[Federal Register Volume 61, Number 243 (Tuesday, December 17, 1996)]
[Rules and Regulations]
[Pages 66201-66206]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-30685]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-249-AD; Amendment 39-9842; AD 96-25-01]
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 adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 747 series airplanes. This action 
requires 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. This 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. This action also 
provides for optional terminating action for the inspections. This 
amendment is 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 specified in 
this 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.

DATES: Effective January 22, 1997.
    The incorporation by reference of certain publications, as listed 
in the regulations, is approved by the Director of the Federal Register 
as of January 22, 1997.
    The incorporation by reference of certain other publications listed 
in the regulations was approved previously by the Director of the 
Federal Register as follows:

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     Referenced publication and date                    Approval date and Federal Register citation             
----------------------------------------------------------------------------------------------------------------
Boeing Alert Service Bulletin 747-        July 28, 1995 (60 FR 33333, June 28, 1995).                           
 54A2157, January 12, 1995.                                                                                     
Boeing Alert Service Bulletin 747-        July 28, 1995 (60 FR 33336, July 28, 1995).                           
 54A2158, November 30, 1994.                                                                                    
Boeing Alert Service Bulletin 747-        June 21, 1995 (60 FR 27008, May 22, 1995).                            
 54A2159, November 3, 1994.                                                                                     
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    Comments for inclusion in the Rules Docket must be received on or 
before February 18, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-249-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,

[[Page 66202]]

Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98056-4056; telephone (206) 
227-2771; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received a report indicating 
that a complete fracture of the lower horizontal clevis of the inboard 
midspar fitting across the second row of fasteners from the aft end of 
the fitting on the number 3 strut had occurred on a Boeing Model 747-
200 series airplane equipped with Pratt & Whitney JT9D-7 series 
engines. Metallurgical analysis revealed that the fracture consisted of 
three separate cracks that were caused by fatigue from multiple origins 
on the corroded bore surface of the fitting holes. The final fracture 
of the fitting was the result of ductile separation.
    The terminating action specified in AD 87-04-13 R1, amendment 39-
5836 (53 FR 2005, January 26, 1988) had been accomplished on this 
airplane in accordance with Boeing Service Bulletin 747-54-2118, 
Revision 4, dated May 11, 1989. That terminating action consisted of an 
eddy current inspection of all the hole locations and oversizing only 
the aft two holes of the horizontal clevis for both midspar fittings. 
When the fracture was detected, the airplane had accumulated 7,070 
flight hours and 1,966 flight cycles (77,823 total flight hours and 
18,858 total flight cycles) since the accomplishment of the terminating 
action.
    Additionally, the FAA has received a report indicating that fatigue 
and stress corrosion cracking in the lower horizontal clevis common to 
the second row of fasteners from the aft end of the inboard midspar 
fitting of the number 3 strut had occurred on a Boeing Model 747-300 
series airplane equipped with Pratt & Whitney JT9D-7R4G2 series 
engines. The length of the crack was 0.67 inch; this crack was found 
during an inspection of the aft row common to the horizontal clevis in 
accordance with Boeing Service Bulletin 747-54-2118, Revision 4, dated 
May 11, 1989. When the crack was detected, the airplane had accumulated 
46,118 total flight hours and 5,485 total flight cycles.
    Cracking and fracturing in the midspar fitting clevis, if not 
detected and corrected in a timely manner, could result in a fractured 
fitting and drooping of the strut at the strut-to-wing interface, and 
consequent separation of the engine and strut from the airplane.
    Additionally, the FAA has received a report indicating that broken 
sealant of the fasteners has been detected. The existing sealant was 
removed in order to visually inspect the fittings. Investigation 
revealed loose fasteners, corrosion of the fastener holes, and surface 
corrosion of the fitting.

Other Relevant Rulemaking

    The FAA has previously issued several other AD's that address 
cracking in the midspar fitting clevis on Boeing 747 series airplanes:
    1. AD 87-04-13 R1, amendment 39-5836: Requires an ultrasonic 
inspection to detect cracking of the aft-most two fastener holes of the 
upper and lower horizontal clevis legs in accordance with Boeing 
Service Bulletin 747-54-2118, dated July 25, 1986. In addition, that AD 
also provided for rework or replacement of the pylon midspar fitting, 
which would eliminate the need for the repetitive ultrasonic 
inspections. Since the issuance of that AD, Boeing Service Bulletin 
747-54-2118, Revision 1, dated May 21, 1987; Revision 2, dated April 
21, 1988; Revision 3, dated September 29, 1988; and Revision 4, dated 
May 11, 1989; have been approved as alternative methods of compliance 
with that AD.
    2. AD 90-06-06, amendment 39-6490 (55 FR 8374, March 7, 1990): 
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 the service bulletin. 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 
Boeing Service Bulletin 747-54-2118, dated July 26, 1986.
    3. 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 inspection 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. 
Since the issuance of that AD, Boeing Alert Service Bulletin, Revision 
1, dated June 1, 1995; and Revision 2, dated March 14, 1996; have been 
approved as an alternative method of compliance with that AD.
    4. 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.
    5. 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.

Explanation of New Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
747-54A2179, dated June 27, 1996, which describes procedures for 
repetitive ultrasonic inspections to detect cracking, corrosion, and 
fracturing of the upper horizontal clevis of both midspar fittings on 
the inboard and outboard struts, and repetitive detailed visual 
(borescope) inspections to detect cracking, corrosion, and fracturing 
of the lower horizontal clevis. The alert service bulletin also 
describes replacement of discrepant parts with new or serviceable 
parts, if necessary, or rework of parts where no discrepancies are 
detected. The alert service bulletin specifies that, for certain 
airplanes, these inspections need only be accomplished on the inboard 
strut.
    For airplanes on which any cracking, corrosion, or fracturing is 
detected, the replacement referenced in the alert service bulletin 
involves modification of the strut/wing in accordance with the 
following Boeing service bulletins, as applicable:

[[Page 66203]]

    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).
    As an alternative to accomplishing the strut/wing modification, the 
alert service bulletin references 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; as additional sources of service information for 
replacement of the midspar fittings with new parts.
    Accomplishment of either the strut/wing modification or replacement 
of the midspar fittings eliminates the need for the repetitive 
inspections.
    For airplanes on which no discrepancies are detected, Boeing Alert 
Service Bulletin 747-54A2179 describes procedures for rework of the 
upper and the lower horizontal clevis of the midspar fittings of the 
inboard and outboard struts, which, if accomplished on all the fastener 
holes, eliminates the need for the repetitive inspections. The alert 
service bulletin recommends that, for certain airplanes, only rework of 
the inboard strut need be accomplished. The rework consists of 
performing an eddy current inspection in accordance with the 747 Non-
Destructive Testing (NDT) Manual D6-7170 (Part 6, Subject 51-00-00, 
Figure 19) to detect cracking of all 10 to 14 fastener hole locations 
(depending on fitting design), and repair, if necessary; oversizing all 
fastener holes and applying one coat of BMS 10-11 Type 1 primer; 
allowing the primer to dry; applying BMS 5-95 sealant in the holes and 
on the shank of the oversized fasteners; and installing the oversized 
fasteners wet. The alert service bulletin references Boeing Service 
Bulletin 747-54-2118, Revision 4, dated May 11, 1989, as an additional 
source of service information for the accomplishment of this rework. In 
addition, 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; and Revision 4, dated May 11, 
1989; specify certain rework limitations of the midspar fittings.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Boeing Model 747 series airplanes of the same 
type design, this AD is being issued to detect and correct fatigue 
cracking, stress corrosion cracking, and fracturing of the inboard or 
outboard fittings of the midspar fitting 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.
    This AD requires visual inspections to detect broken sealant of the 
fasteners and various follow-on actions (visual inspection to detect 
corrosion and loose fasteners, and repair, if necessary); removal of 
the existing sealant; and, after the accomplishment of certain 
inspections required by this AD, application of specific sealant or 
corrosion inhibitive compound to all areas where the sealant was 
disturbed or removed.
    This AD also requires repetitive visual inspections to detect 
cracking, corrosion, and fracturing of the lower horizontal clevis of 
the inboard and outboard strut midspar fittings, and replacement of 
discrepant parts with new parts, if necessary, or rework, as 
applicable. For certain airplanes, this AD requires that these 
inspections be accomplished only on the inboard strut. This action also 
provides for optional terminating action, which, if accomplished, 
constitutes terminating action for the repetitive inspections.
    Certain repairs are required to be accomplished in accordance with 
a method approved by the FAA. Other actions are required to be 
accomplished in accordance with the alert service bulletin described 
previously.

Difference Between This AD and the Alert Service Bulletin

    Operators should note that while Boeing Alert Service Bulletin 747-
54A2179 describes rework procedures for airplanes on which no corrosion 
or cracking is detected, this AD specifies that rework may be 
accomplished on airplanes on which corrosion or cracking is within 
acceptable limits as specified by Figures 3 through 7 (inclusive) of 
Boeing Service Bulletin 747-54-2118.
    Operators should also note that, unlike the alert service bulletin, 
this AD requires visual inspections to detect broken sealant of the 
fasteners and various follow-on actions, if necessary (visual 
inspection to detect corrosion and loose fasteners, and repair, if 
necessary); removal of the existing sealant; and, after the 
accomplishment of certain inspections required by this AD, application 
of specific sealant or corrosion inhibitive compound to all areas where 
the sealant was disturbed or removed.
    Operators should note that this AD does not require initial or 
repetitive ultrasonic inspections of airplanes to detect cracking and 
fracturing of the upper horizontal clevis of both midspar fittings on 
the inboard and outboard struts, as described in the alert service 
bulletin.

Interim Action

    The FAA finds that, while repetitive ultrasonic inspections to 
detect cracking and fracturing of the upper horizontal clevis will 
positively address the unsafe condition addressed by this AD, the 
planned compliance time for the initial inspection is sufficiently long 
so that notice and public comment will be practicable. The FAA is, 
therefore, currently considering additional rulemaking to propose 
accomplishment of these ultrasonic inspections.
    Additionally, the manufacturer has advised that it is currently 
developing Revision 1 of Boeing Service Bulletin 747-54A2179, which 
will describe rework procedures if cracking or corrosion is detected, 
and an alternative ultrasonic/detailed visual inspection of the lower 
horizontal leg. Based on the results of a final review and approval of 
Revision 1 of the service bulletin, the FAA may also consider approving 
Revision 1 of the service bulletin as an alternative method of 
compliance for the requirements of 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

[[Page 66204]]

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 96-NM-249-AD.'' The 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 adding the following new 
airworthiness directive:

96-25-01  Boeing: Amendment 39-9842. Docket 96-NM-249-AD.

    Applicability: Model 747 series airplanes having line positions 
1 through 886; equipped with Pratt & Whitney JT9D-3, -7, and -70 
series engines, General Electric CF6-45/-50 series engines, or Rolls 
Royce RB211 series engines; certificated in any category.

    Note 1: Except as described in Note 2 of this AD, 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 (h) 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.
    Note 2: This AD does not apply to any airplane on which the 
strut midspar fittings have been modified in accordance with Boeing 
Service Bulletin 747-54-2118, which was originally released on July 
25, 1986. In addition, this AD does not apply to any airplane on 
which the strut/wing modification has been accomplished in 
accordance with the following Boeing 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.
    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:
    (a) For all airplanes: Prior to the accomplishment of each 
inspection required by paragraphs (b), (c), (d), and (e) of this AD, 
perform a visual inspection to detect any broken sealant common to 
the lower horizontal clevis of the inboard (for all airplanes) and 
the outboard (for Group 1 airplanes identified in Boeing Alert 
Service Bulletin 747-54A2179, dated June 27, 1996) midspar fittings, 
and of the fasteners, in accordance with normal maintenance 
practices.
    (1) If no broken sealant is detected, prior to further flight, 
remove the existing sealant in accordance with normal maintenance 
practices, and perform the inspections required by paragraph, (b), 
(c), (d), and/or (e) of this AD, as applicable, at the times 
specified in the applicable paragraph. Thereafter, prior to further 
flight following completion of each inspection required by paragraph 
(b), (c), (d), and/or (e) of this AD; reapply sealant to any area 
where the existing sealant was removed or disturbed, in accordance 
with Boeing 747 Maintenance Manual 51-31-01, or apply corrosion 
inhibitive compound BMS 3-23 in accordance with Boeing 747 BSOP 20-
41-05.
    (2) If any broken sealant is detected, prior to further flight, 
remove the existing sealant and perform a visual inspection of the 
fitting to detect corrosion of the fitting and check for loose 
fasteners by attempting to rotate them or move them upward with 
finger pressure.
    (i) If no corrosion or loose fastener is detected, perform the 
inspections required by paragraph (b), (c), (d), and/or (e) of this 
AD, as applicable, at the times specified in the applicable 
paragraph. Thereafter, prior to further flight following completion 
of each inspection required by paragraph (b), (c), (d), and/or (e) 
of this AD: Reapply sealant to any area where the existing sealant 
was removed or disturbed, in accordance with Boeing 747 Maintenance 
Manual 51-31-01, or apply corrosion inhibitive compound BMS 3-23 in 
accordance with Boeing 747 BSOP 20-41-05.
    (ii) If any corrosion or loose fastener is detected, prior to 
further flight, repair in accordance with a method approved by the 
Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport 
Airplane Directorate.
    (b) For all airplanes: Perform a detailed visual borescope 
inspection to detect cracking, corrosion, and 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, at the time specified in paragraph 
(b)(1), (b)(2), or (b)(3), as applicable.
    (1) For Groups 1 and 6 airplanes, as identified in the alert 
service bulletin: Perform the inspection at the time specified in 
paragraph (b)(1)(i) or (b)(1)(ii), as applicable.
    (i) Within 150 flight cycles or 60 days after the effective date 
of this AD, whichever occurs first. Or

[[Page 66205]]

    (ii) If terminating action has been accomplished 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; within the last 500 
flight cycles prior to the effective date of this AD: Perform the 
inspection required by this paragraph within 500 flight cycles or 12 
months after the effective date of this AD, whichever occur first.
    (2) For Group 2, 3, and 4 airplanes, as identified in the alert 
service bulletin: Perform the inspection at the time specified in 
paragraph (b)(2)(i) or (b)(2)(ii), as applicable.
    (i) Within 150 flight cycles or 60 days after the effective date 
of this AD, whichever occurs first. Or
    (ii) If terminating action has been accomplished 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; within the last 1000 
flight cycles prior to the effective date of this AD: Perform the 
inspection within 1000 flight cycles or 12 months after the 
effective date of this AD, whichever occurs first.
    (3) For Group 5 airplanes, as identified in the alert service 
bulletin: Perform the inspection at the time specified in paragraph 
(b)(3)(i) or (b)(3)(ii), as applicable.
    (i) Within 150 flight cycles or 60 days after the effective date 
of this AD, whichever occurs first. Or
    (ii) If terminating action has been accomplished 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; within the last 800 
flight cycles prior to the effective date of this AD: Perform the 
inspection within 800 flight cycles or 12 months after the effective 
date of this AD, whichever occurs first.
    (c) For Group 1 airplanes, as identified in Boeing Alert Service 
Bulletin 747-54A2179: Perform a detailed visual borescope inspection 
to detect cracking, corrosion, and 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, at the time specified in paragraph (c)(1) or (c)(2) 
of this AD, as applicable.
    (1) Within 200 flight cycles or 60 days after the effective date 
of this AD, whichever occurs first. Or
    (2) If terminating action has been accomplished 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; within the last 1,000 
flight cycles prior to the effective date of this AD: Perform the 
inspection within 1,000 flight cycles or 12 months after the 
effective date of this AD, whichever occurs first.
    (d) For all airplanes: Repeat the inspections of the inboard 
struts, as specified in paragraph (b) of this AD, at the time 
specified in paragraph (d)(1) or (d)(2), as applicable, until the 
terminating action specified in paragraph (f) or (g) of this AD, as 
applicable, has been accomplished.
    (1) For Groups 1 and 6 airplanes: Repeat the inspections at the 
time specified in either paragraph (d)(1)(i) or (d)(1)(ii) of this 
AD, as applicable.
    (i) Inspect thereafter at intervals not to exceed 150 flight 
cycles or 3 months, whichever occurs first. Or
    (ii) If the aft two fastener holes have been oversized, an eddy 
current inspection of the remaining holes has been performed, and 
fasteners have been installed wet with BMS 5-95 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: Inspect thereafter at 
intervals not to exceed 150 flight cycles.
    (2) For Groups 2, 3, 4, and 5 airplanes: Repeat the inspections 
at the time specified in either paragraph (d)(2)(i) or (d)(2)(ii) of 
this AD, as applicable.
    (i) Inspect thereafter at intervals not to exceed 300 flight 
cycles or 6 months, whichever occurs first. Or
    (ii) If the aft two fastener holes have been oversized, an eddy 
current inspection of the remaining holes has been performed, and 
fasteners have been installed wet with BMS 5-95 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: Inspect thereafter at 
intervals not to exceed 300 flight cycles.
    (e) For Group 1 airplanes: Repeat the inspection of the outboard 
struts, as required by paragraph (c) of this AD, at the times 
specified in either paragraph (e)(1) or (e)(2) of this AD, as 
applicable.
    (1) Inspect thereafter at intervals not to exceed 300 flight 
cycles or 6 months, whichever occurs first. Or
    (2) If the aft two fastener holes have been oversized, an eddy 
current inspection of the remaining holes has been performed, and 
fasteners have been installed wet with BMS 5-95 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: Inspect thereafter at 
intervals not to exceed 300 flight cycles.
    (f) For all airplanes: If any cracking, corrosion, or fracturing 
is detected during any inspection required by this AD, and it is 
outside the limits specified in Boeing Service Bulletin 747-54-2118, 
Revision 4, dated May 11, 1989: Prior to further flight, accomplish 
the requirements of either paragraph (f)(1) or (f)(2) of this AD. 
Following accomplishment of those actions, no further action is 
required by this AD.
    (1) Accomplish the strut/wing modification specified in 
paragraph (f)(1)(i), (f)(1)(ii), or (f)(1)(iii) of this AD, as 
applicable.
    (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 also 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 also 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 also terminates the requirements of 
AD 95-10-16, amendment 39-9233.
    (2) Replace the midspar fittings of the strut with new or 
serviceable fittings in accordance with Boeing Service Bulletin 747-
54-2118, Revision 4, dated May 11, 1989.
    (g) For all airplanes: If any cracking or corrosion is detected 
during any inspection required by this AD that is within the limits 
specified in Boeing Service Bulletin 747-54-2118, Revision 4, dated 
May 11, 1989: Prior to further flight, accomplish the requirements 
of either paragraph (g)(1), (g)(2), or (g)(3) of this AD.
    (1) For Group 2, 3, 4, and 5 airplanes: Rework both the upper 
and lower horizontal clevis of the midspar fittings of each inboard 
strut, and for Group 1 airplanes, rework both the upper and lower 
horizontal clevis of the midspar fittings of each inboard and 
outboard strut, 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. Accomplishment of the requirements of this paragraph 
constitute terminating action for the requirements of this AD 
provided that the actions specified in paragraphs (g)(1)(i), 
(g)(1)(ii), (g)(1)(iii), and (g)(1)(iv) are also accomplished.
    (i) The rework shall be accomplished on all holes of the 
horizontal flanges;
    (ii) The rework shall include an eddy current inspection of all 
holes at the horizontal flanges, in accordance with Boeing Non-
Destructive Testing (NDT) Manual D6-7170 Part 6, Subject 51-00-00, 
Figure 19.
    (iii) All holes of the horizontal flanges shall be oversized and 
insurance cut an additional 0.0312 inch, in accordance with Boeing 
Service Bulletin 747-54-2118, Revision 4, dated May 11, 1989. And
    (iv) One coat of BMS 10-11 Type 1 primer shall be applied to the 
fastener holes, and the oversized fasteners shall be installed wet 
with BMS 5-95 sealant, in accordance with Boeing Service Bulletin 
747-54-2118, Revision 4, dated May 11, 1989.
    (2) For Group 2, 3, 4, and 5 airplanes: Rework both the upper 
and lower horizontal clevis of the midspar fittings of each inboard 
strut, and for Group 1 airplanes, rework both the upper and lower 
horizontal clevis of the

[[Page 66206]]

midspar fittings of each inboard and outboard strut, in accordance 
with Boeing Service Bulletin 747-54-2118, dated July 25, 1986. 
Accomplishment of the requirements of this paragraph constitute 
terminating action for the requirements of this AD.
    (3) Accomplish the rework (removal of cracking and corrosion) 
specified in Boeing Service Bulletin 747-54-2118, Revision 4, dated 
May 11, 1989, with the exception that eddy current inspections 
specified in that service bulletin must be accomplished in 
accordance with Boeing Non-Destructive Testing (NDT) Manual D6-7170 
Part 6, Subject 51-00-00, Figure 19. Thereafter, repeat the 
inspections specified in paragraph (d) or (e) of this AD, as 
applicable, at the time required by the applicable paragraph.
    (h) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (i) 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.
    (j) 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:

----------------------------------------------------------------------------------------------------------------
  Referenced service bulletin and date                  Approval date and Federal 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 
following Boeing service bulletins, which contain the specified 
effective pages:

----------------------------------------------------------------------------------------------------------------
                                                                   Revision                                     
 Service bulletin referenced and date           Page No.         level shown          Date shown on page        
                                                                   on page                                      
----------------------------------------------------------------------------------------------------------------
Alert 747-54A2179, June 27, 1996......  1-34...................        (\1\)  June 27, 1996.                    
747-54A2157, Revision 1, August 3,      1-901..................            1  August 3, 1995.                   
 1995.                                                                                                          
747-54A2157, Revision 2, November 14,   1-961..................            2  November 14, 1996.                
 1996.                                                                                                          
747-54A2158, Revision 1, August 17,     1-1,052................            1  August 17, 1995.                  
 1995.                                                                                                          
747-54A2158, Revision 2, August 15,     1-1,080D2..............   August 15,                                    
 1996.                                                                 1996.                                    
747-54A2159, Revision 1, June 1, 1995.  1-1,240................            1  June 1, 1995.                     
747-54A2159, Revision 2, March 14,      1-1,298................            2  March 14, 1996.                   
 1996.                                                                                                          
747-54-2118, July 25, 1986............  1-172..................        (\1\)  July 25, 1986.                    
Notice of Status Change, 747-54-2118    1......................        (\1\)  October 5, 1986.                  
 NSC 1, October 5, 1986.                                                                                        
747-54-2118, Revision 1, May 21, 1987.  1-175..................            1  May 21, 1987.                     
747-54-2118, Revision 2, April 21,      1-5, 7-13, 17-21, 24,              2  April 21, 1988.                   
 1988.                                   30, 31, 38, 39, 48-51,                                                 
                                         58, 59, 61, 69-72, 84,                                                 
                                         101, 117, 134, 151,                                                    
                                         170.                                                                   
                                        6, 14-16, 22, 23, 26-              1  May 21, 1987.                     
                                         29, 32-37, 40-47, 52-                                                  
                                         57, 60, 62-68, 73-83,                                                  
                                         85-100, 102-116, 118-                                                  
                                         133, 135-150, 152-169,                                                 
                                         171-175.                                                               
                                        25.....................        (\1\)  July 25, 1986.                    
747-54-2118, Revision 3, September 29,  1-6, 9, 10, 12, 21, 22.            3  September 29, 1988.               
 1988.                                                                                                          
                                        7, 8, 13-20, 23, 24, 26-           1  May 21, 1987.                     
                                         175.                                                                   
                                        11.....................            2  April 21, 1988.                   
                                        25.....................        (\1\)  July 25, 1986.                    
747-54-2118, Revision 4, May 11, 1989.  1-12, 16, 17, 21-170,              4  May 11, 1989.                     
                                         173, 174.                                                              
                                        13, 18-20..............            2  April 21, 1988.                   
                                        14, 15.................            1  May 21, 1987.                     
                                        171, 172, 175, 176.....          \1\  July 25, 1986.                    
----------------------------------------------------------------------------------------------------------------
\1\ Original.                                                                                                   

    The incorporation by reference of those documents 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.
    (k) This amendment becomes effective on January 2, 1997.

    Issued in Renton, Washington, on November 25, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-30685 Filed 12-16-96; 8:45 am]
BILLING CODE 4910-13-U