[Federal Register Volume 68, Number 103 (Thursday, May 29, 2003)]
[Proposed Rules]
[Pages 31994-31996]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-13388]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-27-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes 
Equipped With Pratt & Whitney JT9D-3 or JT9D-7 Series Engines (Except 
JT9D-70 Series Engines)

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to Boeing Model 747 series airplanes 
equipped with Pratt & Whitney JT9D-3 or JT9D-7 series engines (except 
JT9D-70 series engines). This proposal would require detailed 
inspections of the upper and lower surface of the forward lower spar of 
the nacelle strut for cracking or other damage, and for any loose or 
damaged fasteners. This proposal would also require replacement of 
loose or damaged fasteners and, if necessary, associated repair of the 
forward lower spar. This action is necessary to detect and correct 
cracking or other damage to the upper or lower surface of the forward 
lower spar and any loose or damaged fasteners, which could result in 
reduced structural capability of nacelle struts one through four, and 
possible separation of a strut and engine from the airplane during 
flight. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by July 14, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-27-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. 2002-NM-27-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial 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.

FOR FURTHER INFORMATION CONTACT: Tamara Anderson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6421; fax (425) 917-6590.

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 2002-NM-27-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. 2002-NM-27-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of multiple loose and damaged 
fasteners and lower spar web damage of the No. 4 strut on two Boeing 
Model 747 series airplanes equipped with Pratt & Whitney JT9D-7 
engines. This damage was observed at approximately 1,900 and 2,900 
flight cycles after incorporation of the strut modification described 
in Boeing Alert Service Bulletin 747-54A2159, dated November 3, 1994. 
That modification was made mandatory by AD 95-10-16, amendment 39-9233 
(60 FR 27008, May 22, 1995). Analysis by Boeing indicates that the 
loose fasteners were the result of incorrect installation of the 
fasteners or the collars. Multiple loose fasteners allow out-of-plane 
web deflection and damage to the lower spar web and fasteners. The 
resulting damage could cause cracking and the loss of the lower spar. 
This condition, if not corrected, could result in reduced structural 
capability of the strut, and possible separation of the strut and 
engine from the airplane during flight.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
747-54A2209, dated November 8, 2001, including Evaluation Form, which 
describes procedures for the following actions:
    Part 1: A detailed inspection of (a) the upper surface of the 
forward lower spar for cracking and fretting damage to the web, forward 
bulkhead channel, and stiffeners; and (b) the fasteners in that area 
for missing heads, damage, and evidence of looseness, such as cracked 
or broken sealant and fretting or galling around the collars, nuts, or 
fastener heads.
    Part 2: A detailed inspection of (a) the lower surface of the 
forward lower spar for cracking and fretting damage to the web, c-
channel, chords, and stiffener; and (b) the fasteners in that area for 
missing heads, damage, and evidence of

[[Page 31995]]

looseness, such as cracked or broken sealant and fretting or galling 
around the collars, nuts, or fastener heads.
    Part 3: Corrective action, which includes removing loose or damaged 
fasteners, examining the fastener holes for damage or cracks using a 
high frequency eddy current (HFEC) inspection, removing cracks or 
damage by oversizing the holes, ensuring that all cracks and damage are 
removed using a follow-up HFEC inspection, reaming the hole to a 
minimum size, and installing a new fastener.
    Boeing Alert Service Bulletin 747-54A2209, dated November 8, 2001, 
also specifies that, if damage or cracking is found which cannot be 
removed by oversizing a hole per the alert service bulletin, the Boeing 
Company should be contacted for additional instructions.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the alert service bulletin described previously, except as discussed 
below.

Differences Between Alert Service Bulletin and Proposed AD

    Boeing Alert Service Bulletin 747-54A2209, dated November 8, 2001, 
specifies that the manufacturer is to be contacted for disposition of 
damage or cracks which cannot be repaired by oversizing a fastener hole 
per the alert service bulletin. The proposed AD, however, would require 
such repair to be accomplished per a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO), FAA, or per data meeting 
the type certification basis of the airplane approved by a Boeing 
Company Designated Engineering Representative who has been authorized 
by the Manager, Seattle ACO, to make such findings.
    Another difference involves inspection of the upper surface and the 
lower surface of the forward lower spar. The alert service bulletin 
recommends inspection of the upper surface after accumulation of 300 
flight cycles since modification of the strut in accordance with AD 95-
10-16. Inspection of the lower surface is to be done after accumulation 
of 1,300 flight cycles since modification. This proposed AD, however, 
provides that, for airplanes which have accumulated 1,300 or more 
flight cycles since modification of the strut, the initial inspection 
may include both the upper surface and the lower surface of the forward 
lower spar. If no damage is detected, no further action is required by 
the AD.

Cost Impact

    There are approximately 366 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 115 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take from 20 to 64 
work hours per airplane to accomplish the proposed inspections, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the cost impact of the proposed inspections is estimated to be 
between $1,200 and $3,840 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect on the States, on the relationship between the national 
Government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

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

Boeing: Docket 2002-NM-27-AD.

    Applicability: Model 747 series airplanes, equipped with Pratt & 
Whitney JT9D-3 or JT9D-7 series engines (excluding JT9D-70 series 
engines), as listed in Boeing Alert Service Bulletin 747-54A2209, 
dated November 8, 2001; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (g) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct cracking or other damage to the structure 
of the upper or lower surface of the forward lower spar and any 
loose or damaged fasteners, which could result in reduced structural 
capability of nacelle struts one through four, and possible 
separation of the strut and engine from the airplane during flight, 
accomplish the following:

Inspection of Upper Surface of Forward Lower Spar

    (a) At the later of the times shown in paragraphs (a)(1) and 
(a)(2) of this AD: Perform a detailed inspection of the upper 
surface of the forward lower spar to detect cracks, fretting damage, 
and any loose or damaged fasteners, in accordance with Part 1 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
54A2209, dated November 8, 2001, excluding Evaluation Form.
    (1) Within 500 flight cycles, but no sooner than 300 flight 
cycles, after modification of the strut in accordance with AD 95-10-
16, amendment 39-2933.
    (2) Within 6 months after the effective date of this AD; or


[[Page 31996]]


    Note 2: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

Inspection of Lower Surface of Forward Lower Spar

    (b) If the detailed inspection required by paragraph (a) of this 
AD reveals any crack or fretting damage, or any loose or damaged 
fastener: Prior to further flight, perform a detailed inspection of 
the lower surface of the forward lower spar to detect cracks, 
fretting damage, and any loose or damaged fasteners, in accordance 
with Part 2 of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-54A2209, dated November 8, 2001, excluding 
Evaluation Form.

Follow-up Inspection

    (c) If the detailed inspection of the upper surface of the 
forward lower spar required by paragraph (a) of this AD reveals no 
crack or fretting damage and no loose or damaged fastener: At the 
later of the times specified in paragraphs (c)(1) and (c)(2) of this 
AD, repeat the detailed inspection of the upper surface of the 
forward lower spar and perform a detailed inspection of the lower 
surface of the forward lower spar, in accordance with Parts 1 and 2, 
respectively, of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-54A2209, dated November 8, 2001, excluding 
Evaluation Form.
    (1) Within 1,500 flight cycles, but no sooner than 1,300 flight 
cycles, after modification of the strut, in accordance with AD 95-
10-16; or
    (2) Within 18 months after the effective date of this AD.

Optional Follow-Up Inspection

    (d) If the detailed inspection of the upper surface of the 
forward lower spar required by paragraph (a) of this AD reveals no 
crack or fretting damage, and no loose or damaged fastener: Prior to 
further flight, the operator may elect to perform a detailed 
inspection of the lower surface of the forward lower spar to detect 
cracks, fretting damage, and any loose or damaged fasteners, in 
accordance with Part 2 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-54A2209, dated November 8, 2001, 
excluding Evaluation Form, provided that the airplane has 
accumulated at least 1,300 flight cycles since modification of the 
strut per AD 95-10-16.

Corrective Action

    (e) If any detailed inspection described in paragraph (a), (b), 
(c), or (d) of this AD reveals any crack or fretting damage to the 
upper or lower surface of the forward lower spar or any loose or 
damaged fastener: Prior to further flight, accomplish the actions 
specified in paragraph (e)(1) or (e)(2) of this AD, as applicable.
    (1) If the crack or fretting damage to the upper or lower 
surface of the forward lower spar falls within the parameters 
specified in Figure 4 or 5 (as applicable) of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-54A2209, dated 
November 8, 2001, excluding Evaluation Form, and the airplane has 
accumulated 1,300 flight cycles or more since modification of the 
strut per AD 95-10-16: Remove any loose or damaged fasteners, repair 
any cracks or fretting damage to the upper or lower surface of the 
forward lower spar, and install new fasteners, in accordance with 
the Accomplishment Instructions of the service bulletin. No further 
action is required by this AD.
    (2) If the crack or fretting damage to the upper or lower 
surface of the forward lower spar does not fall within the 
parameters specified in Figure 4 or 5 (as applicable) of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
54A2209, dated November 8, 2001, excluding Evaluation Form, or if 
the airplane has accumulated fewer than 1,300 flight cycles since 
modification of the strut per AD 95-10-16: Accomplish additional 
repair per a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA, or per data meeting the type 
certification basis of the airplane approved by a Boeing Company 
Designated Engineering Representative who has been authorized by the 
Manager, Seattle ACO, to make such findings. For a repair method to 
be approved as required by this paragraph, the approval must 
specifically reference this AD.
    (f) If the detailed inspection specified in paragraph (c) or (d) 
of this AD reveals no cracks or other damage to the upper or lower 
surface of the forward lower spar and no loose or damaged fasteners, 
no further action is required by this AD.

Alternative Methods of Compliance

    (g) 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, FAA. 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.

Special Flight Permits

    (h) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on May 22, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-13388 Filed 5-28-03; 8:45 am]
BILLING CODE 4910-13-P