03-22992. Airworthiness Directives; Boeing Model 747SP, 747SR, 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 Series Airplanes

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 all Boeing Model 747SP, 747SR, 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 series airplanes. This proposal would require modification of the escape slide/raft pack assembly and cable release sliders. This action is necessary to prevent improper deployment of the escape slide/raft or blockage of the passenger/crew doors in the event of an emergency evacuation, which could result in injury to passengers or crewmembers. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by October 27, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-213-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-213-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:

Keith Ladderud, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

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:

• 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.
• For each issue, state what specific change to the proposed AD is being requested.
• 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 2001-NM-213-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. 2001-NM-213-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports of improper escape slide/raft deployment and passenger/crew door blockage during slide deployment tests on certain Boeing Model 747 series airplanes. Subsequent investigation revealed that the cause of this improper deployment or door blockage was damaged pins of the slide pack cover, which could not be extracted. If the pins are not extracted, either the door will not fully open or the slide will not deploy.

We also received one report of high-deployment and non-deployment forces of the floor mounted escape slide of the upper deck during maintenance. Investigation revealed that the cable release slider did not travel enough to allow for easy extraction of the deployment cables, which can result in high-deployment forces. Further investigation revealed that the release pins can become snagged in the access hole of the outboard cover panel cone, preventing escape slide deployment.

Improper deployment of the escape slide/raft or blockage of the passenger/crew doors in the event of an emergency evacuation could result in injury to passengers or crewmembers.

Explanation of Relevant Service Information

We have reviewed and approved Boeing Special Attention Service Bulletin 747-25-3274, Revision 1, dated January 9, 2003, which describes procedures for modification of the escape slide/raft pack assembly. For Group 1 and 2 airplanes, the modification includes removing the slide packs and replacing the cover release pin cable assemblies with new assemblies containing high-strength pins, and removing the pulley guard bracket to prevent new pins from hanging on the pulley guard during slide pack release. For Group 3 through 15 airplanes, the modification includes removing the slide packs and replacing the cover release pin cable assemblies with new assemblies containing high-strength pins. For Groups 4, 6, 8, and 10 airplanes, the modification includes removing the cable guard brackets from the door 3 ramp packs.

We also have reviewed and approved Boeing Special Attention Service Bulletin 747-25-3307, dated November 21, 2002, which describes procedures for modification of the cable release sliders of the escape slide/raft pack assembly. The modification includes overhaul or replacement of the cable release sliders with new sliders and installation of washers on the outboard pack cover. This service bulletin is to be done prior to or concurrent with Service Bulletin 747-25-3274.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition.

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 service bulletins described previously, except as discussed below.

Difference Between Service Information and This Proposed AD

Although the service bulletins recommend accomplishment of the modifications at the earliest time when manpower and parts are available, or at the next scheduled slide overhaul/maintenance, respectively, we have determined that a specific compliance time is needed to ensure that the identified unsafe condition is addressed in a timely manner. In developing an appropriate compliance time for this proposed AD, we considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, and the average utilization of the affected fleet. Considering these factors, we find that a 36-month compliance time for completing the proposed actions is warranted, in that this represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

Cost Impact

There are approximately 592 airplanes of the affected design in the worldwide fleet. We estimate that 187 airplanes of U.S. registry would be affected by this proposed AD.

It would take approximately 2 work hours per escape slide to accomplish the proposed modification of the escape slide/raft pack assembly, at an average labor rate of $65 per work hour. Required parts would cost between $13,980 and $48,940 per slide. Based on these figures, the cost impact of the modification of the escape slide/raft pack assembly proposed by this AD on U.S. operators is estimated to be between $14,110 and $49,070 per slide.

Should an operator be required to accomplish the overhaul of the cable release sliders, it would take approximately 2 work hours to accomplish the proposed overhaul, at an average labor rate of $65 per work hour. Required parts cost would be negligible. Based on these figures, the cost impact of the overhaul of the cable release sliders proposed by this AD on U.S. operators is estimated to be $130 per slider.

Should an operator be required to accomplish the replacement of the cable release sliders, it would take approximately 1 work hour to accomplish the proposed replacement, at an average labor rate of $65 per work hour. Required parts would cost approximately $2,940 per slider. Based on these figures, the cost impact of the replacement of the cable release sliders proposed by this AD on U.S. operators is estimated to be $3,005 per slider.

The cost impact figures discussed above are 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.

§ 39.13

[Amended]

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

Boeing: Docket 2001-NM-213-AD.

Applicability: All Model 747SP, 747SR, 747-100, -100B, -100BSUD, -200B, -200C, -200F, and -300 series airplanes, 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 (d) 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 prevent improper deployment of the escape slide/raft or blockage of the passenger/crew doors in the event of an emergency evacuation, which could result in injury to passengers or crewmembers, accomplish the following:

Modification

(a) Within 36 months after the effective date of this AD: Modify the escape slide/raft pack assembly (includes removing the slide packs, replacing the cover release pin cable assemblies with new assemblies, and removing the pulley guard bracket, as applicable), per Boeing Special Attention Service Bulletin 747-25-3274, Revision 1, dated January 9, 2003.

(b) Prior to or concurrent with accomplishment of paragraph (a) of this AD: Modify the cable release sliders of the escape slide/raft pack assembly (includes overhauling or replacing the cable release sliders and installing washers on the outboard pack cover, as applicable), per Boeing Special Attention Service Bulletin 747-25-3307, dated November 21, 2002.

Part Installation

(c) As of the effective date of this AD, no one may install, on any airplane, a pin cable assembly with a part number listed in the “Existing Part Number” column of the table in Appendix A of Boeing Special Attention Service Bulletin 747-25-3274, Revision 1, dated January 9, 2003.

Alternative Methods of Compliance

(d) 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 Aircraft Certification Office (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 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permit

(e) Special flight permits may be issued in accordance with §§ 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 September 4, 2003.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.