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Proposed Rule

Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR 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), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR series airplanes. For certain airplanes, this proposed AD would require a material type inspection to determine if the lower forward corner reveal of the number 3 main entry doors (MEDs) is a casting. If the reveals are castings, this proposed AD would require repetitive inspection of the reveals for cracking, and corrective action if necessary. If the reveals are not castings, this proposed AD would require a detailed inspection of the reveals for a sharp edge and repetitive inspection of the reveals for cracking, and corrective action if necessary. For certain other airplanes, this AD would require only a detailed inspection of the reveals for a sharp edge and repetitive inspection of the reveals for cracking, and corrective action if necessary. For certain other airplanes, this AD would require repetitive inspection of the reveals for cracking only, and corrective action if necessary. This proposed AD results from reports of cracking and/or a sharp edge in the lower forward corner reveal of the number 3 MEDs. We are proposing this AD to detect and correct fatigue cracking of the lower forward corner reveal of the number 3 MEDs, which could lead to the door escape slide departing from the airplane when the door is opened and the slide is deployed, and consequent injuries to passengers and crew using the door escape slide during an emergency evacuation.

DATES:

We must receive comments on this proposed AD by November 5, 2007.

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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
  • Fax: (202) 493-2251.
  • Hand Delivery: Room W12-140 on the ground floor of the West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this proposed AD.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2007-29227; Directorate Identifier 2007-NM-100-AD” at the beginning 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 received 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. 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 may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone (800) 647-5527) is located on the ground floor of the West Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

On June 30, 2004, we issued an NPRM, Docket No. FAA-2004-18583, to address the identified unsafe condition. That NPRM was prompted by reports from eight operators indicating that cracking of the lower forward corner reveal of the number 3 main entry doors (MEDs) was found on several Model 747 airplanes. Of the twelve reveals that were cracked, eleven were made of cast 356 aluminum and one was made of machined 6061 aluminum. The cause of the cracking of the reveals made of cast 356 aluminum is fatigue. The cause of the cracking of the reveal made of machined 6061 aluminum was a manufacturing defect, which led to fatigue cracking.

Subsequent to issuing the NPRM, we have been working with the manufacturer to ensure that the unsafe condition is adequately addressed and appropriate service instructions are available. We have also received new data showing other issues related to the unsafe condition. In addition to the comments received for that NPRM, the data include reports that forward corner reveals installed on certain airplanes have a “sharp edge” detail at the forward edge, which could lead to fatigue cracking, and that additional airplanes are affected by the identified unsafe condition. We have determined from these data that the corrective actions proposed by that NPRM are inadequate for addressing the identified unsafe condition; therefore, we have withdrawn that NPRM and are issuing this new proposed AD. Start Printed Page 53499

Explanation of Related AD

We have previously issued AD 2007-12-11, amendment 39-15089 (72 FR 31984, June 11, 2007), which applies to certain Boeing Model 747 series airplanes. That AD requires repetitive inspections to detect cracks and/or corrosion of the girt bar support fitting at certain main entry doors (MED), and repair or replacement of the support fitting. That AD also provides for various terminating actions for the repetitive inspections. That AD also requires an inspection, for certain airplanes, for correct installation of square and conical washers in the girt bar support fitting; an inspection, for certain other airplanes, to determine if the washers are installed; and related investigative and corrective action if necessary.

Actions required by that AD are done in accordance with Boeing Service Bulletin 747-53A2378, Revision 1, dated March 10, 1994; or Boeing Service Bulletin 747-53A2378, Revision 3, dated August 11, 2005. Accomplishment of the applicable repair in this proposed AD would constitute compliance with the requirements of paragraph (q)(2)(ii) of AD 2007-12-11 for the repair of the lower forward corner casting (reveal) of the number 3 MEDs only.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 747-53-2460, Revision 1, dated February 13, 2007. The service bulletin describes procedures for inspections of the lower forward corner reveal of the number 3 MEDs, depending on the configuration of the airplane.

For airplanes identified as Group 3 airplanes: The service bulletin describes procedures for a repetitive detailed inspection for cracking of the lower forward corner reveals for cracking, and corrective action if necessary. Corrective action includes replacing the reveal with a new or reworked two-piece reveal, which would end the repetitive inspections; or replacing the reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge, doing repetitive inspections at a new compliance time after the replacement, and doing corrective action if necessary.

For airplanes identified as Group 2 airplanes and Group 1, Configuration 2 airplanes: The service bulletin describes procedures for a repetitive detailed inspection of the lower forward corner reveals for cracking, a one-time detailed inspection of the lower forward corner reveals for a sharp edge, and corrective action if necessary. The corrective actions include the following:

  • If no cracking and no sharp edge are found: Replace the reveal with a new or reworked two-piece reveal, which would end the repetitive inspections; or do repetitive detailed inspections at a new compliance time, and corrective action if necessary (as specified above in procedures for Group 3 airplanes).
  • If no cracking is found but a sharp edge is found: Replace the reveal with a new or reworked two-piece reveal, which would end the repetitive inspections; or replace the reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge, do the repetitive detailed inspections at a new compliance time after doing the replacement, and do corrective action if necessary (as specified above in procedures for Group 3 airplanes).
  • If cracking is found: Replace the reveal with a new or reworked two-piece reveal, which would end the repetitive inspection; or replace the reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge, do the repetitive detailed inspections at a new compliance time after doing the replacement, and do corrective action if necessary (as specified above in procedures for Group 3 airplanes).

For airplanes identified as Group 1, Configuration 1 airplanes: The service bulletin describes procedures for a one-time material type inspection to determine if the lower forward corner reveals are castings. If the forward corner reveal is not a casting: Do a one-time detailed inspection of the reveal for a sharp edge, repetitive inspection of the reveal for cracking, and corrective action if necessary (as specified above in procedures for Group 2 and Group 1, Configuration 2 airplanes). If the reveal is a casting: Do repetitive detailed inspections of the reveal for cracking, and corrective action if necessary. Corrective actions include the following: Weld repair the reveal and repeat the detailed inspection; replace the reveal with a new or reworked two-piece reveal, which ends the repetitive inspections; or replace the reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge, do the repetitive inspections again at a new compliance time after the replacement, and do corrective action if necessary (as specified above in procedures for Group 2 and Group 1, Configuration 2 airplanes).

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. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Difference Between the Proposed AD and the Service Bulletin.”

Difference Between the Proposed AD and the Service Bulletin

Although Step 5 of Figure 8 of the service bulletin specifies that operators may accomplish the actions on forward corner reveals made of cast 356 aluminum in accordance with “an operator's equivalent procedure,” this proposed AD would require operators to accomplish Step 5 of Figure 8 only in accordance with the procedures specified in Boeing Standard Overhaul Practices Manual (SOPM) 20-20-02. An “operator's equivalent procedure” may be used only if approved as an alternative method of compliance in accordance with paragraph (p) of this AD.

The difference described above has been coordinated with the manufacturer.

Costs of Compliance

There are about 715 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

ActionWork hoursAverage labor rate per hourCost per airplaneNumber of U.S.-registered airplanesFleet cost
Inspections4$80$320, per inspection cycle119$38,080, per inspection cycle.
Start Printed Page 53500

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

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.

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 and placed it in the AD docket. 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-29227; Directorate Identifier 2007-NM-100-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by November 5, 2007.

Affected ADs

(b) Certain requirements of this AD terminate certain requirements of AD 96-23-05, amendment 39-9810.

Applicability

(c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 747-53-2460, Revision 1, dated February 13, 2007, except airplanes that have been converted to an all-cargo configuration. The requirements of this AD also become applicable at the time when a converted airplane operating in an all-cargo configuration is converted back to a passenger or passenger/cargo configuration.

Unsafe Condition

(d) This AD results from reports of cracking and/or a sharp edge in the lower forward corner reveal of the number 3 main entry doors (MEDs). We are issuing this AD to detect and correct fatigue cracking of the lower forward corner reveal of the number 3 MEDs, which could lead to the door escape slide departing from the airplane when the door is opened and the slide is deployed, and consequent injuries to passengers and crew using the door escape slide during an emergency evacuation.

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 Reference

(f) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-53-2460, Revision 1, dated February 13, 2007.

Actions for Group 3 Airplanes

(g) For airplanes identified as Group 3 airplanes in the service bulletin: Before the accumulation of 10,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection for cracking of the lower forward corner reveals in accordance with Part 8 of the service bulletin.

(1) If no cracking is found, repeat the inspection thereafter at intervals not to exceed 6,000 flight cycles until a new or reworked two-piece reveal is installed in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement.

Note 1:

For the purpose of this AD, a one-piece machined aluminum reveal may be reworked into a two-piece reveal in accordance with Part 7 of the service bulletin after it was verified to be crack free and without a sharp edge in accordance with Part 5 of the service bulletin, or after it was confirmed to be crack free in accordance with Part 5 of the service bulletin and reworked to remove a sharp edge in accordance with Part 6 of the service bulletin.

(2) If cracking is found, do the replacement specified in paragraph (g)(2)(i) or (g)(2)(ii) of this AD.

(i) Before further flight, replace the reveal with a new or reworked two-piece reveal in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement.

(ii) Before further flight, replace the reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge in accordance with Part 3 of the service bulletin. Within 10,000 flight cycles after doing the replacement, do the inspection specified in paragraph (g) of this AD and repeat the inspection thereafter at intervals not to exceed 6,000 flight cycles until a new or reworked two-piece reveal is installed in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement with a two-piece reveal.

Note 2:

For the purpose of this AD, a one-piece machined aluminum reveal with a sharp edge may be reworked into a one-piece machined aluminum reveal without a sharp edge in accordance with Part 6 of the service bulletin after it was confirmed to be crack free in accordance with Part 5 of the service bulletin. After the sharp edge was removed, the one-piece machined aluminum reveal without a sharp edge may be further reworked into a two-piece reveal in accordance with Part 7 of the service bulletin.

Actions for Group 2 Airplanes and Group 1, Configuration 2 Airplanes

(h) For airplanes identified as Group 2 airplanes in the service bulletin: Before the accumulation of 1,500 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, do the inspection specified in paragraph (j) of this AD.

(i) For airplanes identified as Group 1, Configuration 2 airplanes in the service bulletin: Within 1,500 flight cycles after the lower forward corner reveal was last replaced or 1,000 flight cycles after the effective date of this AD, whichever occurs later, do the inspection specified in paragraph (j) of this AD.

(j) At the applicable times specified in paragraphs (h) and (i) of this AD: Do a detailed inspection of the lower forward corner reveals for cracking and a sharp edge in accordance with Part 5 of the service bulletin.

(1) If no cracking and no sharp edge is found, before the accumulation of another Start Printed Page 5350110,000 flight cycles on the lower forward corner reveal, do the detailed inspection for cracking specified in paragraph (j) of this AD and inspect thereafter at intervals not to exceed 6,000 flight cycles, until a new or reworked two-piece reveal is installed in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement.

(2) If no cracking is found but a sharp edge is found, do the action specified in paragraph (j)(2)(i) or (j)(2)(ii) of this AD.

(i) Before further flight, replace the lower forward corner reveal with a new or reworked two-piece reveal, in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement.

(ii) Before further flight, replace the reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge, in accordance with Part 3 of the service bulletin. Within 10,000 flight cycles after doing the replacement, do the actions specified in paragraph (j) of this AD, except for the inspection for a sharp edge.

(3) If cracking is found, do the action specified in paragraph (j)(3)(i) or (j)(3)(ii) of this AD.

(i) Before further flight, replace the reveal with a new or reworked two-piece reveal, in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement.

(ii) Before further flight, replace the lower forward corner reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge, in accordance with Part 3 of the service bulletin. Within 10,000 flight cycles after doing the replacement, do the actions specified in paragraph (j) of this AD, except for the inspection for a sharp edge.

Actions for Group 1, Configuration 1 Airplanes

(k) For airplanes identified as Group 1, Configuration 1 airplanes in the service bulletin: Before the accumulation of 1,500 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later, do a material type inspection to determine if the lower forward corner reveals are castings, in accordance with the service bulletin.

(1) If the forward corner reveal is not a casting: Before further flight, do the actions specified in paragraph (j) of this AD, except for the inspection for a sharp edge.

(2) If the forward corner reveal is a casting: Before the accumulation of 7,000 total flight cycles, within 2,000 flight cycles after the effective date of this AD, or within 3,000 flight cycles since the forward corner reveal was inspected in accordance with Boeing Service Bulletin 747-53A2378, whichever is later, do a detailed inspection for cracking of the lower forward corner reveal, in accordance with Part 1 of Boeing Special Attention Service Bulletin 747-53-2460, Revision 1, dated February 13, 2007.

(i) If no cracking is found: Repeat the inspection specified in paragraph (k)(2) of this AD thereafter at intervals not to exceed 3,000 flight cycles until a new or reworked two-piece lower forward corner reveal is installed in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement.

(ii) If cracking is found: Do the actions specified in paragraph (k)(2)(ii)(A), (k)(2)(ii)(B), or (k)(2)(ii)(C) of this AD.

(A) Before further flight, weld repair the reveal in accordance with Part 4 of the service bulletin. Repeat the inspection specified in paragraph (k)(2) of this AD thereafter at intervals not to exceed 3,000 flight cycles until a new or reworked two-piece reveal is installed in accordance with Part 2 of the service bulletin.

(B) Before further flight, replace the reveal with a new or reworked two-piece reveal, in accordance with Part 2 of the service bulletin. No further action is required by this paragraph for that location only after the replacement.

(C) Before further flight, replace the reveal with a new or reworked one-piece machined aluminum reveal without a sharp edge, in accordance with Part 3 of the service bulletin. Within 10,000 flight cycles after doing the replacement, do the actions specified in paragraph (j) of this AD, except for the inspection for a sharp edge.

Operator's Equivalent Procedure

(l) Although Step 5 of Figure 8 of the service bulletin specifies that operators may accomplish the actions in accordance with “an operator's equivalent procedure,” this AD requires operators to accomplish Step 5 of Figure 8 in accordance with only the procedures specified in Boeing Standard Overhaul Practices Manual (SOPM) 20-20-02 as given in the service bulletin. An “operator's equivalent procedure” may be used only if approved as an alternative method of compliance in accordance with paragraph (p) of this AD.

Compliance With AD 2007-12-11 for MED 3 Only

(m) Accomplishment of the applicable repair required by this AD constitutes compliance with the repair of the lower forward corner casting (reveal) of the number 3 MEDs only, as required by paragraph (q)(2)(ii) of AD 2007-12-11 (which specifies the actions be done in accordance with Boeing Service Bulletin 747-53A2378, Revision 1, dated March 10, 1994; or Boeing Service Bulletin 747-53A2378, Revision 3, dated August 11, 2005). Accomplishment of the actions of this AD does not terminate the remaining requirements of AD 2007-12-11.

Parts Installation

(n) As of the effective date of this AD, no person may install a door lower forward corner reveal made of cast 356 aluminum on any airplane at a location specified by this AD.

(o) As of the effective date of this AD, no person may install a door lower forward corner reveal made of machined 6061 aluminum on any airplane at a location specified by this AD, unless it has been confirmed/reworked to be without a sharp edge in accordance with the service bulletin.

Alternative Methods of Compliance (AMOCs)

(p)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

Start Signature

Issued in Renton, Washington, on September 10, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. E7-18420 Filed 9-18-07; 8:45 am]

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