[Federal Register Volume 64, Number 224 (Monday, November 22, 1999)]
[Proposed Rules]
[Pages 63762-63764]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30368]


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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).

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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 filed in 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

[[Page 63763]]

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

[[Page 63764]]

(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. 99-30368 Filed 11-19-99; 8:45 am]
BILLING CODE 4910-13-P