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Proposed Rule

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

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

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.

Start Further Info

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, marcia.walters@faa.gov.

End Further Info End Preamble Start Supplemental Information

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. Start Printed Page 59152Using 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

ActionWork hoursAverage labor rate per hourPartsCost per airplaneNumber of U.S.- registered airplanesFleet cost
Inspection, per inspection cycle6$65None$390, per inspection cycle32$12,480, per inspection cycle.

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. Start Printed 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

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

Start Authority

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

End Authority
[Amended]

2. The FAA amends § 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.

Start Signature

Issued in Renton, Washington, on September 27, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 04-22268 Filed 10-1-04; 8:45 am]

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