[Federal Register Volume 62, Number 110 (Monday, June 9, 1997)]
[Rules and Regulations]
[Pages 31331-31336]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-14769]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-70-AD; Amendment 39-10045; AD 97-12-03]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes two existing airworthiness
directives (AD) that are applicable to certain Boeing Model 747 series
airplanes. One of those AD's currently requires inspections for
cracking, corrosion, and fracturing of the lower horizontal clevis of
the strut midspar fittings, and replacement of discrepant parts with
new or serviceable parts, or repair, if necessary. That AD also
requires inspection for removal of broken sealant of the clevis and the
fasteners, and various follow-on actions. It also provides for optional
terminating actions for the inspections. The other AD currently
requires inspection for cracking of certain fastener holes of the upper
and lower horizontal clevis legs. This amendment continues to require
inspections to detect cracking, corrosion, and fracturing of the lower
horizontal clevis; and adds corresponding inspections of the upper
horizontal clevis, and replacement of discrepant parts with new parts,
or rework, if necessary. This amendment also removes certain optional
terminating actions. This amendment is prompted by reports of cracking
of the lower and upper leg of the horizontal clevis of the midspar
fitting. The actions specified in this AD are intended to detect and
correct cracking and fracturing of the clevis, which could result in
drooping of the strut at the strut-to-wing interface, and consequent
separation of the engine and strut from the airplane.
DATES: Effective June 24, 1997.
The incorporation by reference of Boeing Alert Service Bulletin
747-54A2179, Revision 1, dated November 27, 1996, as listed in the
regulations, is approved by the Director of the Federal Register as of
June 24, 1997.
The incorporation by reference of the following publications listed
in the regulations was approved by the Director of the Federal Register
as of the specified dates:
------------------------------------------------------------------------
Approval date and Federal
Referenced service bulletin and date Register citation
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747-54A2157, January 12, 1995............. July 28, 1995 (60 FR 33333,
June 28, 1995).
747-54A2158, November 30, 1994............ July 28, 1995 (60 FR 33336,
July 28, 1995).
747-54A2159, November 3, 1994............. June 21, 1995 (60 FR 27008,
May 22, 1995).
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The incorporation by reference of certain other publications listed
in the regulations also was approved previously by the Director of the
Federal Register as of January 22, 1997 (60 FR 66201, December 12,
1996).
Comments for inclusion in the Rules Docket must be received on or
before August 8, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-70-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056.
The service information referenced in this AD may be obtained from
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington
98124-2207. This information may be examined at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at
the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Tamara Dow, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-2771;
fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: On January 13, 1988, the FAA issued AD 87-
04-13 R1, amendment 39-5836 (53 FR 2005, January 26, 1988), applicable
to certain Boeing Model 747 series airplanes. That AD revised an
existing AD to require inspection for cracking, and repair or
replacement, as necessary, of the horizontal clevis of the pylon
midspar attach fitting. That action was prompted by reports of cracking
and corrosion in the fastener holes of the
[[Page 31332]]
midspar attach fitting of the engine pylon. The actions required by
that AD are intended to detect and correct such cracking/corrosion of
the attach fitting, which could cause possible separation of the pylon
and engine from the wing.
In addition, on November 25, 1996, the FAA issued AD 96-25-01,
amendment 39-9842 (61 FR 66201, December 17, 1996), applicable to
certain Boeing Model 747 series airplanes, to require inspections to
detect broken sealant common to the lower horizontal clevis of the
inboard and outboard strut midspar fittings and of the fasteners, and
various follow-on actions. That action also requires inspections to
detect cracking, corrosion, and fracturing of the lower horizontal
clevis, and replacement of discrepant parts with new or serviceable
parts, or repair, if necessary. That action also provides for optional
terminating actions for the repetitive inspections. That action was
prompted by reports of fatigue cracking, stress corrosion cracking, and
fracturing of the horizontal clevis of the inboard midspar fitting of
the number three strut. The actions required by that AD are intended to
detect and correct such cracking and fracturing, which could result in
drooping of the strut at the strut-to-wing interface, and consequent
separation of the engine and strut from the airplane.
Other Relevant Rulemaking
The FAA has previously issued several other AD's that address
cracking in the midspar fitting clevis on Boeing Model 747 series
airplanes:
1. AD 90-06-06, amendment 39-6490 (55 FR 8374, March 7, 1990):
Among various other actions, this AD requires structural modification,
among various other actions, in accordance with Boeing Document No. D6-
35999, dated March 31, 1989. The FAA has approved an alternative method
of compliance that extends the compliance time threshold to a maximum
of three years after the airplane reaches 20,000 total flight cycles,
or until the mandated strut/wing modification is accomplished,
whichever occurs first. Additionally, ultrasonic inspections to detect
cracking of the fastener holes are required at intervals not to exceed
1,000 flight cycles in accordance with Boeing Service Bulletin 747-54-
2118, dated July 26, 1986. If cracking or corrosion is detected during
those inspections, rework or replacement of the midspar fitting with a
new or serviceable part is required, in accordance with that service
bulletin.
The FAA has approved Boeing Alert Service Bulletin 747-54A2179,
Revision 1, dated November 27, 1996, as an alternative method of
compliance for the requirements specified in AD 90-06-06, which
references Boeing Service Bulletin 747-54-2118 as the appropriate
source of service information.
2. AD 95-10-16, amendment 39-9233 (60 FR 27008, May 5, 1995): For
airplanes equipped with Pratt & Whitney Model JT9D engines (excluding
Model JT9D-70 engines), that AD requires modification of the nacelle
strut and wing structure, and inspections of the adjacent structure
that has not been replaced by the modification, in accordance with
Boeing Alert Service Bulletin 747-54A2159, dated November 3, 1994. As a
condition to extend the compliance time from 32 to 56 months, AD 95-10-
16 also requires repetitive ultrasonic inspections to detect cracking
of the aft-most two fastener holes in both strut midspar fittings on
the inboard and outboard nacelle struts, or modification of the aft-
most two fastener holes as described in Boeing Service Bulletin 747-54-
2118.
The FAA has approved the inspections of the upper and lower
horizontal legs of the strut midspar fittings and compliance times for
those inspections specified in Boeing Alert Service Bulletin 747-
54A2179, Revision 1, dated November 29, 1996, as an alternative to
those actions specified in paragraphs (a)(2)(ii)(a) and (a)(2)(iv)(a)
of AD 95-10-16.
Since the issuance of that AD, Boeing Alert Service Bulletin 747-
54A2159, Revision 1, dated June 1, 1995, and Revision 2, dated March
14, 1996, have been approved as alternative methods of compliance with
that AD.
3. AD 95-13-05, amendment 39-9285 (60 FR 33333, June 28, 1995): For
airplanes equipped with Rolls Royce Model RB211 series engines, that AD
requires modification of the strut/wing in accordance with Boeing Alert
Service Bulletin 747-54A2157, dated January 12, 1995.
Since the issuance of that AD, Boeing Alert Service Bulletin 747-
54A2157, Revision 1, dated August 3, 1995, and Revision 2, dated
November 14, 1996, have been approved as alternative methods of
compliance with the AD.
4. AD 95-13-07, amendment 39-9287 (60 FR 33336, July 28, 1995): For
airplanes equipped with General Electric Model CF6-45 or -50 series
engines, that AD requires modification of the strut/wing in accordance
with Boeing Alert Service Bulletin 747-54A2158, dated November 30,
1994.
Since issuance of that AD, Boeing Alert Service Bulletin 747-
54A2158, Revision 1, dated August 17, 1995, and Revision 2, dated
August 15, 1996, have been approved as alternative methods of
compliance with that AD.
Actions Since Issuance of AD 87-04-13 R1 and AD 96-25-01
Since the issuance of AD 96-25-01, the FAA has received reports
indicating that cracking was found of the lower and upper leg of the
horizontal clevis of the midspar fitting on Boeing Model 747 series
airplanes. The cracking was detected during inspections that were
conducted in accordance with AD 96-25-01.
One operator reported that a midspar fitting at the number three
pylon was cracked at the fourth row of fasteners from the aft end on
the upper leg of the horizontal clevis of the midspar fitting. This
operator also reported a crack on the lower leg of the midspar fitting
at the number two pylon at the second row from the aft end.
Metallurgical analysis accomplished on the midspar fitting at the
number three pylon indicates that the cause of the cracking was stress
corrosion.
The FAA also received another report indicating that cracking was
detected on the upper leg of the horizontal clevis of the midspar
fitting at the second row of fasteners from the aft end at the number
three pylon. In addition, this report indicated that cracking was also
detected on that same airplane at the number 3 pylon at the second row
from the aft end of the lower leg. The report also indicated that
terminating action specified Boeing Service Bulletin 747-54-2118, dated
July 25, 1986, had been accomplished on the affected airplane; this
service bulletin was referenced in AD 96-25-01 as the appropriate
source of service information.
Cracking or fracturing of the lower or upper horizontal clevis of
the inboard and outboard strut midspar fittings, if not detected and
corrected in a timely manner, could result in drooping of the strut at
the strut-to-wing interface, and consequent separation of the engine
and strut from the airplane.
Explanation of New Relevant Service Information
Since the issuance of AD 87-04-13 R1 and AD 96-25-01, the FAA has
reviewed and approved Boeing Alert Service Bulletin 747-54A2179,
Revision 1, dated November 27, 1996. This alert service bulletin
describes procedures for the following:
1. Removing sealant common to the lower and upper horizontal legs
of the clevis of the outboard (for certain airplanes) and the inboard
(for all airplanes) midspar fittings, and cleaning the midspar
fittings.
[[Page 31333]]
2. Performing detailed visual borescope inspections or alternative
ultrasonic/detailed visual inspections to detect cracking, corrosion,
and/or fracturing of the lower horizontal legs of the clevis of the
strut midspar fittings, and repair, if necessary.
3. Performing ultrasonic and detailed visual inspections to detect
cracking, corrosion, and/or fracturing of the upper horizontal leg of
the strut midspar fittings, and repair, if necessary.
4. Reworking only the discrepant areas or hole.
5. Reworking all fastener holes, or replacing the midspar fitting
with new fittings, as applicable, if any discrepancy is detected; this
eliminates the need for repetitive inspections.
Additionally, for all airplanes, the service bulletin references
replacement of the midspar fittings, which involves modification of the
strut/wing in accordance with the following Boeing service bulletins,
as applicable. Accomplishment of this modification eliminates the need
for repetitive inspections.
1. Boeing Alert Service Bulletin 747-54A2157, dated January 12,
1995; Revision 1, dated August 3, 1995; or Revision 2, dated November
14, 1996 (for airplanes equipped with Rolls Royce RB211 engines);
2. Boeing Alert Service Bulletin 747-54-A2158, dated November 30,
1994; Revision 1, dated August 17, 1995; or Revision 2, dated August
15, 1996 (for airplanes equipped with General Electric CFC-45/-50 or
Pratt & Whitney JT9D-70 engines); and
3. Boeing Service Bulletin 747-54A2159, dated November 3, 1994;
Revision 1, dated June 1, 1995; or Revision 2, dated March 14, 1996
(for airplanes equipped with Pratt & Whitney engines).
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of this same type design, this AD
supersedes AD 87-04-13 R1 and AD 96-25-01, as follows:
First, this AD requires removal of certain sealant common to the
lower and upper horizontal legs of the outboard (for certain airplanes)
and the inboard (for all airplanes) midspar fittings, and cleaning the
midspar fittings.
This AD continues to require repetitive detailed visual borescope
inspections to detect cracking, corrosion, and fracturing of the lower
horizontal clevis of the inboard and outboard strut midspar fittings.
Replacement of discrepant fittings with new fittings is also required,
or rework, as applicable. This AD adds ultrasonic/detailed visual
inspections as an alternative method of accomplishing those
inspections.
This AD adds repetitive ultrasonic/detailed visual inspections of
the upper horizontal clevis of the inboard and outboard strut midspar
fittings, and replacement of discrepant fittings with new fittings, or
rework, if necessary.
For airplanes on which any cracking, corrosion, or fracturing is
detected that is outside certain limits, this AD requires
accomplishment of the strut/wing modification, replacement of the
midspar fittings of the strut with new fittings, or repair in
accordance with a method approved by the FAA, as applicable.
Accomplishment of the strut/wing modification constitutes
terminating action for the repetitive inspection requirements of this
AD.
Certain actions are required to be accomplished in accordance with
Boeing Alert Service Bulletin 747-A2179, Revision 1, dated November 27,
1996, described previously. Certain other actions are required to be
accomplished in accordance with a method approved by the FAA.
Difference Between This AD and the Alert Service Bulletin
Operators should note that, while the alert service bulletin
advises operators to contact the manufacturer if the damaged area is
beyond the specified limits, this AD requires operators to repair any
such damage in accordance with a method approved by the FAA, Transport
Airplane Directorate.
Operators also should note that airplanes on which reworking of the
upper and lower horizontal clevis of the midspar fittings has been
accomplished in accordance with Boeing Service Bulletin 747-54-2118,
dated July 25, 1986, have not been included in the effectivity of the
alert service bulletin. However, the FAA has determined that, in light
of the recent reports of cracking, the rework is not sufficient to
provide adequate assurance of permanent correction of the unsafe
condition addressed by this action. Therefore, the FAA has removed the
provision for reworking from AD 96-25-01 as an optional terminating
action for the repetitive inspection requirements of this AD.
Additionally, Boeing Alert Service Bulletin 747-54A2179, Revision
1, dated November 27, 1996, describes the replacement of the midspar
fittings of the strut as an optional method of eliminating the
repetitive inspections. The alert service bulletin also references
replacement of the midspar fittings of the strut in accordance with
either the alert service bulletin or Boeing Service Bulletin 747-54-
2118, Revision 4, dated May 11, 1989, as an optional terminating
action, which eliminates the need for repetitive inspections.
However, the FAA has determined that, in light of the recent
reports of cracking discussed previously, neither the replacement nor
the rework is sufficient to provide adequate assurance of permanent
correction of the unsafe condition. Therefore, the FAA also has removed
those optional terminating actions from this AD.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ``ADDRESSES.''
All communications received on or before the closing date for comments
will be considered, and this rule may be amended in light of the
comments received. Factual information that supports the commenter's
ideas and suggestions is extremely helpful in evaluating the
effectiveness of the AD action and determining whether additional
rulemaking action would be needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-NM-70-AD.'' The
[[Page 31334]]
postcard will be date stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, may be obtained from the Rules Docket at the
location provided under the caption ``ADDRESSES.''
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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 39-5836 (53 FR
2005, January 26, 1988) and amendment 39-9842 (61 FR 66201, December
17, 1996), and by adding a new airworthiness directive (AD),
amendment 39-10045, to read as follows:
97-12-03 Boeing: Amendment 39-10045. Docket 97-NM-70-AD. Supersedes
AD 87-04-13 R1, amendment 39-5836; and AD 96-25-01, amendment 39-
9842.
Applicability: Model 747 series airplanes as listed in Boeing
Alert Service Bulletin 747-54A2179, Revision 1, dated November 27,
1996; certificated in any category, except for airplanes on which
the strut/wing modification has been accomplished in accordance with
the following Boeing alert service bulletins:
1. Boeing Alert Service Bulletin 747-54A2157, dated January 12,
1995; Revision 1, dated August 3, 1995; or Revision 2, dated
November 14, 1996;
2. Boeing Alert Service Bulletin 747-54A2158, dated November 30,
1994; Revision 1, dated August 17, 1995; or Revision 2, dated August
15, 1996; or
3. Boeing Alert Service Bulletin 747-54A2159, dated November 3,
1994; Revision 1, dated June 1, 1995; or Revision 2, dated March 14,
1996.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 (n) 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 drooping of the strut at the strut-to-wing interface,
and consequent separation of the engine and strut from the airplane
due to cracking or fracturing of the midspar fitting clevis,
accomplish the following:
Restatement of Requirements of AD 96-25-01
(a) For all airplanes: Except as provided by paragraph (d) of
this AD, perform a detailed visual borescope inspection to detect
cracking, corrosion, and/or fracturing of the lower horizontal
clevis of both midspar fittings of the inboard struts, in accordance
with Boeing Alert Service Bulletin 747-54A2179, dated June 27, 1996,
or Revision 1, dated November 27, 1996, at the time specified in
paragraph (a)(1), (a)(2), (a)(3), or (a)(4) of this AD, as
applicable.
(1) For airplanes identified as Group 1 or Group 6 in the alert
service bulletin: Perform the initial inspection at the time
specified in paragraph (a)(1)(i) or (a)(1)(ii), as applicable.
Thereafter, repeat this inspection at intervals not to exceed every
150 flight cycles, or every 3 months, whichever occurs first. (i)
Within 150 flight cycles or 60 days after January 2, 1997 (the
effective date of AD 96-25-01, amendment 39-9842), whichever occurs
first. Or
(ii) For airplanes on which terminating action has been
accomplished within 500 flight cycles prior to January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 500 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(2) For airplanes identified as Group 2 or Group 4 in the alert
service bulletin: Perform the initial inspection at the time
specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as
applicable. Thereafter, repeat this inspection at intervals not to
exceed every 300 flight cycles or 6 months, whichever occurs first.
(i) Within 150 flight cycles or 60 days after January 2, 1997,
whichever occurs first. Or
(ii) For airplanes on which terminating action has been
accomplished within 1,000 flight cycles prior to January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 1,000 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(3) For airplanes identified as Group 3 in the alert service
bulletin: Perform the initial inspection at the time specified in
paragraph (a)(3)(i) or (a)(3)(ii) of this AD, as applicable.
Thereafter, repeat this inspection at intervals not to exceed every
350 flight cycles or 6 months, whichever occurs first.
(i) Within 150 flight cycles or 60 days after January 2, 1997,
whichever occurs first. Or
(ii) For airplanes on which terminating action has been
accomplished within 1,000 flight cycles prior to January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 1,000 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(4) For airplanes identified as Group 5 in the alert service
bulletin: Perform the initial inspection at the time specified in
paragraph (a)(4)(i) or (a)(4)(ii) of this AD, as applicable.
Thereafter, repeat the inspection at intervals not to exceed every
300 flight cycles or 6 months, whichever occurs first.
(i) Within 150 flight cycles or 60 days after January 2, 1997,
whichever occurs first.
(ii) For airplanes on which terminating action has been
accomplished within 800 flight cycles prior to January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 800 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(b) For airplanes identified as Group 1 in Boeing Alert Service
Bulletin 747-54A2179, dated June 27, 1996, or Revision 1, dated
November 27, 1996: Except as provided by paragraph (e) of this AD,
perform a detailed visual borescope inspection to detect cracking,
corrosion, and/or fracturing of the lower horizontal clevis of both
midspar fittings of the outboard struts, in accordance with Boeing
Alert Service Bulletin 747-54A2179, dated June 27, 1996, or Revision
1, dated November 27, 1996, at the time specified in paragraph
(b)(1) or (b)(2) of this
[[Page 31335]]
AD, as applicable. Thereafter, repeat the inspection at intervals
not to exceed every 300 flight cycles or 6 months, whichever occurs
first.
(1) Within 200 flight cycles or 60 days after January 2, 1997,
whichever occurs first. Or
(2) For airplanes on which the terminating action has been
accomplished within the last 1,000 flight cycles prior to January 2,
1997, in accordance with Boeing Service Bulletin 747-54-2118,
Revision 1, dated May 21, 1987; Revision 2, dated April 21, 1988;
Revision 3, dated September 29, 1988; or Revision 4, dated May 11,
1989: Perform the inspection within 1,000 flight cycles or 12 months
after January 2, 1997, whichever occurs first.
New Requirements of this AD
(c) For all airplanes: After the effective date of this AD,
prior to the accomplishment of each inspection required by paragraph
(a), (b), (d), or (e), of this AD, remove the sealant common to the
lower leg of the horizontal clevis of the inboard (for all
airplanes) midspar fittings, and the outboard (for Groups 1 and 6
airplanes) and clean the midspar fittings, in accordance with Boeing
Alert Service Bulletin 747-54A2179, Revision 1, dated November 27,
1996. Prior to further flight following accomplishment of these
actions, apply corrosion inhibitive compound BMS 3-23 to any area
where the original sealant was removed or disturbed, in accordance
with Boeing Standard Operational Procedures (BSOP) 20-41-05 for
Model 747 series airplanes.
(d) Accomplishment of the actions specified in this paragraph is
an alternative to compliance with paragraph (a) of this AD. Perform
an ultrasonic/detailed visual inspection to detect cracking,
corrosion, and/or fracturing of the lower horizontal clevis of both
midspar fittings of the inboard struts, in accordance with Boeing
Alert Service Bulletin 747-54A2179, Revision 1, dated November 27,
1996, at the time specified in paragraph (d)(1), (d)(2), (d)(3), or
(d)(4) as applicable.
(1) For airplanes identified as Group 1 or 6 in the alert
service bulletin: Perform the inspections at the time specified in
paragraph (d)(1)(i) or (d)(1)(ii) of this AD. Thereafter, repeat the
inspections at intervals not to exceed every 1,000 flight cycles or
18 months, whichever occurs first.
(i) Within 150 flight cycles or 3 months after accomplishing the
last inspection required by paragraph (b) of AD 96-25-01 or
paragraph (a) of this AD.
(ii) For airplanes on which terminating action has been
accomplished within 500 flight cycles after January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 500 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(2) For airplanes identified as Group 2 or 4 in the alert
service bulletin: Perform the inspection at the time specified in
paragraph (d)(2)(i) or (d)(2)(ii) of this AD, as applicable.
Thereafter, repeat this inspection at intervals not to exceed every
1,500 flight cycles or 18 months, whichever occurs first.
(i) Within 300 flight cycles or 6 months after accomplishing the
last inspection required by paragraph (b) of AD 96-25-01 or
paragraph (a) of this AD. Or
(ii) For airplanes on which terminating action has been
accomplished within 1,000 flight cycles after January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 1,000 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(3) For airplanes identified as Group 3 in the alert service
bulletin: Perform the inspection at the time specified in paragraph
(d)(3)(i) or (d)(3)(ii) of this AD, as applicable. Thereafter,
repeat the inspection at intervals not to exceed every 2,500 flight
cycles or 18 months, whichever occurs first.
(i) Within 350 flight cycles or 6 months after accomplishing the
last inspection required by paragraph (b) of AD 96-25-01 or
paragraph (a) of this AD. Or
(ii) For airplanes on which terminating action has been
accomplished within 1,000 flight cycles after January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 1,000 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(4) For airplanes identified as Group 5 in the alert service
bulletin: Perform the inspection at the time specified in paragraph
(d)(4)(i) or (d)(4)(ii) of this AD, as applicable. Thereafter,
repeat the inspection at intervals not to exceed every 1,500 flight
cycles or 18 months, whichever occurs first.
(i) Within 300 flight cycles or 6 months after accomplishing the
last inspection required by paragraph (b) of AD 96-25-01 or
paragraph (a) of this AD. Or
(ii) For airplanes on which terminating action has been
accomplished within 800 flight cycles after January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; Revision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the initial inspection within 800 flight cycles or 12 months after
January 2, 1997, whichever occurs first.
(e) For airplanes identified as Group 1 in Boeing Alert Service
Bulletin 747-54A2179, Revision 1, dated November 27, 1996:
Accomplishment of the actions specified in this paragraph is an
alternative to compliance with paragraph (b) of this AD. Perform an
ultrasonic/detailed visual inspection to detect cracking, corrosion,
and/or fracturing of the lower horizontal clevis of both midspar
fittings of the outboard struts, in accordance with Boeing Alert
Service Bulletin 747-54A2179, Revision 1, dated November 27, 1996,
at the time specified in paragraph (e)(1) or (e)(2) of this AD, as
applicable. Thereafter, repeat the inspection at intervals not to
exceed every 2,000 flight cycles or 18 months, whichever occurs
first.
(1) Within 300 flight cycles or 6 months after accomplishing the
last inspection required by paragraph (c) of AD 96-25-01 or
paragraph (b) of this AD. Or
(2) For airplanes on which terminating action has been
accomplished within 1,000 flight cycles after January 2, 1997, in
accordance with Boeing Service Bulletin 747-54-2118, Revision 1,
dated May 21, 1987; Revision 2, dated April 21, 1988; evision 3,
dated September 29, 1988; or Revision 4, dated May 11, 1989: Perform
the inspection within 1,000 flight cycles or 12 months after January
2, 1997, whichever occurs first.
(f) For all airplanes: After the effective date of this AD,
prior to the accomplishment of each inspection required by
paragraphs (g), (h), or (i), of this AD, remove the sealant of the
upper horizontal leg surface and clean the midspar fittings in
accordance with Boeing Alert Service Bulletin 747-54A2179, Revision
1, dated November 27, 1996. Prior to further flight following
accomplishment of these actions: Restore the sealant of the upper
horizontal leg surface in accordance with the alert service
bulletin.
(g) For all airplanes: Within 90 days after the effective date
of this AD, perform an ultrasonic/detailed visual inspection to
detect cracking, corrosion, and/or fracturing of the upper
horizontal clevis of both midspar fittings of the inboard struts, in
accordance with Boeing Alert Service Bulletin 747-54A2179, Revision
1, dated November 27, 1996. Repeat the ultrasonic/detailed visual
inspection thereafter at the time specified in paragraph (g)(1),
(g)(2), or (g)(3), as applicable.
(1) For airplanes identified as Group 1 or 6 in the alert
service bulletin: Repeat at intervals not to exceed every 1,000
flight cycles or 18 months, whichever occurs first.
(2) For airplanes identified as Group 2, 4, or 5 in the alert
service bulletin: Repeat at intervals not to exceed every 1,500
flight cycles or 18 months, whichever occurs first.
(3) For airplanes identified as Group 3 in the alert service
bulletin: Repeat at intervals not to exceed every 2,500 flight
cycles or 18 months, whichever occurs first.
(h) For airplanes identified as Group 1 in Boeing Alert Service
Bulletin 747-54A2179, Revision 1, dated November 27, 1996: Within 90
days after the effective date of this AD, perform an ultrasonic/
detailed visual inspection of the upper horizontal clevis of both
midspar fittings of the outboard strut to detect cracking,
corrosion, and/or fracturing, in accordance with the alert service
bulletin. Repeat the inspection thereafter at intervals not to
exceed every 2,000 flight cycles or 18 months, whichever occurs
first.
(i) For airplanes specified in paragraph (i)(1) or (i)(2) of
this AD: Perform the actions specified in paragraph (a), (b), (d),
(e), (f), (g), or (h) of this AD, as applicable, at the time
specified in paragraph (i)(1) or (i)(2) of this AD, as applicable.
Thereafter, perform the repetitive inspections at the time specified
in paragraph (a), (b), (d), (e), (f), (g), or (h) of this AD, as
applicable.
(1) For airplanes on which rework of all the fastener holes has
been accomplished in
[[Page 31336]]
accordance with Boeing Alert Service Bulletin 747-54A2179, dated
June 27, 1996, Revision 1, dated November 27, 1996, or Boeing
Service Bulletin 747-54-2118, dated July 25, 1986: Perform the
initial inspection at the later of the times specified in paragraphs
(i)(1)(i) and (i)(1)(ii) of this AD.
(i) Prior to the accumulation of 3,000 total landings, or within
3 years after accomplishment of the rework, whichever occurs first.
Or
(ii) Within 90 days after the effective date of this AD.
(2) For airplanes on which the midspar fittings have been
replaced in accordance with Boeing Alert Service Bulletin 747-
54A2179, Revision 1, dated November 27, 1996, or Boeing Service
Bulletin 747-54-2118, dated July 25, 1986; Revision 1, dated May 21,
1987; Revision 2, dated April 21, 1988; Revision 3, dated September
29, 1988; or Revision 4, dated May 11, 1989: Perform the initial
inspection at the later of the times specified in paragraphs
(i)(2)(i) and (i)(2)(ii) of this AD.
(i) Prior to the accumulation of 5,000 landings, or within 5
years after the fitting has been replaced, whichever occurs first.
Or
(ii) Within 90 days after the effective date of this AD.
(j) For all airplanes: If any cracking, corrosion, or fracturing
is detected during any inspection required by this AD that is
outside the limits specified in Boeing Alert Service Bulletin 757-
54A2179, Revision 1, dated November 27, 1996, and the damaged area
is within the area limits specified in the alert service bulletin,
prior to further flight, accomplish the requirements of paragraph
(j)(1) or (j)(2) of this AD.
(1) Accomplish the strut/wing modification specified in
paragraph (j)(1)(i), (j)(1)(ii), or (j)(1)(iii) of this AD, as
applicable. Following accomplishment of that action, no further
action is required by this AD.
(i) For airplanes equipped with Rolls Royce Model RB211 series
engines: Accomplish the strut/wing modification in accordance with
Boeing Alert Service Bulletin 747-54A2157, Revision 2, dated
November 14, 1996. Accomplishment of this paragraph terminates the
requirements of AD 95-13-05, amendment 39-9285.
(ii) For airplanes equipped with General Electric Model CF6-45
or -50 series engines, or Pratt & Whitney Model JT9D-70 series
engines: Accomplish the strut/wing modification in accordance with
Boeing Alert Service Bulletin 747-54A2158, Revision 2, dated August
15, 1996. Accomplishment of this paragraph terminates the
requirements of AD 95-13-07, amendment 39-9287.
(iii) For airplanes equipped with Pratt & Whitney Model JT9D
series engines (excluding Model JT9D-70 engines): Accomplish the
strut/wing modification in accordance with Boeing Alert Service
Bulletin 747-54A2159, Revision 2, dated March 14, 1996.
Accomplishment of this paragraph terminates the requirements of AD
95-10-16, amendment 39-9233.
(2) Replace the midspar fittings of the strut with new fittings
in accordance with Boeing Alert Service Bulletin 747-54A2179,
Revision 1, dated November 27, 1996. Repeat the inspections
thereafter at the intervals specified in paragraph (i)(2) of this
AD.
(k) If any cracking, corrosion, or fracturing is detected during
any inspection required by this AD that is outside the limits
specified in Boeing Alert Service Bulletin 747-54A2179, Revision 1,
dated November 27, 1996, and the damaged area is outside the area
limits specified in the alert service bulletin, prior to further
flight, accomplish the requirements of either paragraph (j)(1) or
(j)(2) of this AD, or repair in accordance with a method approved by
the Manager, Seattle ACO.
(l) For all airplanes: If any cracking, corrosion, or fracturing
is detected during any inspection required by this AD and it is
within the limits specified in Boeing Alert Service Bulletin 757-
54A2179, Revision 1, dated November 27, 1996: Prior to further
flight, accomplish the requirements of paragraph (l)(1), (l)(2),
(l)(3), or (l)(4) of this AD.
(1) Rework any discrepant area in accordance with the alert
service bulletin. Following the rework, repeat the actions required
by paragraph (a), (b), (d), (e), (f), (g), or (h) of this AD, as
applicable, at the intervals specified in those paragraphs.
(2) Rework all the fastener holes in accordance with the alert
service bulletin. Within 3,000 flight cycles or 3 years after
reworking all the fastener holes, whichever occurs first: Repeat the
actions required by paragraph (i)(1) of this AD, and accomplish the
repetitive inspections required by paragraph (i) of this AD.
(3) Replace the midspar fittings in accordance with the alert
service bulletin. Within 5,000 flight cycles or 5 years after
replacing the midspar fittings, whichever occurs first: Repeat the
actions required by paragraph (i)(2) of this AD, and accomplish the
repetitive inspections required by paragraph (i) of this AD.
(4) Accomplish the strut/wing modification specified in
paragraph (j)(1)(i), (j)(1)(ii), or (j)(1)(iii) of this AD, as
applicable. Following accomplishment of that action, no further
action is required by this AD.
(m) Accomplishment of the strut/wing modification specified in
paragraph (j)(1)(i), (j)(1)(ii), or (j)(1)(iii) of this AD
constitutes terminating action for the requirements of this AD.
(n) 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, Seattle ACO. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add comments and then send it to the Manager,
Seattle ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(o) 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.
(p) Certain actions shall be done in accordance with the Boeing
Alert Service Bulletins listed in the following table. The
incorporation by reference of those documents was approved
previously by the Director of the Federal Register, in accordance
with 5 U.S.C. 552(a) and 1 CFR part 51, as of the dates specified in
the table below:
------------------------------------------------------------------------
Approval Date and Federal
Referenced Service Bulletin and Date Register Citation
------------------------------------------------------------------------
747-54A2157, January 12, 1995............. July 28, 1995 (60 FR 33333,
June 28, 1995).
747-54A2158, November 30, 1994............ July 28, 1995 (60 FR 33336,
July 28, 1995).
747-54A2159, November 3, 1994............. June 21, 1995 (60 FR 27008,
May 22, 1995).
------------------------------------------------------------------------
Certain other actions shall be done in accordance with the Boeing
Alert Service Bulletins listed in the following table. The
incorporation by reference of those documents was approved previously
by the Director of the Federal Register on January 22, 1997 (61 FR
66201, December 12, 1996), in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51:
------------------------------------------------------------------------
Revision
Referenced Service Bulletin Level Date
------------------------------------------------------------------------
747-54A2179......................... Original June 27, 1996.
747-54A2157......................... 1 Aug. 3, 1995.
747-54A2157......................... 2 Nov. 14, 1996.
747-54A2158......................... 1 Aug. 17, 1995.
747-54A2158......................... 2 Aug. 15, 1996.
747-54A2159......................... 1 June 1, 1995.
747-54A2159......................... 2 Mar. 14, 1996.
------------------------------------------------------------------------
Certain other actions shall be done in accordance with Boeing Alert
Service Bulletin 747-54A2179, Revision 1, dated November 27, 1996. This
incorporation by reference was approved by the Director of the Federal
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies
may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707,
Seattle, Washington 98124-2207. Copies may be inspected at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
(q) This amendment becomes effective on June 24, 1997.
Issued in Renton, Washington, on May 30, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-14769 Filed 6-6-97; 8:45 am]
BILLING CODE 4910-13-U
