Airworthiness directives: Boeing,

[Federal Register: November 22, 1999 (Volume 64, Number 224)]

[Proposed Rules]

[Page 63762-63764]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr22no99-43]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-355-AD]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 737, 757, 767, and 777 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 certain Boeing Model 737, 757, 767, and 777 series airplanes. This proposal would require a one-time general visual inspection to determine the vendor and manufacturing date of all oxygen masks in the passenger cabin; and corrective action, if necessary. This proposal is prompted by a report that passengers were unable to activate supplemental oxygen generators during an in- flight decompression due to stress corrosion cracking of the crimped copper alloy ferrules used to secure loops on the lanyard ends. The actions specified by the proposed AD are intended to prevent failure of the supplemental oxygen system to deliver oxygen to the passengers and flight attendants in the event of decompression, which could result in injury to passengers and flight attendants.

DATES: Comments must be received by January 6, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-355-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.

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: Susan J. Letcher, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2670; fax (425) 227-1181.

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 notice may be changed in light of the comments received.

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 filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-NM-355-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. 98-NM-355-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received a report that passengers on a Boeing Model 767 series airplane were unable to activate supplemental oxygen generators during an in-flight decompression due to failure of the oxygen mask lanyards when the masks were pulled after deployment. Failure of the oxygen mask lanyards has been attributed to stress corrosion cracking of the crimped copper alloy ferrules used to secure loops on the lanyard ends. This condition, if not corrected, could result in failure of the supplemental oxygen system to deliver oxygen to the passengers and flight attendants in the event of decompression, which could result in injury to passengers and flight attendants.

The subject oxygen mask lanyards on Boeing 737, 757, and 777 series airplanes are similar to those on the affected Boeing 767 series airplanes. Therefore, all of these airplanes may be subject to the same unsafe condition.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Service Bulletins 737-35- 1049, dated September 17, 1998, including Appendix A (for Model 737 series airplanes); 757-35-0014, dated

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September 10, 1998, including Appendix A (for Model 757 series airplanes); 767-35-0033, dated September 10, 1998 including Appendix A (for Model 767 series airplanes); and 777-35-0005, dated September 3, 1998, including Appendix A (for Model 777 series airplanes). These service bulletins describe procedures for a one-time general visual inspection to determine the vendor and manufacturing date of all oxygen masks in the passenger cabin, and replacement of all lanyards on masks manufactured by Puritan-Bennett between May 1986 and July 1998 inclusive, with new lanyards which incorporate crimped metal ferrules that are not susceptible to stress corrosion cracking. 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.

Differences Between Proposed Rule and Service Bulletin

Operators should note that, although the referenced service bulletins recommend accomplishing the inspection at the next maintenance period (2C) when the oxygen mask drop test is scheduled, the FAA has determined that this interval would not address the identified unsafe condition in a timely manner. In developing an appropriate compliance time for this proposed AD, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the inspection. In light of all of these factors, the FAA finds a 4- year compliance time for initiating the proposed actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

Cost Impact

There are approximately 4,547 airplanes of the affected design in the worldwide fleet. The FAA estimates that 2,206 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 26 work hours (for Model 737 series airplanes), 38 work hours (for Model 757 series airplanes), 44 work hours (for Model 767 series airplanes), and 52 work hours (for Model 777 series airplanes) per airplane to accomplish the proposed inspection, at an average labor rate of $60 per work hour. Required parts would cost approximately $576 (for Model 737 series airplanes), $846 (for Model 757 series airplanes), $990 (for Model 767 series airplanes), and $1,170 (for Model 777 series airplanes). Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $2,849,424, or $2,136 per airplane (for Model 737 series airplanes); $1,744,308, or $3,126 per airplane (for Model 757 series airplanes); $1,016,400, or $3,630 per airplane (for Model 767 series airplanes); and $145,860, or $4,290 per airplane (for Model 777 series airplanes).

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 AD were not adopted.

Regulatory Impact

The regulations proposed herein would not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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 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.

   Sec. 39.13 [Amended]

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

   Boeing: Docket 98-NM-355-AD.

   Applicability: Model 737 series airplanes, line numbers 1 through 2984 inclusive; Model 757 series airplanes, line numbers 1 through 798 inclusive; Model 767 series airplanes, line numbers 1 through 682 inclusive; and Model 777 series airplanes, line numbers 1 through 083 inclusive; certificated in any category; and equipped with Puritan-Bennett passenger and flight attendant oxygen masks, as listed in Boeing Service Bulletins 737-35-1049, dated September 17, 1998; 757-35-0014, dated September 10, 1998; 767-35-0033, dated September 10, 1998; or 777-35-0005, dated September 3, 1998; as applicable.

   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 failure of the supplemental oxygen system to deliver oxygen to the passengers and flight attendants in the event of decompression, which could result in injury to passengers and flight attendants, accomplish the following:

   Inspection

   (a) Within 4 years after the effective date of this AD, perform a general visual inspection to determine the vendor and manufacturing date of all oxygen masks in the passenger cabin in accordance with Boeing Service Bulletin 737-35-1049, dated September 17, 1998, including Appendix A (for Model 737 series airplanes); Boeing Service Bulletin 757-35-0014, dated September 10, 1998, including Appendix A (for Model 757 series airplanes); Boeing Service Bulletin 767-35-0033, dated September 10, 1998, including Appendix A

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   (for Model 767 series airplanes); or Boeing Service Bulletin 777-35- 0005, dated September 3, 1998, including Appendix A (for Model 777 series airplanes); as applicable.

   Note 2: For the purposes of this AD, a general visual inspection is defined as: ``A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.''

   Corrective Action

   (b) If the oxygen mask is manufactured by Puritan-Bennett between May 1986 and July 1998 inclusive: Prior to further flight, replace the lanyards on the masks with new lanyards in accordance with Boeing Service Bulletins 737-35-1049, dated September 17, 1998, including Appendix A (for Model 737 series airplanes); 757-35-0014, dated September 10, 1998, including Appendix A (for Model 757 series airplanes); 767-35-0033, dated September 10, 1998, including Appendix A (for Model 767 series airplanes); or 777-35-0005, dated September 3, 1998, including Appendix A (for Model 777 series airplanes); as applicable.

   Spares

   (c) As of the effective date of this AD, no person shall install an oxygen mask manufactured by Puritan-Bennett between May 1986 and July 1998 inclusive, on any airplane, unless the lanyard has been replaced with a new lanyard in accordance with paragraph (b) of this AD.

   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, Transport Airplane Directorate. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

   Special Flight Permits

   (e) Special flight permits may be issued in accordance with Secs. 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 November 16, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-30368Filed11-19-99; 8:45 am]

   BILLING CODE 4910-13-P