,000 
total landings, or within 6 months after the effective date of this 
AD, whichever occurs later, modify the rear spar upper strap (cap) 
in accordance with Boeing Service Bulletin DC9-54-031, Revision 05, 
dated April 25, 2003. Accomplishment of the modification described 
in Revision 05 of that service bulletin constitutes terminating 
action for the repetitive inspection requirements of this AD.

Compliance With Certain Other Airworthiness Directives

    (o) Accomplishment of the modification required by paragraph (n) 
of this AD constitutes compliance with the following:
    (1) The actions specified in McDonnell Douglas Service Bulletin 
54-27, Revision 4, dated April 2, 1990, that are required by AD 96-
10-11, amendment 39-9618 (which references ``DC-9/MD80 Aging 
Aircraft Service Action Requirements Document'' (SARD), McDonnell 
Douglas Report MDC K1572, Revision B, dated January 15, 1993, as the 
appropriate source of service information for accomplishment of the 
modification); and,
    (2) The requirements of AD 72-09-01, amendment 39-2844 (which 
references McDonnell Douglas Service Bulletin 54-31, dated August 
24, 1976; and McDonnell Douglas Service Bulletin 54-27, Revision 4, 
dated April 2, 1990; as appropriate sources of service information 
for accomplishment of the modification).

Alternative Methods of Compliance

    (p)(1) In accordance with 14 CFR 39.19, the Manager, Los Angeles 
(ACO), FAA, is authorized to approve alternative methods of 
compliance for this AD.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD

[[Page 71045]]

78-01-06, amendment 39-3117, are approved as alternative methods of 
compliance with the corresponding provisions of this AD.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by a 
Boeing Company Designated Engineering Representative (DER) who has 
been authorized by the Manager, Los Angeles ACO, to make such 
findings.

    Issued in Renton, Washington, on December 12, 2003.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-31440 Filed 12-19-03; 8:45 am]
BILLING CODE 4910-13-P