AD 2000-15-16

[Federal Register Volume 65, Number 153 (Tuesday, August 8, 2000)]
[Rules and Regulations]
[Pages 48364-48368]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-19815]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-355-AD; Amendment 39-11848; AD 2000-15-16]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737, 757, 767, and 777 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD); 
applicable to certain Boeing Model 737, 757, 767, and 777 series 
airplanes; that requires 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 amendment 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

[[Page 48365]]

ferrules used to secure loops on the lanyard ends. The actions 
specified by this 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: Effective September 12, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 12, 2000.

ADDRESSES: The service information referenced in this AD 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. This information may be examined at the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, Rules Docket, 
1601 Lind Avenue, SW., Renton, Washington; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Boeing Model 737, 757, 
767, and 777 series airplanes was published in the Federal Register on 
November 22, 1999 (64 FR 63762). That action proposed to 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.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposed AD

    Two commenters support the proposed AD.

Request To Extend Compliance Time

    Two commenters request that the FAA extend the compliance time for 
the actions proposed in paragraph (a) from four years to five years. 
One commenter states that, to comply with the proposed AD, the oxygen 
masks would have to be accessed twice: once to determine which masks 
are affected, so that an adequate number of replacement lanyards can be 
ordered, and a second time, to install the replacement lanyards. The 
other commenter states that, due to the amount of time needed to access 
and repack the oxygen marks, the inspection should be accomplished 
during a major maintenance visit. Thus, the commenters are requesting 
that the compliance time be extended to ensure that the inspection can 
be accomplished on all airplanes during a major maintenance visit.
    The FAA concurs with the commenters' request to extend the 
compliance time for the actions required by paragraph (a) from four 
years to five years. The FAA concurs that additional maintenance 
planning and work hours may be necessary to accomplish the inspection. 
The FAA finds that such an extension of the compliance time will not 
have an adverse impact on safety. Paragraph (a) has been revised 
accordingly.

Request To Increase Estimate of Cost Impact

    The commenters that request an extension of the compliance time 
also request that the FAA revise the cost impact information in the 
proposal to reflect higher work hour estimates. One commenter requests 
that the work hour estimate be doubled because operators may need to 
access the oxygen masks twice (as described above). The other commenter 
states that the estimates in the service bulletin and the proposed rule 
do not account for the time needed to repack the oxygen masks. The 
commenter asserts that the masks are generally packed such that the 
tubing obscures the manufacturer's identification. Thus, it may be 
necessary to unwrap the tubing to accomplish the inspection, and, 
following the inspection, the masks would have to be carefully 
repacked. The commenter estimates that the inspection may actually take 
1 to 2 work hours per oxygen mask.
    The FAA partially concurs with the commenters' request to increase 
the cost impact estimate. The FAA does not concur with the commenters' 
estimates of the number of necessary work hours. The commenter's 
estimates may include extra time for ``incidental'' costs. The cost 
analysis in AD rulemaking actions, however, typically does 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 FAA recognizes that, in accomplishing the requirements of 
any AD, operators may incur incidental costs in addition to the 
``direct'' costs. Because incidental costs may vary significantly from 
operator to operator, they are almost impossible to calculate.
    However, as stated previously, the FAA acknowledges that the 
actions required by this AD may take longer than estimated in the 
proposed rule. The estimated number of work hours stated in the 
proposed rule was based on a figure of 0.16 work hour per mask. That 
figure included the 0.15 work hour needed to accomplish the applicable 
Boeing service bulletin, plus 0.01 work hour to accomplish the Puritan-
Bennett service bulletin referenced in the Boeing service bulletins. In 
consideration of the fact that additional work hours may be necessary 
to accomplish certain actions required by this AD (e.g., to identify 
the manufacturer of the masks), the FAA has revised the cost impact 
information in this final rule to reflect an estimate of 0.25 work hour 
per mask, rather than the 0.16 work hour per mask estimated in the 
proposal.

Request To Remove Requirement for Certain Oxygen Masks

    One commenter requests that the FAA revise paragraph (a) of the 
proposed rule to eliminate the requirement to determine the 
manufacturing date for oxygen masks not manufactured by Puritan-
Bennett. The proposed paragraph (a) specifies a general visual 
inspection to determine both the manufacturer and the manufacturing 
date of each oxygen mask. The commenter points out that it is only 
relevant to determine the manufacturing date for masks manufactured by 
Puritan-Bennett. The commenter states that if the visual inspection 
establishes that the mask was not manufactured by Puritan-Bennett, no 
further inspection should be required. The FAA concurs with the 
commenter's request, and paragraph (a) has been revised accordingly, 
and new paragraphs (a)(1) and (a)(2) have been added to this AD. 
However, the FAA notes that, if the manufacturing date of the mask 
cannot be determined, or if the manufacturing date is between May 1986 
and July 1998 inclusive but the manufacturer of the mask cannot be 
determined, the lanyard must be replaced. Thus, paragraph (b) of this 
AD has been revised to provide for such instances.

[[Page 48366]]

Request To Allow Replacement of Mask in Lieu of Replacement of 
Lanyard

    One commenter requests that the FAA revise paragraph (b) of the 
proposed rule to allow replacement of the entire mask with a new mask 
manufactured by another vendor or manufactured outside the subject 
timeframe, in lieu of replacement of the lanyard only, if a mask is 
determined to be manufactured by Puritan-Bennett between May 1986 and 
July 1998.
    The FAA partially concurs with the commenter's request. Replacement 
of an existing oxygen mask with a new mask manufactured by Puritan-
Bennett before May 1986 or after July 1998, or manufactured by another 
vendor, would be acceptable alternatives to replacement of the lanyard, 
provided that the replacement mask has the same Boeing part number, or 
provided that the FAA has approved the replacement mask for 
installation as a replacement. Paragraph (b) of this AD has been 
revised to provide such replacement as another option for compliance.

Request To Clarify Justification of Proposed Compliance Time

    One commenter, the airplane manufacturer, requests that the FAA 
revise the proposed rule to clarify that the compliance time 
recommended by the manufacturer is shorter than the compliance time the 
FAA proposed. The commenter notes that the section, ``Differences 
Between Proposed Rule and Service Bulletin'' in the preamble of the 
proposed rule implies that the FAA proposed a compliance time of four 
years because the manufacturer's recommendation would not ensure that 
operators would comply in a timely manner. The commenter points out 
that the manufacturer's recommendation that the service bulletin be 
incorporated at the next ``2C'' check would, for most operators, result 
in accomplishment of the service bulletin earlier than the proposed 
four-year compliance time.
    The FAA acknowledges that the language in the ``Differences Between 
Proposed Rule and Service Bulletin'' section of the preamble of the 
proposed rule may have been misleading. However, this section is not 
restated in this final rule, so no change to this AD is necessary in 
this regard. The compliance time recommended by the manufacturer in its 
service bulletin is indeed more conservative than the compliance time 
specified in this AD. The FAA finds a five-year compliance time for 
completing the required actions is warranted, in that it represents an 
appropriate interval of time allowable for affected airplanes to 
continue to operate without compromising safety. As stated previously, 
this compliance time will also allow most operators to accomplish this 
AD during a major maintenance visit. As explained previously, the 
compliance time for the requirements of paragraph (a) of this AD has 
been revised from four years, as proposed, to five years. No other 
change to the final rule has been made in this regard.

Request To Withdraw Proposed Rule

    One commenter requests that the FAA withdraw the proposed rule. The 
commenter asserts that the proposed AD is not warranted. The commenter 
points out that tests conducted by the airplane manufacturer show that 
few lanyards actually failed to hold a ten-pound test load, and those 
that failed had been subjected to relatively harsh environments where 
heat and humidity or use of insecticides or ammonia-based cleaning 
products had been a factor. The commenter states that the inspection 
and replacement of oxygen masks recommended in the service bulletin is 
adequate.
    The FAA does not concur with the commenter's assertion that this AD 
is not warranted. This action is based on an in-flight decompression of 
a Boeing Model 767 series airplane during which about 30 percent of the 
lanyards failed when passengers attempted to use the oxygen masks. 
Investigation revealed that the design of the crimped copper alloy 
ferrules on the lanyards is susceptible to stress corrosion cracking. 
Though environmental factors can accelerate the rate of cracking, the 
FAA finds that such cracking would eventually occur on most masks. The 
FAA acknowledges that many airplanes do not operate in the most severe 
environments; for this reason, a relatively long compliance time has 
been set to allow operators to comply with the requirements of this AD 
during scheduled maintenance. No change to the final rule is necessary 
in this regard.

Request To Remove Certain Airplanes From Applicability Statement

    One commenter requests that the FAA remove Boeing 737-600, -700, 
and -800 series airplanes from the ``Applicability'' statement of the 
proposed rule. The commenter provides no justification for its request. 
The FAA does not concur with the commenter's request. The subject 
oxygen masks could have been installed on these airplanes either during 
production or as spares. No change to the final rule is necessary in 
this regard.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 4,547 Model 737, 757, 767, and 777 series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates 2,206 airplanes of U.S. registry will be affected by this AD.
    For Model 737 series airplanes (approximately 1,334 U.S.-registered 
airplanes), it will take approximately 40 work hours per airplane to 
accomplish the required actions, at the average labor rate of $60 per 
work hour. Required parts will cost approximately $576 per airplane. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $3,969,984, or $2,976 per airplane.
    For Model 757 series airplanes (approximately 558 U.S.-registered 
airplanes), it will take approximately 59 work hours per airplane to 
accomplish the required actions, at the average labor rate of $60 per 
work hour. Required parts will cost approximately $846 per airplane. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $2,447,388, or $4,386 per airplane.
    For Model 767 series airplanes (approximately 280 U.S.-registered 
airplanes), it will take approximately 69 work hours per airplane to 
accomplish the required actions, at the average labor rate of $60 per 
work hour. Required parts will cost approximately $990 per airplane. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $1,436,400, or $5,130 per airplane.
    For Model 777 series airplanes (approximately 34 U.S.-registered 
airplanes), it will take approximately 82 work hours per airplane to 
accomplish the required actions, at the average labor rate of $60 per 
work hour. Required parts will cost approximately $1,170 per airplane. 
Based on these figures, the cost impact of the AD on U.S. operators is 
estimated to be $207,060, or $6,090 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish

[[Page 48367]]

those actions in the future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will 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 final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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.


Sec. 39.13  [Amended]

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

2000-15-16  Boeing: Amendment 39-11848. 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 Bulletin 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 5 years after the effective date of this AD, perform 
a general visual inspection to determine the vendor of all oxygen 
masks in the passenger cabin in accordance with Boeing Service 
Bulletin 737-35-1049, including Appendix A, dated September 17, 1998 
(for Model 737 series airplanes); Boeing Service Bulletin 757-35-
0014, including Appendix A, dated September 10, 1998 (for Model 757 
series airplanes); Boeing Service Bulletin 767-35-0033, including 
Appendix A, dated September 10, 1998 (for Model 767 series 
airplanes); or Boeing Service Bulletin 777-35-0005, including 
Appendix A, dated September 3, 1998, (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.''

    (1) If the oxygen mask is not manufactured by Puritan-Bennett, 
no further action is required by this AD for that mask.
    (2) If the oxygen mask is manufactured by Puritan-Bennett, OR if 
the manufacturer of the mask cannot be identified, prior to further 
flight, perform a general visual inspection to determine the 
manufacturing date of the oxygen mask, in accordance with the 
applicable service bulletin.

Corrective Action

    (b) For each oxygen mask manufactured by Puritan-Bennett or an 
unidentified manufacturer, if the mask was manufactured between May 
1986 and July 1998 inclusive, OR if the manufacturing date cannot be 
determined: Prior to further flight, accomplish either paragraph 
(b)(1) or (b)(2) of this AD.
    (1) Replace the lanyards on the masks with new lanyards in 
accordance with Boeing Service Bulletin 737-35-1049, including 
Appendix A, dated September 17, 1998 (for Model 737 series 
airplanes); 757-35-0014, including Appendix A, dated September 10, 
1998 (for Model 757 series airplanes); 767-35-0033, including 
Appendix A, dated September 10, 1998 (for Model 767 series 
airplanes); or 777-35-0005, including Appendix A, dated September 3, 
1998 (for Model 777 series airplanes); as applicable.
    (2) Replace the existing oxygen mask with a new mask that was 
manufactured by Puritan-Bennett before May 1986 or after July 1998, 
or by another vendor, and that has the same Boeing part number, or 
that is FAA-approved for installation as an alternative to the 
Puritan-Bennett mask.

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.

Incorporation by Reference

    (f) The actions shall be done in accordance with Boeing Service 
Bulletin 737-35-1049, including Appendix A, dated September 17, 1998 
(for Model 737 series airplanes); Boeing Service Bulletin 757-35-
0014, including Appendix A, dated September 10, 1998 (for Model 757 
series airplanes); Boeing Service Bulletin 767-35-0033, including 
Appendix A, dated September 10, 1998 (for Model 767 series 
airplanes); or Boeing Service Bulletin 777-35-0005, including 
Appendix A, dated September 3, 1998 (for Model 777 series 
airplanes); as applicable. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207. Copies may be

[[Page 48368]]

inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (g) This amendment becomes effective on September 12, 2000.

    Issued in Renton, Washington, on July 31, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-19815 Filed 8-7-00; 8:45 am]
BILLING CODE 4910-13-U