[Federal Register Volume 69, Number 191 (Monday, October 4, 2004)]
[Proposed Rules]
[Pages 59151-59153]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-22268]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19228; Directorate Identifier 2004-NM-77-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 707 Airplanes and Model 
720 and 720B Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Boeing Model 707 airplanes and Model 720 and 720B series 
airplanes. This proposed AD would require repetitive inspections of the 
left and right support ribs for the main landing gear (MLG) trunnion, 
related investigative/corrective actions if necessary, and other 
specified actions. This proposed AD is prompted by reports of in-
service cracking of the support ribs for the MLG trunnion. We are 
proposing this AD to detect and correct corrosion and cracking of the 
support ribs for the MLG trunnion, which could result in collapse of 
the MLG.

DATES: We must receive comments on this proposed AD by November 18, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to  http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street SW., Room PL-401, on 
the plaza level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT:
    Technical information: Candice Gerretsen, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6428; fax (425) 917-6590.
    Plain language information: Marcia Walters, [email protected].

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

    The FAA has implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, new AD actions are posted on DMS 
and assigned a docket number. We track each action and assign a 
corresponding directorate identifier. The DMS AD docket number is in 
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane 
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier 
(``Old Docket Number'') as a cross-reference for searching purposes.

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19228; 
Directorate Identifier 2004-NM-77-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD.

[[Page 59152]]

Using the search function of that Web site, anyone can find and read 
the comments in any of our dockets, including the name of the 
individual who sent the comment (or signed the comment on behalf of an 
association, business, labor union, etc.). You can review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the Docket

    You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received reports of in-service cracking of the support ribs 
for the main landing gear (MLG) trunnion on Boeing Model 707 airplanes 
and Model 720 and 720B series airplanes. Investigation revealed that 
the cracking was caused by stress corrosion. This condition, if not 
corrected, could result in collapse of the MLG.

Relevant Service Information

    We have reviewed Boeing 707 Alert Service Bulletin A3510, dated 
January 15, 2004. Part I of the Accomplishment Instructions of the 
alert service bulletin describes procedures for doing a repetitive 
detailed inspection of the left and right support ribs for the MLG 
trunnion and related investigative/corrective and other specified 
actions. The inspection areas include both sides of the rib flanges, 
the web, the flange radius, and the support rib. The procedures 
include:
     Removing all corrosion inhibiting compound and sealant 
from the inspection areas.
     Removing the finish and blending the area smooth if 
deterioration, discoloration, blistering, wear, scratches, or raised 
rough/cracked areas in the surface finish are found.
     Contacting Boeing if blending into the base metal is 
necessary.
     Mechanically removing any corrosion.
     Contacting Boeing for repair information if any cracking 
is found.
     Applying cadmium plating to all areas where the surface 
finish was removed.
     Applying corrosion inhibitor to all exposed surfaces of 
the support fitting for the MLG trunnion.
    Part II of the Accomplishment Instructions of the alert service 
bulletin includes procedures for doing a repetitive HFEC inspection of 
the left and right support ribs for the MLG trunnion, and corrective 
and other specified actions. The inspection areas include both sides of 
the web flange, the flange radius, the area around all bolt heads/nuts 
and fastener heads/collars for the upper and lower chords, and the rib 
around the edge of the support fitting for the MLG trunnion. The 
corrective and other specified actions include:
     Removing all corrosion inhibiting compound and sealant 
from the inspection areas.
     Contacting Boeing for repair information if any cracking 
is found.
     Applying cadmium plate to all areas where the surface 
finish was removed.
     Applying corrosion inhibitor to all exposed surfaces of 
the support fitting for the MLG trunnion, both sides of the flange 
radius of the upper and lower chords, and the rib supports.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require repetitive inspections for corrosion and cracking of the 
left and right support ribs for the main landing gear (MLG) trunnion, 
related investigative/corrective actions if necessary, and other 
specified actions. The proposed AD would require you to use the service 
information described previously to perform these actions, except as 
discussed under ``Differences Between the Proposed AD and Service 
Information.''

Differences Between the Proposed AD and Service Information

    The alert service bulletin specifies that the manufacturer may be 
contacted for disposition of certain repair conditions. This proposed 
AD would require the repair of those conditions in accordance with a 
method that we have approved or in accordance with data meeting the 
type certification basis of the airplane approved by a Boeing Company 
Designated Engineering Representative whom we have authorized to make 
such findings.

Costs of Compliance

    This proposed AD would affect about 227 airplanes worldwide. The 
following table provides the estimated costs for U.S. operators to 
comply with this proposed AD.

                                                                     Estimated Costs
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                                                                                                              Number  of
                                              Work      Average                                                  U.S.-
                  Action                     hours     labor rate    Parts         Cost per  airplane         registered             Fleet cost
                                                        per hour                                               airplanes
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Inspection, per inspection cycle.........         6          $65       None   $390, per inspection cycle..             32   $12,480, per inspection
                                                                                                                             cycle.
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Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.

[[Page 59153]]

    For the reasons discussed above, I certify that the 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) 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Boeing: Docket No. FAA-2004-19228; Directorate Identifier 2004-NM-
77-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by November 18, 2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 707-100 long body, -200, 
-100B long body, and -100B short body series airplanes; and Model 
707-300, -300B, -300C, and -400 airplanes; and Model 720 and 720B 
series airplanes; certificated in any category.

Unsafe Condition

    (d) This AD was prompted by reports of in-service cracking of 
the support ribs for the main landing gear (MLG) trunnion. We are 
proposing this AD to detect and correct corrosion and cracking of 
the support ribs for the MLG trunnion, which could result in 
collapse of the MLG.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Service Bulletin References

    (f) The term ``alert service bulletin,'' as used in this AD, 
means the Accomplishment Instructions of Boeing 707 Alert Service 
Bulletin A3510, dated January 15, 2004.

Repetitive Detailed Inspection and Corrective Action

    (g) Within 6 months after the effective date of this AD: Do a 
detailed inspection for corrosion and cracking of the left and right 
support ribs of the MLG trunnion. Do the inspection in accordance 
with all of the actions in Part I of the alert service bulletin. 
Repeat the inspection thereafter at intervals not to exceed 6 
months.
    (h) If any corrosion or cracking is found during any inspection 
required by paragraph (g) of this AD: Before further flight, do all 
applicable related investigative and corrective actions, and the 
other specified actions, in accordance with the alert service 
bulletin; except, where the alert service bulletin specifies to 
contact Boeing, before further flight, repair in accordance with a 
method approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA; or in accordance with data meeting the type 
certification basis of the airplane approved by a Boeing Designated 
Engineering Representative (DER) who has been authorized by the 
Manager, Seattle ACO, to make such findings. For a repair method to 
be approved by the Manager, Seattle ACO, as required by this 
paragraph, the approval letter must specifically reference this AD.

Repetitive High Frequency Eddy Current (HFEC) Inspection and Corrective 
Action

    (i) Within 12 months after the effective date of this AD: Do a 
HFEC inspection for cracking of the left and right support ribs of 
the MLG trunnion. Do the inspection in accordance with all of the 
actions in Part II of the alert service bulletin. Repeat the 
inspection thereafter at intervals not to exceed 12 months.
    (j) If cracking is found during any inspection required by 
paragraph (i) of this AD: Before further flight, repair the cracked 
area in accordance with a method approved by the Manager, Seattle 
ACO; or in accordance with data meeting the type certification basis 
of the airplane approved by a Boeing DER who has been authorized by 
the Manager, Seattle ACO, to make such findings. For a repair method 
to be approved, the approval must specifically refer to this AD.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.
    (2) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by a 
Boeing Company DER who has been authorized by the Manager, Seattle 
ACO, to make those findings. For a repair method to be approved, the 
approval must specifically refer to this AD.

    Issued in Renton, Washington, on September 27, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-22268 Filed 10-1-04; 8:45 am]
BILLING CODE 4910-13-P