E6-7633. Airworthiness Directives; Boeing Model 757-200, -200CB, and -300 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

The FAA is revising an earlier proposed airworthiness directive (AD) for certain Boeing Model 757-200, -200CB, and -300 series airplanes. The original NPRM would have required repetitive detailed inspections for proper functioning of the girt bar leaf springs for the escape slides to ensure the leaf springs retain the sliders and the required 0.37-inch minimum engagement between the sliders and floor fittings is achieved at passenger doors 1, 2, and 4, and corrective actions if necessary. The original NPRM resulted from a report that the escape slides failed to deploy correctly during an operator's tests of the escape slides. This action revises the original NPRM by stating that this proposed AD would not include procedures from the airplane maintenance manuals and component maintenance manuals that allow bending the girt bar retention springs. We are proposing this supplemental NPRM to prevent escape slides from disengaging from the airplane during deployment or in use, which could result in injuries to passengers or flightcrew.

DATES:

We must receive comments on this supplemental NPRM by June 13, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this supplemental NPRM.

• 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.
• Fax: [phone].
• 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.

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

FOR FURTHER INFORMATION CONTACT:

Patrick Gillespie, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this supplemental NPRM. Send your comments to an address listed in the ADDRESSES section. Include the docket number “Docket No. FAA-2005-21968; Directorate Identifier 2005-NM-077-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this supplemental NPRM. We will consider all comments received by the closing date and may amend this supplemental NPRM in light of those comments.

We will post all comments submitted, 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 supplemental NPRM. 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 the 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 Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level in the Nassif Building at the DOT street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

We proposed to amend 14 CFR part 39 with a notice of proposed rulemaking (NPRM) for an AD (the “original NPRM”) for certain Boeing Model 757-200, -200CB, and -300 series airplanes. The original NPRM was published in the Federal Register on July 27, 2005 (70 FR 43343). The original NPRM proposed to require repetitive detailed inspections for proper functioning of the girt bar leaf springs for the escape slides at passenger doors 1, 2, and 4, and corrective actions if necessary.

Comments

We have considered the following comments on the original NPRM.

Support for the Original NPRM

The Air Transport Association (ATA), on behalf of seven of its member airlines (America West, American, Continental, Delta, Northwest, and United), and Brittania Airways agree with the intent of the original NPRM.

Request To Address Bending of Retention Spring

The Air Transport Association (ATA) on behalf of its members Continental and United, noted an inconsistency with the airplane maintenance manuals (AMMs) and component maintenance manuals (CMMs) referenced in Boeing Special Attention Service Bulletins 757-52-0085 and 757-52-0086, both dated March 24, 2005. These service bulletins were referenced as the appropriate source of service information for accomplishing the proposed actions. Continental and United state that the AMMs and CMMs allow bending of the retention spring, which is not the intent of the proposed AD, and suggest that we state the intent of the AD clearly. They also suggest that the proposed AD note this difference with the AMMs.

We agree with the requests to clarify the proposal by stating that bending of the retention spring is not allowed. Since this change expands the scope of the original NPRM, we have determined that it is necessary to reopen the comment period.

Request To Revise Summary

Boeing requests that we revise the “Summary” paragraph to clarify the inspection requirements. Boeing suggests inserting the following words: “* * * to ensure the leaf springs retain the sliders and the required 0.37-inch minimum engagement between the sliders and the floor fittings is achieved * * *.”

We agree. The words Boeing suggests add detail that clarifies the summary. We have revised the “Summary” paragraph of this supplemental NPRM to include the suggested words.

Request To Correct Errors in “Differences” Paragraph and in Paragraph (g)

Boeing also requests that we revise the “Differences Between the Proposed AD and the Service Bulletin” paragraph to correct errors in the text. Boeing specifically requests that we add “/section” to the following sentence and revise the reference to the actions in Part 1 to the actions in Part 2. Boeing suggests the following wording: “However, for actions in Part 2—‘Inspection’ of the Accomplishment Instructions of the applicable service bulletin, this proposed AD would require operators to accomplish the actions in accordance with the applicable chapter/section of the AMM or CMM specified in the applicable service bulletin.” Boeing notes that these changes revise the Part reference to agree with the reference in the special attention service bulletins; and clarify the reference to the AMM and CMM.

Boeing also states that paragraph (g) of the original NPRM incorrectly references Part 1 of the service bulletin rather than Part 2. Boeing requests that we clarify paragraph (g) by adding the words “applicable” and “/section” when referring to the 757 AMM or CMM. Boeing states that making these changes would revise the supplemental NPRM to agree with the Part number in the service bulletin, and also clarify the subject of the AMM or CMM.

We agree that the reference to Part 1 in paragraph (g) of the original NPRM is incorrect. We also agree that adding the requested words would clarify paragraph (g) of the reasons stated. We have revised paragraph (g) of the supplemental NPRM to refer to Part 2 of the service bulletin, and to add the requested words. The changes also correct and clarify the “Differences” paragraph. We have revised the subject paragraph as requested.

Request for Permanent Design Modification

Northwest Airlines notes that it has had difficulty in complying with the engagement dimension required by paragraph (f) of the original NPRM. The difficulty continued after Northwest coordinated process improvements with Boeing, and after it installed new girt bar parts and assemblies. Northwest proposes that the unsafe condition be addressed by a permanent design modification to the girt bars, or by a redesign of the retention springs. Northwest states that without a design change, operators can expect a high rate of girt bar replacements.

We partially agree. We agree that the best solution to this unsafe condition is a design change that would also serve as a terminating action for the repetitive inspections. However, in lieu of a permanent design modification proposed by either Boeing or an airplane operator, we have determined that repetitive inspections for adequate retention force of the leaf spring, and for slider engagement dimension are necessary. We will continue to work with Boeing and the airplane operators to identify a permanent solution. We have also added an “Interim Action” paragraph to this supplemental NPRM to note that we do not consider the proposed actions to be a permanent solution.

Request To Include Terminating Action for Repetitive Inspections

The ATA, on behalf of its members Delta and United, requests that we evaluate Boeing Service Bulletin 757-52-0087 as a terminating action for the proposed inspections. Delta also suggests that the service bulletin should be evaluated as an action that would extend the repetitive inspection intervals. Delta notes that this service bulletin is currently pending and has not been released. This pending service bulletin would provide procedures for replacing the current leaf spring with a stronger leaf spring.

We have evaluated the procedures in pending Boeing Service Bulletin 757-52-0087. However, both we and Boeing concluded that replacing the current leaf spring with a stronger leaf spring in accordance with the pending service bulletin does not represent a final design solution for the unsafe condition in this supplemental NPRM. The actions in this pending service bulletin, based on current data, also do not provide justification for extending the repetitive interval. As noted in “Request for Permanent Design Modification” above, we do not consider the actions proposed in this supplemental NPRM to be a permanent solution. We have not changed the supplemental NPRM in this regard. However, if a new service bulletin is issued and approved, and it addresses the unsafe condition, operators may request an alternative method of compliance (AMOC) in accordance with the procedures in paragraph (h) of this proposed AD.

Request To Revise Repetitive Inspection Interval

The ATA, on behalf of America West and Continental, and Brittania Airways request that we revise the repetitive inspection interval. America West states that it would be difficult to comply with the repetitive interval of “on or after each maintenance task.” America West notes that the required maintenance records and the inability to positively account for every maintenance task would result in the inability to demonstrate compliance with the original NPRM. Brittania believes that it is punitive to require certification of AD compliance every time “on or after each maintenance task where removal of and installation of the girt bar is necessary.” Brittania states that such matters are best addressed by the maintenance manual to which responsible operators adhere. Continental does not object to doing the initial inspection within 24 months after the effective date of the forthcoming AD. However, Continental notes that it currently removes the door slides and performs an operational check of the girt bar every 36 months. Continental states that these two maintenance planning document (MPD) driven actions are independent of one another and typically do not coincide. Consequently, the actual interval can vary from 1 month to 36 months. Continental states that introducing the third program specified in the original NPRM, at 24-month intervals, would inevitably become a stand-alone door maintenance event. Continental notes that realizing the full 24-month repetitive inspection interval is unlikely due to the two MPD programs. Further, Continental believes that these girt bar inspection requirements are ideally suited as a base maintenance activity and not as a line maintenance activity.

We disagree with the request to revise the repetitive inspection interval. We acknowledge that a repetitive inspection is not the optimum solution to the unsafe condition addressed by this supplemental NPRM. In lieu of an alternative proposal, we agree with Boeing's recommendation to rely on detailed inspections until a permanent solution is developed. In developing an appropriate repetitive interval for this supplemental NPRM, we considered safety issues as well as the recommendations of the manufacturer, and the practical aspect of accomplishing the required inspection within an interval of time that corresponds to the normal maintenance schedules of most affected operators. However, maintenance programs vary from operator to operator and may be assessed individually as an alternative method of compliance (AMOC) for the actions in this supplemental NPRM. In addition, the specific operator maintenance programs may qualify as an acceptable AMOC, but the repetitive inspection as defined in this supplemental NPRM is not required by the Boeing 757 MPD. We encourage all operators to coordinate their maintenance programs with the FAA to ensure compliance with the applicable requirements and to identify suitable AMOCs. Operators may request an AMOC in accordance with the procedures in paragraph (h) of this supplemental NPRM. We have not changed the supplemental NPRM in this regard.

Suggestions for Different Inspection Methods

The ATA on behalf of American Airlines, and Brittania suggested more effective and efficient methods for conducting the proposed inspections. American Airlines states that its inspection method produces more reliable data from which to make continued serviceability determinations. Brittania maintains that its currently scheduled maintenance tasks nullify the requirement to adopt the proposed inspections.

We welcome suggestions that improve airplane safety and that also support operational requirements. To this end, paragraph (h) of this supplemental NPRM authorizes the Manager, Seattle Aircraft Certification office, FAA to approve AMOCs. Operators may request AMOCs for inspection methods in accordance with the procedures in that paragraph. We have not changed the supplemental NPRM in this regard.

Request To Revise Paragraph (e)

Boeing requests that we revise paragraph (e) of the original NPRM to delete the phrase, “unless the actions have already been done.” Boeing states that operators still have to comply with the detailed inspection and corrective actions within 24 months after the effective date of the proposed AD and repeat the inspections at the specified interval.

We disagree. The intent of paragraph (e) is to give credit to operators who have performed compliant actions before the effective date of the AD. The paragraph does not apply to ongoing actions that are required after the AD becomes effective. We have not changed the supplemental NPRM in this regard.

Request To Clarify Paragraph (f)

The ATA, on behalf of Delta, requests that we clarify the language in paragraph (f) of the original NPRM. Delta specifically would like clarification of our intent when we say “removal and installation.” Delta believes that the intent of this statement is for the removal and installation of the girt bar assembly in the slide lanyard. Delta notes that, as written, the proposed rule would require the necessary inspections for the girt bar removal and installation in the floor fittings as well as the removal and installation in the lanyard.

We disagree. The statement as written refers to only maintenance tasks that involve installation of the girt bar on the slide assembly. The statement does not pertain to girt bar slider engagement with the floor fittings. We have not changed the supplemental NPRM in this regard.

Suggestions To Revise CMM and AMM

United recommends including in the service bulletin the instructions from CMM 25-66-14. Continental requests that the AMMs be revised to remove the procedure that allows for bending of the springs.

We agree that it is best that all documents related to the AD action be consistent. However, we cannot revise manufacturers' service information. It is our understanding that Boeing is revising the CMM. If the revised information affects the AD action, we may consider further rulemaking then.

Request To Justify AD Action

Brittania notes that the original NPRM was raised in response to a single operator's experience.

We infer that Brittania believes the proposed AD is not justified. We disagree that the action is not justified and that it results from a single operator's experience. The “Summary” paragraph states that the original NPRM resulted from a report that the escape slides failed to deploy correctly during an operator's tests of the escape slides. That report prompted an FAA evaluation of the current Boeing 757 girt bar design, and of related service difficulties reported fleet-wide. We have not changed the supplemental NPRM in this regard.

Request To Revise Cost Estimate

The ATA, on behalf of American Airlines, Delta, and Northwest; and Boeing suggest changes to the number of work-hours stated to accomplish the inspection. American notes that the current estimate is appropriate only for personnel experienced with this proposed inspection. The other operators and Boeing note that the estimated cost in the service bulletin is 6.3 work-hours per airplane.

We disagree. We recognize that the operators and Boeing have experience with the required inspection and maintenance task and agree with the overall work-hour estimate. However, the cost 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. The 2 work-hour estimate is based on the task breakdown provided in Boeing Special Attention Service Bulletins 757-52-0085 and 757-52-0086, and is consistent with the work breakdowns submitted by the commenters. We have not changed the supplemental NPRM in this regard.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

Certain changes discussed above expand the scope of the original NPRM; therefore, we have determined that it is necessary to reopen the comment period to provide additional opportunity for public comment on this supplemental NPRM.

Differences Between the Supplemental NPRM and the Service Bulletins

Although the AMMs referenced in the service bulletins allow for bending of the girt bar retention springs, this supplemental NPRM would not allow any procedure that allows bending of the girt bar retention springs.

The service bulletins specify that operators may accomplish certain actions in accordance with the Boeing 757 AMM, the Boeing 757 CMM, or an “approved equivalent procedure.” However, for actions in Part 2—“Inspection” of the Accomplishment Instructions of the applicable service bulletin, this proposed AD would require operators to accomplish the actions in accordance with the applicable chapter/section of the AMM or CMM specified in the applicable service bulletin. An “approved equivalent procedure” may be used only if it is approved as an alternative method of compliance in accordance with paragraph (h) of this supplemental NPRM.

Interim Action

We consider this proposed AD interim action. If final action is later identified, we may consider further rulemaking then.

Explanation of Change to Costs of Compliance

After the original NPRM was issued, we reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $65 per work hour to $80 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Costs of Compliance

There are about 944 airplanes of the affected design in the worldwide fleet. This supplemental NPRM would affect about 632 airplanes of U.S. registry. The proposed inspection would take about 2 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the supplemental NPRM for U.S. operators is $101,120, or $160 per airplane, per inspection cycle.

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 supplemental NPRM and placed it in the AD docket. 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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-21968; Directorate Identifier 2005-NM-077-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by June 13, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 757-200 and -200CB series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 757-52-0085, dated March 24, 2005; and Boeing Model 757-300 series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 757-52-0086, dated March 24, 2005.

Unsafe Condition

(d) This AD results from a report that the escape slides failed to deploy correctly during an operator's tests of the escape slides. We are issuing this AD to prevent escape slides from disengaging from the airplane during deployment or in use, which could result in injuries to passengers or flightcrew.

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.

Detailed Inspection and Corrective Actions

(f) Within 24 months after the effective date of this AD: Do a detailed inspection for inadequate spring retention force and inadequate girt bar slider dimensions of the girt bar leaf springs for the escape slides at passenger doors 1, 2, and 4; and do any applicable corrective actions before further flight. Do all the actions in accordance with the Accomplishment Instructions of the applicable service bulletin in paragraph (f)(1) or (f)(2) of this AD, except as provided by paragraph (g) of this AD. Where the airplane maintenance manuals (AMMs) and component maintenance manuals (CMMs) referenced by the applicable service bulletin include procedures that allow bending the girt bar retention spring, this AD does not allow that procedure. Repeat the inspection thereafter at intervals not to exceed 24 months, or after each maintenance task where removal of and installation of the girt bar is necessary, whichever occurs earlier.

(1) For Boeing Model 757-200 and -200CB series airplanes: Boeing Special Attention Service Bulletin 757-52-0085, dated March 24, 2005.

(2) For Boeing Model 757-300 series airplanes: Boeing Special Attention Service Bulletin 757-52-0086, dated March 24, 2005.

Equivalent Procedures

(g) Where Part 2—“Inspection” of the applicable service bulletin in paragraph (f)(1) or (f)(2) of this AD specifies that actions may be accomplished in accordance with an “approved equivalent procedure”: The corrective actions must be accomplished in accordance with the applicable chapter/section of the Boeing 757 AMM or Boeing 757 CMM specified in the applicable service bulletin. Where the AMMs and CMMs include procedures that allow bending the girt bar retention spring, this AD does not allow that procedure.

Alternative Methods of Compliance (AMOCs)

(h)(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) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

Issued in Renton, Washington, on May 11, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.