Airworthiness directives: Boeing,
[Federal Register: January 8, 1999 (Volume 64, Number 5)]
[Rules and Regulations]
[Page 1112-1114]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08ja99-6]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-238-AD; Amendment 39-10981; AD 99-01-16]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
SUMMARY: This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-100, -200, -300, -400, and -500 series airplanes, that requires installation of a placard that warns the cabin crew not to put the selector valve for the forward lavatory water supply in the ``DRAIN'' position during flight. This amendment also requires installation of an isolation valve in the drain line downstream of the selector valve, which would terminate the requirement for the placard installation. This amendment is prompted by reports of damage to the horizontal stabilizer, and engine flameout caused by ice formed from water drained inadvertently through a mispositioned selector valve. The actions specified by this AD are intended to prevent damage to the engines, airframe, or horizontal stabilizer, and/ or to prevent a hazard to persons or property on the ground, as a result of ice that could dislodge from the airplane.
DATES: Effective February 12, 1999.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of February 12, 1999.
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; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Don Eiford, 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) 227-2788; 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 all Boeing Model 737-100, -200, - 300, -400, and -500 series airplanes was published in the Federal Register on November 13, 1997 (62 FR 60810). That action proposed to require installation of a placard that warns the cabin crew not to put the selector valve for the forward lavatory water supply in the ``DRAIN'' position during flight. That action also proposed to require installation of an isolation valve in the drain line downstream of the selector valve.
Consideration of Comments Received
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Request To Delay Issuance of AD Pending Release of Service Information
Several commenters request delay of the issuance of the AD pending the release of appropriate service information that provides technical details for installation of the isolation valve. The commenters state that, without such service information, they are unable to provide meaningful comments regarding the technical content of the proposed AD.
The FAA partially concurs with the commenter's request. The FAA recognizes that a service bulletin would provide technical details and procedures for accomplishing the actions proposed by the notice of proposed rulemaking (NPRM). However, the issue subject to public comment was the general requirement for the placard and valve installations. Further, because the valve installation is not expected to be technically complicated or difficult to accomplish, the FAA does not anticipate receiving any comments addressing the technical aspects of the valve installation. In light of this information, the FAA has determined that it is unnecessary to delay issuance of the final rule.
Request To Revise Applicability
One commenter states its understanding of the applicability as
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being limited to those models on which forward lavatories are installed.
The FAA infers that the commenter is requesting that the FAA revise the applicability to include that limitation. The FAA concurs with the commenter's request, having determined that an affected airplane without a forward lavatory installed would not be subject to the identified unsafe condition. The applicability of the final rule has been revised accordingly.
Request To Consider Valve Installation as Terminating Action
One commenter requests that the proposed AD be revised to require installation initially of either the placard or the valve. That commenter considers the valve installation as the primary solution to address the identified unsafe condition; therefore, valve installation (if accomplished within the compliance time required for the placard installation) would preclude the need for the placard installation. That commenter suggests some airlines may choose to incorporate the valves within the 6-month window and forgo the placard installation. As further justification for its request, the commenter adds that production airplanes now include the isolation valve but not the placard.
The FAA concurs with the request to require installation initially of either the placard or the valve. The FAA's intent behind installation of a placard, as proposed by the NPRM, was to provide an expeditious means to achieve an acceptable level of safety pending installation of the isolation valve. However, the FAA agrees that the isolation valve is considered the primary design solution to the identified unsafe condition. Therefore, the placard would not be needed if the valve is installed within the 6-month compliance time required to install the placard. The final rule has been revised to specify this, and to indicate that installation of the valve terminates the requirement for installation of the placard.
Request To Remove Requirement for Valve Installation
One commenter reports that it has not experienced the problem addressed in the proposed AD. The commenter states that the proposed requirement to install an isolation valve in the drain line is unnecessary, and installation of a placard should be sufficient to address the unsafe condition.
The FAA infers that the commenter is requesting removal of the requirement to install the valve. The FAA does not concur. The FAA has determined that long-term continued operational safety will be better assured by design changes to remove the source of the problem, rather than by reliance on the cabin crew following additional procedures. This determination, coupled with a better understanding of the human factors associated with following such procedures, has led the FAA to consider placing less emphasis on the use of informational placards and more emphasis on design improvements. The valve installation requirement is in consonance with these conditions. No change to the final rule in this regard is necessary.
Concern Regarding AD Effectiveness
One commenter generally supports the proposal, but urges the FAA to continue to monitor occurrences of airframe damage and engine flameout due to inadvertent or erroneous drain valve activation in flight. The commenter states that the proposed corrective action would reduce but not eliminate the possibility of this unsafe condition, and urges the FAA to determine if a more active means of preventing the unsafe condition would be appropriate.
The FAA acknowledges the commenter's concern and will continue to monitor such occurrences of airframe damage and engine flameout. The FAA may consider further rulemaking activity if additional corrective actions are deemed necessary.
Actions Since Issuance of NPRM
Since the issuance of the NPRM, the FAA has reviewed and approved Boeing Service Bulletin 737-38-1043, dated January 8, 1998, which provides procedures for the installation of the placard. Paragraph (a) of the final rule has been revised to incorporate the service bulletin as the appropriate source of service information for the placard installation. In addition, Figure 1 of the NPRM (which depicts the placard) has been removed from the final rule because an appropriate figure is provided in the service bulletin.
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 described previously. 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 2,830 airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,037 airplanes of U.S. registry will be affected by this AD.
It will take approximately 1 work hour per airplane to accomplish the required placard installation, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this installation required by this AD on U.S. operators is estimated to be $62,220, or $60 per airplane.
It will take approximately 6 work hours per airplane to accomplish the required installation of an isolation valve, at an average labor rate of $60 per work hour. Required parts will cost approximately $300 per airplane. Based on these figures, the cost impact of this installation required by this AD on U.S. operators is estimated to be $684,420, or $660 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 those actions in the future if this AD were not adopted.
Regulatory Impact
The regulations adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this section (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 obtain 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.
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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
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
Section 39.13 is amended by adding the following new airworthiness directive:
99-01-16 Boeing: Amendment 39-10981. Docket 97-NM-238-AD.
Applicability: Model 737-100, -200, -300, -400, and -500 series airplanes; having forward lavatories installed; 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 damage to the engines, airframe, or horizontal stabilizer, and/or to prevent a hazard to persons or property on the ground, accomplish the following:
(a) Except as provided by paragraph (c) of this AD: Within 6 months after the effective date of this AD, install a placard on the door beneath the forward lavatory sink, that warns the cabin crew not to put the selector valve for the forward lavatory water supply in the ``DRAIN'' position during flight. The installation shall be accomplished in accordance with Boeing Service Bulletin 737-38-1043, dated January 8, 1998.
(b) Within 36 months after the effective date of this AD, install an isolation valve in the drain line downstream of the selector valve for the forward lavatory water supply, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Once the valve is installed, the placard described in paragraph (a) of this AD may be removed.
(c) For airplanes on which the valve installation required by paragraph (b) of this AD is accomplished within the compliance time specified in paragraph (a) of this AD, the placard installation required by paragraph (a) is not required.
(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 ACO. 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.
(e) Special flight permits may be issued in accordance with sections 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.
(f) The placard installation shall be done in accordance with Boeing Service Bulletin 737-38-1043, dated January 8, 1998. 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 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.
(g) This amendment becomes effective on February 12, 1999.
Issued in Renton, Washington, on December 30, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-185Filed1-7-99; 8:45 am]
BILLING CODE 4910-13-U
