Airworthiness Directives; Boeing Model 747-400, 777-200, and 777-300 Series Airplanes, 1211-1215 [05-286]

Download as PDF 1211 Proposed Rules Federal Register Vol. 70, No. 4 Thursday, January 6, 2005 This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 2000–NM–360–AD] RIN 2120–AA64 Airworthiness Directives; Boeing Model 747–400, 777–200, and 777–300 Series Airplanes Federal Aviation Administration, DOT. ACTION: Supplemental notice of proposed rulemaking; reopening of comment period. AGENCY: This document revises an earlier proposed airworthiness directive (AD), applicable to certain Boeing Model 747–400, 777–200, and 777–300 series airplanes, that would have required, for certain airplanes, replacement of the cell stack of the flight deck humidifier with a suppliertested cell stack, or replacement with an end plate and subsequent deactivation of the flight deck humidifier. For other airplanes, that proposed AD would have required replacement of the cell stack with a blanking plate or a new cell stack, or replacement of the blanking plate with a supplier-tested cell stack. This new action revises the proposed AD by adding airplanes to the applicability; adding new inspections to determine certain part numbers; requiring replacement of the blanking plate with a supplier-tested cell stack if necessary; and changing certain words to clarify the intent of the proposed AD. The actions specified by this new proposed AD are intended to prevent an increased pressure drop across the humidifier and consequent reduced airflow to the flight deck, which could result in the inability to clear any smoke that might appear in the flight deck. This action is intended to address the identified unsafe condition. DATES: Comments must be received by January 31, 2005. SUMMARY: VerDate jul<14>2003 12:18 Jan 05, 2005 Jkt 205001 Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM–114, Attention: Rules Docket No. 2000–NM– 360–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 (425) 227–1232. Comments may also be sent via the Internet using the following address: 9-anmnprmcomment@faa.gov. Comments sent via fax or the Internet must contain ‘‘Docket No. 2000–NM–360–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 or 2000 or ASCII text. The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplanes, PO 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: Jeffrey S. Palmer, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM–150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055–4056; telephone (425) 917–6481; fax (425) 917–6590. SUPPLEMENTARY INFORMATION: ADDRESSES: 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. PO 00000 Frm 00001 Fmt 4702 Sfmt 4702 • 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 2000–NM–360–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. 2000–NM–360–AD, 1601 Lind Avenue, SW., Renton, Washington 98055–4056. Discussion A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to certain Boeing Model 747–400, 777–200, and 777–300 series airplanes, was published as a notice of proposed rulemaking (NPRM) (hereafter referred to as the ‘‘original NPRM’’) in the Federal Register on September 19, 2003 (68 FR 54874). The original NPRM would have required, for certain airplanes, replacement of the cell stack of the flight deck humidifier with a suppliertested cell stack, or replacement with an end plate and subsequent deactivation of the flight deck humidifier. The original NPRM also would have required, for other airplanes, replacement of the cell stack with a blanking plate or a new cell stack, or replacement of the blanking plate with a supplier-tested cell stack. The original NPRM was prompted by reports of sagging cell stack membranes of the flight deck humidifiers. That condition, if not corrected, could result in the E:\FR\FM\06JAP1.SGM 06JAP1 1212 Federal Register / Vol. 70, No. 4 / Thursday, January 6, 2005 / Proposed Rules inability to clear any smoke that might appear in the flight deck. Comments Due consideration has been given to the comments received in response to the original NPRM. Some of the comments, as discussed below, have resulted in changes to the original NPRM. Request To Withdraw the Proposed AD One commenter, the parts manufacturer, requests that the proposed AD be withdrawn. The commenter contends that all affected humidifiers have been screened for the suspect cell stacks. The commenter also notes that it had no ability to track some of the cell stack serial numbers. The FAA does not agree to withdraw the proposed AD. We have not received confirmation that all Model 747–400, 777–200, 777–300 series airplanes equipped with Hamilton Sundstrand flight deck humidifiers have been screened for the suspect cell stacks. Even if the airplanes specified in Boeing Alert Service Bulletin 747–21–A2414, Revision 1, dated October 26, 2000, and Boeing Service Bulletin 777–21A0048, Revision 1, dated September 7, 2000 (referenced as the appropriate sources of service information for accomplishing the proposed actions), were verified not to have a defective cell stack, a defective cell stack could have been installed on certain other airplanes with a Hamilton Sundstrand humidifier. If an airplane not listed in the service bulletin was originally delivered with an acceptable cell stack, it is possible that, through maintenance or replacement actions, a defective cell stack could have been installed on any Model 747–400, 777– 200, or 777–300 airplane with a Hamilton Sundstrand humidifier having part number (P/N) 821486–1 or P/N 816086–1. Based on further review, we have determined that there were approximately 100 flight deck humidifiers produced with the defective cell stack and that 114 airplanes could be fitted with the defective cell stack. Due to the possibility that a defective cell stack could have been installed on any Model 747–400, 777–200, or 777– 300 series airplane equipped with a Hamilton Sundstrand humidifier having P/N 821486–1 or P/N 816086–1, we have added an inspection of Model 747– 400, 777–200, and 777–300 series airplanes equipped with Hamilton Sundstrand flight deck humidifiers to determine if P/N 821486–1 or P/N 816086–1 is installed, and as applicable, an inspection to determine if the cell stack has P/N 821482–1 or P/N 822976– VerDate jul<14>2003 12:18 Jan 05, 2005 Jkt 205001 2. We have added inspections or records reviews to paragraphs (a) and (d) of the supplemental NPRM and revised the other paragraphs accordingly. The applicability of the supplemental NPRM has also been revised to ‘‘Model 747–400, 777–200, 777–300 series airplanes, equipped with Hamilton Sundstrand flight deck humidifiers.’’ In addition, the cost table has been revised to include the cost of the additional inspections and we have revised the number of affected airplanes to 114 worldwide and 29 of U.S. registry. Request To Revise Number of Affected Airplanes of U.S. Registry One commenter, the airplane manufacturer, requests that the number of airplanes of U.S. registry be revised from 12 to none. The commenter notes that the original NPRM specifies there are ‘‘35 airplanes of the affected design in the worldwide fleet. The FAA estimates that 12 airplanes of U.S. registry would be affected by this AD.’’ The commenter states that it has delivered 103 airplanes in production that could be fitted with the cell stack with excessive pressure drop (although only 23 may have been delivered in that configuration). The commenter notes that only one domestic operator has airplanes equipped with Hamilton Sundstrand humidifiers and that this operator cannot have any Model 777 series airplanes having cell stacks with excessive pressure drop. The commenter states the first Model 777 series airplane equipped with a Hamilton Sundstrand humidifier for this operator was the airplane on which the pressure drop discrepancy was discovered, and it was outfitted with a humidifier with an acceptable pressure drop. The commenter goes on to state that this operator’s flight deck humidifier stock is known, and it can be shown that no affected cell stacks exist within that operator’s fleet. Consequently, the commenter believes no airplanes of U.S. registry would be affected by this proposed AD. We do not agree with the commenter’s request to revise the number of airplanes of U.S. registry from 12 to none. As stated in the previous paragraph ‘‘Request to Withdraw the Proposed AD,’’ there is a possibility that a defective cell stack could have been installed on any Model 747–400, 777– 200, or 777–300 series airplane equipped with a Hamilton Sundstrand humidifier having P/N 821486–1 or P/ N 816086–1. Because we have not received confirmation that all Model 747–400, 777–200, 777–300 series airplanes equipped with Hamilton Sundstrand flight deck humidifiers have PO 00000 Frm 00002 Fmt 4702 Sfmt 4702 been screened for the suspect cell stacks, the applicability of the supplemental NPRM has been revised and the number of airplanes of U.S. registry has been revised to 29. Request To Remove ‘‘Replacement of the Blanking Plate With a Supplier Tested Cell Stack’’ Text From Summary and Cost Table One commenter, the airplane manufacturer, requests that in the Summary of the original NPRM, the text ‘‘or replacement of the blanking plate with a supplier tested cell stack’’ be removed and the final row of the cost table in the Cost Impact section be removed. The commenter notes that to mitigate the risk of reduced flight deck airflow the original NPRM requires ‘‘For other airplanes, replacement of the cell stack with a blanking plate or a new cell stack, or replacement of the blanking plate with a supplier-tested cell stack.’’ The commenter states that a risk of reduced airflow to the flight deck does not exist when a blanking plate is installed. We agree that if a blanking plate is installed, reduced airflow to the flight deck will not occur. However, the text ‘‘or replacement of the blanking plate with a supplier-tested cell stack’’ is intended to prevent a discrepant part from being installed on an airplane on which an installed blanking plate is removed and a cell stack is installed. Therefore, in the summary of the supplemental NPRM, for the reasons we are revising the proposed AD, we have added the text ‘‘requiring replacement of the blanking plate with a suppliertested cell stack if necessary’’ in order to clarify the intent of the proposed AD. We have not changed the cost table. Request To Clarify Referenced Requirements The same commenter states that it is unclear which four requirements of paragraph (a)(1) of the original NPRM are being referenced in paragraph (a)(2) of the original NPRM that states ‘‘Replacement of the cell stack with a supplier-tested cell stack in accordance with the 4 requirements of paragraph (a)(1) of this AD * * *’’ We agree that paragraph (b)(2) (specified as paragraph (a)(2) of the original NPRM) should be clarified. The ‘‘4’’ in the ‘‘Replacement of the cell stack * * *’’ sentence was a typographical error. The sentence also should have specified that it was a replacement of the ‘‘end plate’’ and not the ‘‘cell stack.’’ The intent of the sentence was to indicate that the humidifier could be reactivated if the end plate was replaced with a supplier- E:\FR\FM\06JAP1.SGM 06JAP1 1213 Federal Register / Vol. 70, No. 4 / Thursday, January 6, 2005 / Proposed Rules tested cell stack. In addition, the sentence references Part 1 of Boeing Alert Service Bulletin 747–21A2414, Revision 1, dated October 26, 2000, as the relevant source of service information for the replacement. However, Part 1 of the service bulletin does not include procedures for the replacement of the end plate. The replacement of the end plate must be done in a method approved by the FAA. We have revised paragraphs (b) and (b)(2) of the supplemental NPRM and added paragraph (b)(3) of the supplemental NPRM to clarify that there is an option to replace the end plate with a supplier-tested cell stack. Request To Remove Paragraph (c)(3) of the Original NPRM The same commenter also requests removing paragraph (c)(3) of the original NPRM. The commenter states that paragraph (c)(3) concerns replacing a blanking plate with a cell stack. However, the commenter believes this is not necessary, as a humidifier with a blanking plate does not restrict flight deck airflow. The commenter states that this action is not necessary since the risk of reduced airflow to the flight deck does not exist when a blanking plate is installed. We agree with the commenter that reduced airflow to the flight deck does not exist when a blanking plate is installed. However, the purpose of paragraph (e)(3) (specified as paragraph (c)(3) of the original NPRM) of the supplemental NPRM is to prevent a discrepant part from being installed on an airplane if the operator chooses to remove a blanking plate and install a cell stack in its place. Thus, while we do not agree to remove paragraph (e)(3) (specified as paragraph (c)(3) of the original NPRM) of the supplemental NPRM, we have revised the wording in paragraph (e)(3) of the supplemental NPRM to, ‘‘If a blanking plate is removed, and a cell stack installed, the cell stack installation must be done in accordance with Part 3 of the service bulletin.’’ Request to Revise ‘‘Dehumidifier’’ to ‘‘Humidifier’’ The same commenter requests the word ‘‘dehumidifier’’ be revised to ‘‘humidifier.’’ The commenter notes that paragraph (e) of the original NPRM specifies ‘‘flight deck dehumidifier cell stack.’’ The subject of the original NPRM is a humidifier cell stack. We agree with the commenter. Paragraph (g) (specified as paragraph (e) of the original NPRM) of the supplemental NPRM has been revised to specify ‘‘flight deck humidifier cell stack.’’ Request To Revise Reason Given for Sagging Cell Problem The same commenter requests that the cause of the sagging cell problem be changed to ‘‘insufficient rigidity in the cell frame.’’ The commenter notes that the ‘‘Discussion’’ section of the original NPRM states, ‘‘The sagging has been attributed to difficulties encountered during the membrane welding process.’’ The commenter states that the sagging is actually a result of the cell frame material not being rigid. The action taken to correct the sagging cell problem is to change the cell frame material in order to make it more rigid. We agree with the commenter that the sagging is actually a result of the cell frame material not being rigid. However, since the wording from the original NPRM ‘‘the sagging has been attributed to difficulties encountered during the membrane welding process’’ is not restated in the supplemental NPRM, no change is made. Request To Clarify Reason for Increased Pressure The same commenter requests that we clarify when there is an increased pressure drop across the humidifier. Model/series 747–400 777–200 777–300 747–400 747–400 777–200 777–300 777–200 777–300 777–200 777–300 Conclusion Since these changes expand the scope of the originally proposed rule, we have determined that it is necessary to reopen the comment period to provide additional opportunity for public comment. Changes to Delegation Authority Boeing has received a Delegation Option Authorization (DOA). We have revised this supplemental NPRM to delegate the authority to approve an alternative method of compliance for any repair required by this AD to the Authorized Representative for the Boeing DOA Organization rather than the Designated Engineering Representative (DER). Cost Impact There are approximately 114 airplanes of the affected design in the worldwide fleet. The FAA estimates that 29 airplanes of U.S. registry would be affected by this proposed AD. The following cost estimates would vary depending on the actions chosen by the operator. Work hours Action Hourly rate Parts cost Cost per airplane Inspect flight deck humidifier for part number and inspect flight deck humidifier cell stack for part number. 1 $65 $0 $65 Replace cell stack with supplier-tested cell stack ................................................ Replace cell stack with end plate and deactivate humidifier ............................... Replace cell stack with blanking plate .................................................................. 5 6 5 65 65 65 5,100 0 0 5,425 390 325 Replace cell stack with supplier-tested cell stack ................................................ 5 65 6,053 6,378 Replace blanking plate with supplier-tested cell stack ......................................... 3 65 6,053 6,248 The cost impact figures discussed above are based on assumptions that no VerDate jul<14>2003 The commenter notes that the Discussion section of the original NPRM states ‘‘The result of the sagging membrane is an increased pressure drop across the humidifier (if it is activated).’’ The commenter states that the increased pressure drop would exist regardless of whether the humidifier is activated or not. We agree that the increased pressure drop would exist regardless of whether the humidifier is activated or not. Boeing Alert Service Bulletins 747– 21A2412 and 777–21A0048 do not state that the pressure drop occurs only when the humidifier is activated. However, since the Discussion section of the original NPRM is not restated in the supplemental NPRM, no change is made. 12:18 Jan 05, 2005 Jkt 205001 operator has yet accomplished any of the proposed requirements of this AD PO 00000 Frm 00003 Fmt 4702 Sfmt 4702 action, and that no operator would accomplish those actions in the future if E:\FR\FM\06JAP1.SGM 06JAP1 1214 Federal Register / Vol. 70, No. 4 / Thursday, January 6, 2005 / Proposed Rules 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. 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: Authority for This Rulemaking Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency’s authority. We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, ‘‘General requirements.’’ Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. 1. The authority citation for part 39 continues to read as follows: 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. VerDate jul<14>2003 12:18 Jan 05, 2005 Jkt 205001 PART 39—AIRWORTHINESS DIRECTIVES 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 2000–NM–360–AD. Applicability: Model 747–400, 777–200, and 777–300 series airplanes, equipped with a Hamilton Sundstrand flight deck humidifier; certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent an increased pressure drop across the humidifier and consequent reduced airflow to the flight deck, which could result in the inability to clear any smoke that might appear in the flight deck, accomplish the following: Inspections/Records Review: Model 747–400 Series Airplanes (a) For Model 747–400 series airplanes: Within 90 days after the effective date of this AD, inspect the flight deck humidifier to determine whether part number (P/N) 821486–1 is installed. Instead of inspecting the flight deck humidifier, a review of airplane maintenance records is acceptable if the P/N of the flight deck humidifier can be positively determined from that review. (1) If a P/N other than P/N 821486–1 is installed, no further action is required by this paragraph. (2) If P/N 821486–1 is installed, before further flight, inspect the flight deck humidifier cell stack to determine whether P/ N 821482–1 is installed and ‘‘DEV 13433’’ is not marked next to the cell stack part number. Instead of inspecting the flight deck humidifier cell stack, a review of airplane maintenance records is acceptable if the P/N, including whether ‘‘DEV 13433’’ is marked next to the P/N, of the flight deck humidifier cell stack can be positively determined from that review. If ‘‘DEV 13433’’ is marked next to P/N 821482–1, no further action is required by this paragraph. Cell Stack Replacement: Model 747–400 Series Airplanes (b) If during the inspection required by paragraph (a)(2) of this AD, it is determined that the flight deck humidifier cell stack has P/N 821482–1 and does not have ‘‘DEV 13433’’ marked next to the cell stack part number: Before further flight, do the actions specified in paragraph (b)(1), (b)(2), or (b)(3) of this AD. (1) Replace the cell stack of the flight deck humidifier with a supplier-tested cell stack, PO 00000 Frm 00004 Fmt 4702 Sfmt 4702 in accordance with Part 1 of Boeing Alert Service Bulletin 747–21A2414, Revision 1, dated October 26, 2000. (2) Replace the cell stack with an end plate and before further flight deactivate the flight deck humidifier, in accordance with Part 2 of Boeing Alert Service Bulletin 747–21A2414, Revision 1, dated October 26, 2000. (3) If an end plate is removed, and a supplier-tested cell stack installed, the replacement must be done in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the certification basis of the airplane approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a replacement method to be approved, the approval must specifically reference this AD. Replacement of the end plate with a supplier-tested cell stack terminates the requirement to deactivate the flight deck humidifier specified in paragraph (b)(2) of this AD. Note 1: Boeing Alert Service Bulletin 747– 21A2414, Revision 1, dated October 26, 2000, refers to Boeing Service Bulletin 747–21– 2405, Revision 4, dated July 29, 1999, as an additional source of service information for deactivating the humidifier. Note 2: Boeing Alert Service Bulletin 747– 21A2414, Revision 1, dated October 26, 2000, refers to Hamilton Sundstrand Service Bulletins 821486–21–01, dated March 15, 2000, as an additional source of service information for the cell stack replacement. (c) Replacement of the cell stack before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747–21A2414, dated April 13, 2000, is acceptable for compliance with the applicable requirements of paragraphs (b)(1) and (b)(2) of this AD. Inspections/Records Review: Model 777–200 and –300 Series Airplanes (d) For Model 777–200 and 777–300 series airplanes: Within 90 days after the effective date of this AD, inspect the flight deck humidifier to determine if it is P/N 816086– 1. Instead of inspecting the flight deck humidifier, a review of airplane maintenance records is acceptable if the part number P/N of the flight deck humidifier can be positively determined from that review. (1) If a P/N other than P/N 816086–1 is installed, no further action is required by this paragraph. (2) If P/N 816086–1 is installed, before further flight, inspect the flight deck humidifier cell stack to determine whether P/ N 822976–2 is installed and ‘‘DEV 13433’’ is not marked next to the cell stack part number. Instead of inspecting the flight deck humidifier cell stack, a review of airplane maintenance records is acceptable if the P/N, including whether ‘‘DEV 13433’’ is marked next to the P/N, of the flight deck humidifier cell stack can be positively determined from that review. If ‘‘DEV 13433’’ is marked next to P/N 822976–2, no further action is required by this paragraph. E:\FR\FM\06JAP1.SGM 06JAP1 Federal Register / Vol. 70, No. 4 / Thursday, January 6, 2005 / Proposed Rules Cell Stack Replacement: Model 777–200 and –300 Series Airplanes DEPARTMENT OF TRANSPORTATION (e) If during the inspection required by paragraph (d)(2) of this AD, it is determined that the flight deck humidifier cell stack has P/N 822976–2 and does not have ‘‘DEV 13433’’ marked next to the cell stack part number: Before further flight, do the actions specified in paragraph (e)(1), (e)(2), or (e)(3) of this AD, in accordance with Boeing Service Bulletin 777–21A0048, Revision 1, dated September 7, 2000. (1) Replace the cell stack with a blanking plate, in accordance with Part 1 of the service bulletin; and deactivate the humidifier system before further flight in accordance with a method approved by the Manager, Seattle ACO, FAA; or according to data meeting the certification basis of the airplane approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a deactivation method to be approved, the approval must specifically reference this AD. (2) Replace the cell stack with a suppliertested cell stack, in accordance with Part 2 of the service bulletin. (3) If a blanking plate is removed, and a cell stack installed, the cell stack installation must be done in accordance with Part 3 of the service bulletin. Note 3: Boeing Service Bulletin 777– 21A0048, Revision 1, dated September 7, 2000, refers to Hamilton Sundstrand Service Bulletin 816086–21–01, dated March 15, 2000, as an additional source of service information for the cell stack replacement. Federal Aviation Administration (f) On Model 747–400 series airplanes: As of the effective date of this AD, no person may install a flight deck humidifier cell stack having P/N 821482–1, unless ‘‘DEV 13433’’ is also marked next to the cell stack part number. (g) On Model 777–200 and 777–300 series airplanes: As of the effective date of this AD, no person may install a flight deck humidifier cell stack having P/N 822976–2, unless ‘‘DEV 13433’’ is also marked next to the cell stack part number. Alternative Methods of Compliance (h) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, FAA, is authorized to approve alternative methods of compliance for this AD. Issued in Renton, Washington, on December 29, 2004. Kevin M. Mullin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05–286 Filed 1–5–05; 8:45 am] BILLING CODE 4910–13–P 15:05 Jan 05, 2005 [Docket No. FAA–2004–18038; Directorate Identifier 2004–NE–01–AD] Notice of Public Meeting SUMMARY: The Federal Aviation Administration (FAA) will hold a public meeting to gather additional comment and data on a proposed Airworthiness Directive published as a Notice of Proposed Rulemaking (NPRM), Docket Number FAA–2004–18038, (Directorate Identifier 2004–NE–01–AD), in the Federal Register on June 16, 2004. This public meeting will follow the procedure provided in § 11.53 of Title 14 of the Code of Federal Regulations (14 CFR 11.53). DATES: The FAA public meeting will be held February 8, 2005, from 1 p.m. to 5 p.m. ADDRESSES: The FAA public meeting will be held at the Anaheim Convention Center, 800 West Katella Avenue, Anaheim, California, 92802. FOR FURTHER INFORMATION CONTACT: Robert Baitoo, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712–4137; telephone: (562) 627–5245, fax: (562) 627–5210. SUPPLEMENTARY INFORMATION: Background Parts Installation VerDate jul<14>2003 14 CFR Part 39 Jkt 205001 On June 16, 2004, the FAA published in the Federal Register a Notice of Proposed Rulemaking, Docket Number FAA–2004–18038, (Directorate Identifier 2004–NE–01–AD), that proposed a new Airworthiness Directive (AD) Honeywell International Inc., (formerly AlliedSignal, Inc., formerly Textron Lycoming) T5309, T5311, T5313B, T5317A, T5317A–1, and T5317B series turboshaft engines, installed on, but not limited to, Bell 205 and Kaman K–1200 series helicopters, and T53–L–9, T53–L–11, T53–L–13B, T53–L–13BA, T53–L–13B S/SA, T53–L– 13B S/SB, T53–L–13B/D, and T53–L– 703 series turboshaft engines, installed on, but not limited to, Bell AH–1 and UH–1 helicopters, certified under § 21.25 or 21.27 of the Code of Federal Regulations (14 CFR 21.25 or 14 CFR 21.27). As a result of that Notice of Proposed Rulemaking, we received a number of written comments. One commenter requested that we hold a public meeting for the FAA to hear additional information. While the FAA does not generally hold public meetings PO 00000 Frm 00005 Fmt 4702 Sfmt 4702 1215 for proposed Airworthiness Directives, in this case we believe that a nonadversarial, fact-finding proceeding will benefit us. Therefore, we find that the written comments we have received will not allow us to make a fully informed decision on whether to issue a Final Rule, and that a public meeting to hear additional comment on the proposed AD is appropriate. We invite interested persons to attend and present their views to us on specific issues related to this Notice of Proposed Rulemaking. We are particularly interested in hearing from operators of aircraft using T53 turboshaft engines what life limits they are observing for the life-limited rotating components of T53 series turboshaft engines, what cycle counting methods are they practicing, and what mission profile (i.e., logging operation, fire fighting) are they flying. Agenda The purpose of this meeting is to: • (Item 1) Conduct a presentation on the background leading to the Notice of Proposed Rulemaking (NPRM), Docket Number FAA–2004–18038, (Directorate Identifier 2004–NE–01–AD), published in the Federal Register on June 16, 2004. The subject of the NPRM is FAAapproved life limits for the life limited rotating components including those made of D979 material, installed in Honeywell (formerly AlliedSignal, formerly Lycoming) T53 series turboshaft engines. • (Item 2) Invite the interested persons to present their views to the FAA regarding the NPRM. • (Item 3) Ask the operators of T53 series turboshaft engine powered helicopters what life limits they are observing for the life-limited rotating components of T53 series turboshaft engines, what cycle counting methods are they practicing; and what mission profile (i.e., logging operation, fire fighting) are they flying. Procedure The meeting will be held using the procedure provided in § 11.53 of Title 14 of the Code of Federal Regulations (14 CFR 11.53). The meeting will be open to the public, non-adversarial, and be conducted by a representative of the FAA. In addition, each person desiring to make a presentation must either notify us in advance of the meeting by contacting Robert Baitoo (see FOR FURTHER INFORMATION CONTACT), or by signing the registers that will be available immediately preceding the meeting at the meeting location. Those persons who have registered in advance or at the door will be invited to speak first. If any time remains after all E:\FR\FM\06JAP1.SGM 06JAP1

Agencies

[Federal Register Volume 70, Number 4 (Thursday, January 6, 2005)]
[Proposed Rules]
[Pages 1211-1215]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-286]

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Proposed Rules
Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 70, No. 4 / Thursday, January 6, 2005 /
Proposed Rules

[[Page 1211]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-360-AD]
RIN 2120-AA64

Airworthiness Directives; Boeing Model 747-400, 777-200, and 777-
300 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness
directive (AD), applicable to certain Boeing Model 747-400, 777-200,
and 777-300 series airplanes, that would have required, for certain
airplanes, replacement of the cell stack of the flight deck humidifier
with a supplier-tested cell stack, or replacement with an end plate and
subsequent deactivation of the flight deck humidifier. For other
airplanes, that proposed AD would have required replacement of the cell
stack with a blanking plate or a new cell stack, or replacement of the
blanking plate with a supplier-tested cell stack. This new action
revises the proposed AD by adding airplanes to the applicability;
adding new inspections to determine certain part numbers; requiring
replacement of the blanking plate with a supplier-tested cell stack if
necessary; and changing certain words to clarify the intent of the
proposed AD. The actions specified by this new proposed AD are intended
to prevent an increased pressure drop across the humidifier and
consequent reduced airflow to the flight deck, which could result in
the inability to clear any smoke that might appear in the flight deck.
This action is intended to address the identified unsafe condition.

DATES: Comments must be received by January 31, 2005.

ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2000-NM-360-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 (425) 227-1232.
Comments may also be sent via the Internet using the following address:
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must
contain ``Docket No. 2000-NM-360-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 or 2000 or
ASCII text.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplanes, PO 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: Jeffrey S. Palmer, Aerospace Engineer,
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 917-6481; fax (425) 917-6590.

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 2000-NM-360-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. 2000-NM-360-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to add an airworthiness directive (AD), applicable to
certain Boeing Model 747-400, 777-200, and 777-300 series airplanes,
was published as a notice of proposed rulemaking (NPRM) (hereafter
referred to as the ``original NPRM'') in the Federal Register on
September 19, 2003 (68 FR 54874). The original NPRM would have
required, for certain airplanes, replacement of the cell stack of the
flight deck humidifier with a supplier-tested cell stack, or
replacement with an end plate and subsequent deactivation of the flight
deck humidifier. The original NPRM also would have required, for other
airplanes, replacement of the cell stack with a blanking plate or a new
cell stack, or replacement of the blanking plate with a supplier-tested
cell stack. The original NPRM was prompted by reports of sagging cell
stack membranes of the flight deck humidifiers. That condition, if not
corrected, could result in the

[[Page 1212]]

inability to clear any smoke that might appear in the flight deck.

Comments

Due consideration has been given to the comments received in
response to the original NPRM. Some of the comments, as discussed
below, have resulted in changes to the original NPRM.

Request To Withdraw the Proposed AD

One commenter, the parts manufacturer, requests that the proposed
AD be withdrawn. The commenter contends that all affected humidifiers
have been screened for the suspect cell stacks. The commenter also
notes that it had no ability to track some of the cell stack serial
numbers.
The FAA does not agree to withdraw the proposed AD. We have not
received confirmation that all Model 747-400, 777-200, 777-300 series
airplanes equipped with Hamilton Sundstrand flight deck humidifiers
have been screened for the suspect cell stacks. Even if the airplanes
specified in Boeing Alert Service Bulletin 747-21-A2414, Revision 1,
dated October 26, 2000, and Boeing Service Bulletin 777-21A0048,
Revision 1, dated September 7, 2000 (referenced as the appropriate
sources of service information for accomplishing the proposed actions),
were verified not to have a defective cell stack, a defective cell
stack could have been installed on certain other airplanes with a
Hamilton Sundstrand humidifier. If an airplane not listed in the
service bulletin was originally delivered with an acceptable cell
stack, it is possible that, through maintenance or replacement actions,
a defective cell stack could have been installed on any Model 747-400,
777-200, or 777-300 airplane with a Hamilton Sundstrand humidifier
having part number (P/N) 821486-1 or P/N 816086-1.
Based on further review, we have determined that there were
approximately 100 flight deck humidifiers produced with the defective
cell stack and that 114 airplanes could be fitted with the defective
cell stack.
Due to the possibility that a defective cell stack could have been
installed on any Model 747-400, 777-200, or 777-300 series airplane
equipped with a Hamilton Sundstrand humidifier having P/N 821486-1 or
P/N 816086-1, we have added an inspection of Model 747-400, 777-200,
and 777-300 series airplanes equipped with Hamilton Sundstrand flight
deck humidifiers to determine if P/N 821486-1 or P/N 816086-1 is
installed, and as applicable, an inspection to determine if the cell
stack has P/N 821482-1 or P/N 822976-2. We have added inspections or
records reviews to paragraphs (a) and (d) of the supplemental NPRM and
revised the other paragraphs accordingly.
The applicability of the supplemental NPRM has also been revised to
``Model 747-400, 777-200, 777-300 series airplanes, equipped with
Hamilton Sundstrand flight deck humidifiers.'' In addition, the cost
table has been revised to include the cost of the additional
inspections and we have revised the number of affected airplanes to 114
worldwide and 29 of U.S. registry.

Request To Revise Number of Affected Airplanes of U.S. Registry

One commenter, the airplane manufacturer, requests that the number
of airplanes of U.S. registry be revised from 12 to none. The commenter
notes that the original NPRM specifies there are ``35 airplanes of the
affected design in the worldwide fleet. The FAA estimates that 12
airplanes of U.S. registry would be affected by this AD.'' The
commenter states that it has delivered 103 airplanes in production that
could be fitted with the cell stack with excessive pressure drop
(although only 23 may have been delivered in that configuration). The
commenter notes that only one domestic operator has airplanes equipped
with Hamilton Sundstrand humidifiers and that this operator cannot have
any Model 777 series airplanes having cell stacks with excessive
pressure drop. The commenter states the first Model 777 series airplane
equipped with a Hamilton Sundstrand humidifier for this operator was
the airplane on which the pressure drop discrepancy was discovered, and
it was outfitted with a humidifier with an acceptable pressure drop.
The commenter goes on to state that this operator's flight deck
humidifier stock is known, and it can be shown that no affected cell
stacks exist within that operator's fleet. Consequently, the commenter
believes no airplanes of U.S. registry would be affected by this
proposed AD.
We do not agree with the commenter's request to revise the number
of airplanes of U.S. registry from 12 to none. As stated in the
previous paragraph ``Request to Withdraw the Proposed AD,'' there is a
possibility that a defective cell stack could have been installed on
any Model 747-400, 777-200, or 777-300 series airplane equipped with a
Hamilton Sundstrand humidifier having P/N 821486-1 or P/N 816086-1.
Because we have not received confirmation that all Model 747-400, 777-
200, 777-300 series airplanes equipped with Hamilton Sundstrand flight
deck humidifiers have been screened for the suspect cell stacks, the
applicability of the supplemental NPRM has been revised and the number
of airplanes of U.S. registry has been revised to 29.

Request To Remove ``Replacement of the Blanking Plate With a Supplier
Tested Cell Stack'' Text From Summary and Cost Table

One commenter, the airplane manufacturer, requests that in the
Summary of the original NPRM, the text ``or replacement of the blanking
plate with a supplier tested cell stack'' be removed and the final row
of the cost table in the Cost Impact section be removed. The commenter
notes that to mitigate the risk of reduced flight deck airflow the
original NPRM requires ``For other airplanes, replacement of the cell
stack with a blanking plate or a new cell stack, or replacement of the
blanking plate with a supplier-tested cell stack.'' The commenter
states that a risk of reduced airflow to the flight deck does not exist
when a blanking plate is installed.
We agree that if a blanking plate is installed, reduced airflow to
the flight deck will not occur. However, the text ``or replacement of
the blanking plate with a supplier-tested cell stack'' is intended to
prevent a discrepant part from being installed on an airplane on which
an installed blanking plate is removed and a cell stack is installed.
Therefore, in the summary of the supplemental NPRM, for the reasons we
are revising the proposed AD, we have added the text ``requiring
replacement of the blanking plate with a supplier-tested cell stack if
necessary'' in order to clarify the intent of the proposed AD. We have
not changed the cost table.

Request To Clarify Referenced Requirements

The same commenter states that it is unclear which four
requirements of paragraph (a)(1) of the original NPRM are being
referenced in paragraph (a)(2) of the original NPRM that states
``Replacement of the cell stack with a supplier-tested cell stack in
accordance with the 4 requirements of paragraph (a)(1) of this AD * *
*''
We agree that paragraph (b)(2) (specified as paragraph (a)(2) of
the original NPRM) should be clarified. The ``4'' in the ``Replacement
of the cell stack * * *'' sentence was a typographical error. The
sentence also should have specified that it was a replacement of the
``end plate'' and not the ``cell stack.'' The intent of the sentence
was to indicate that the humidifier could be reactivated if the end
plate was replaced with a supplier-

[[Page 1213]]

tested cell stack. In addition, the sentence references Part 1 of
Boeing Alert Service Bulletin 747-21A2414, Revision 1, dated October
26, 2000, as the relevant source of service information for the
replacement. However, Part 1 of the service bulletin does not include
procedures for the replacement of the end plate. The replacement of the
end plate must be done in a method approved by the FAA. We have revised
paragraphs (b) and (b)(2) of the supplemental NPRM and added paragraph
(b)(3) of the supplemental NPRM to clarify that there is an option to
replace the end plate with a supplier-tested cell stack.

Request To Remove Paragraph (c)(3) of the Original NPRM

The same commenter also requests removing paragraph (c)(3) of the
original NPRM. The commenter states that paragraph (c)(3) concerns
replacing a blanking plate with a cell stack. However, the commenter
believes this is not necessary, as a humidifier with a blanking plate
does not restrict flight deck airflow. The commenter states that this
action is not necessary since the risk of reduced airflow to the flight
deck does not exist when a blanking plate is installed.
We agree with the commenter that reduced airflow to the flight deck
does not exist when a blanking plate is installed. However, the purpose
of paragraph (e)(3) (specified as paragraph (c)(3) of the original
NPRM) of the supplemental NPRM is to prevent a discrepant part from
being installed on an airplane if the operator chooses to remove a
blanking plate and install a cell stack in its place. Thus, while we do
not agree to remove paragraph (e)(3) (specified as paragraph (c)(3) of
the original NPRM) of the supplemental NPRM, we have revised the
wording in paragraph (e)(3) of the supplemental NPRM to, ``If a
blanking plate is removed, and a cell stack installed, the cell stack
installation must be done in accordance with Part 3 of the service
bulletin.''

Request to Revise ``Dehumidifier'' to ``Humidifier''

The same commenter requests the word ``dehumidifier'' be revised to
``humidifier.'' The commenter notes that paragraph (e) of the original
NPRM specifies ``flight deck dehumidifier cell stack.'' The subject of
the original NPRM is a humidifier cell stack.
We agree with the commenter. Paragraph (g) (specified as paragraph
(e) of the original NPRM) of the supplemental NPRM has been revised to
specify ``flight deck humidifier cell stack.''

Request To Revise Reason Given for Sagging Cell Problem

The same commenter requests that the cause of the sagging cell
problem be changed to ``insufficient rigidity in the cell frame.'' The
commenter notes that the ``Discussion'' section of the original NPRM
states, ``The sagging has been attributed to difficulties encountered
during the membrane welding process.'' The commenter states that the
sagging is actually a result of the cell frame material not being
rigid. The action taken to correct the sagging cell problem is to
change the cell frame material in order to make it more rigid.
We agree with the commenter that the sagging is actually a result
of the cell frame material not being rigid. However, since the wording
from the original NPRM ``the sagging has been attributed to
difficulties encountered during the membrane welding process'' is not
restated in the supplemental NPRM, no change is made.

Request To Clarify Reason for Increased Pressure

The same commenter requests that we clarify when there is an
increased pressure drop across the humidifier. The commenter notes that
the Discussion section of the original NPRM states ``The result of the
sagging membrane is an increased pressure drop across the humidifier
(if it is activated).'' The commenter states that the increased
pressure drop would exist regardless of whether the humidifier is
activated or not.
We agree that the increased pressure drop would exist regardless of
whether the humidifier is activated or not. Boeing Alert Service
Bulletins 747-21A2412 and 777-21A0048 do not state that the pressure
drop occurs only when the humidifier is activated. However, since the
Discussion section of the original NPRM is not restated in the
supplemental NPRM, no change is made.

Conclusion

Since these changes expand the scope of the originally proposed
rule, we have determined that it is necessary to reopen the comment
period to provide additional opportunity for public comment.

Changes to Delegation Authority

Boeing has received a Delegation Option Authorization (DOA). We
have revised this supplemental NPRM to delegate the authority to
approve an alternative method of compliance for any repair required by
this AD to the Authorized Representative for the Boeing DOA
Organization rather than the Designated Engineering Representative
(DER).

Cost Impact

There are approximately 114 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 29 airplanes of U.S. registry
would be affected by this proposed AD. The following cost estimates
would vary depending on the actions chosen by the operator.

----------------------------------------------------------------------------------------------------------------
Work Hourly Parts Cost per
Model/series Action hours rate cost airplane
----------------------------------------------------------------------------------------------------------------
747-400 Inspect flight deck humidifier for 1 $65 $0 $65
777-200 part number and inspect flight
777-300 deck humidifier cell stack for
part number.
747-400 Replace cell stack with supplier- 5 65 5,100 5,425
tested cell stack.
747-400 Replace cell stack with end plate 6 65 0 390
and deactivate humidifier.
777-200 Replace cell stack with blanking 5 65 0 325
777-300 plate.
777-200 Replace cell stack with supplier- 5 65 6,053 6,378
777-300 tested cell stack.
777-200 Replace blanking plate with 3 65 6,053 6,248
777-300 supplier-tested cell stack.
----------------------------------------------------------------------------------------------------------------

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

[[Page 1214]]

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.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, Section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.

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.

Sec. 39.13 [Amended]

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

Boeing: Docket 2000-NM-360-AD.

Applicability: Model 747-400, 777-200, and 777-300 series
airplanes, equipped with a Hamilton Sundstrand flight deck
humidifier; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent an increased pressure drop across the humidifier and
consequent reduced airflow to the flight deck, which could result in
the inability to clear any smoke that might appear in the flight
deck, accomplish the following:

Inspections/Records Review: Model 747-400 Series Airplanes

(a) For Model 747-400 series airplanes: Within 90 days after the
effective date of this AD, inspect the flight deck humidifier to
determine whether part number (P/N) 821486-1 is installed. Instead
of inspecting the flight deck humidifier, a review of airplane
maintenance records is acceptable if the P/N of the flight deck
humidifier can be positively determined from that review.
(1) If a P/N other than P/N 821486-1 is installed, no further
action is required by this paragraph.
(2) If P/N 821486-1 is installed, before further flight, inspect
the flight deck humidifier cell stack to determine whether P/N
821482-1 is installed and ``DEV 13433'' is not marked next to the
cell stack part number. Instead of inspecting the flight deck
humidifier cell stack, a review of airplane maintenance records is
acceptable if the P/N, including whether ``DEV 13433'' is marked
next to the P/N, of the flight deck humidifier cell stack can be
positively determined from that review. If ``DEV 13433'' is marked
next to P/N 821482-1, no further action is required by this
paragraph.

Cell Stack Replacement: Model 747-400 Series Airplanes

(b) If during the inspection required by paragraph (a)(2) of
this AD, it is determined that the flight deck humidifier cell stack
has P/N 821482-1 and does not have ``DEV 13433'' marked next to the
cell stack part number: Before further flight, do the actions
specified in paragraph (b)(1), (b)(2), or (b)(3) of this AD.
(1) Replace the cell stack of the flight deck humidifier with a
supplier-tested cell stack, in accordance with Part 1 of Boeing
Alert Service Bulletin 747-21A2414, Revision 1, dated October 26,
2000.
(2) Replace the cell stack with an end plate and before further
flight deactivate the flight deck humidifier, in accordance with
Part 2 of Boeing Alert Service Bulletin 747-21A2414, Revision 1,
dated October 26, 2000.
(3) If an end plate is removed, and a supplier-tested cell stack
installed, the replacement must be done in accordance with a method
approved by the Manager, Seattle Aircraft Certification Office
(ACO), FAA; or according to data meeting the certification basis of
the airplane approved by an Authorized Representative for the Boeing
Delegation Option Authorization Organization who has been authorized
by the Manager, Seattle ACO, to make those findings. For a
replacement method to be approved, the approval must specifically
reference this AD. Replacement of the end plate with a supplier-
tested cell stack terminates the requirement to deactivate the
flight deck humidifier specified in paragraph (b)(2) of this AD.

Note 1: Boeing Alert Service Bulletin 747-21A2414, Revision 1,
dated October 26, 2000, refers to Boeing Service Bulletin 747-21-
2405, Revision 4, dated July 29, 1999, as an additional source of
service information for deactivating the humidifier.

Note 2: Boeing Alert Service Bulletin 747-21A2414, Revision 1,
dated October 26, 2000, refers to Hamilton Sundstrand Service
Bulletins 821486-21-01, dated March 15, 2000, as an additional
source of service information for the cell stack replacement.

(c) Replacement of the cell stack before the effective date of
this AD in accordance with Boeing Alert Service Bulletin 747-
21A2414, dated April 13, 2000, is acceptable for compliance with the
applicable requirements of paragraphs (b)(1) and (b)(2) of this AD.

Inspections/Records Review: Model 777-200 and -300 Series Airplanes

(d) For Model 777-200 and 777-300 series airplanes: Within 90
days after the effective date of this AD, inspect the flight deck
humidifier to determine if it is P/N 816086-1. Instead of inspecting
the flight deck humidifier, a review of airplane maintenance records
is acceptable if the part number P/N of the flight deck humidifier
can be positively determined from that review.
(1) If a P/N other than P/N 816086-1 is installed, no further
action is required by this paragraph.
(2) If P/N 816086-1 is installed, before further flight, inspect
the flight deck humidifier cell stack to determine whether P/N
822976-2 is installed and ``DEV 13433'' is not marked next to the
cell stack part number. Instead of inspecting the flight deck
humidifier cell stack, a review of airplane maintenance records is
acceptable if the P/N, including whether ``DEV 13433'' is marked
next to the P/N, of the flight deck humidifier cell stack can be
positively determined from that review. If ``DEV 13433'' is marked
next to P/N 822976-2, no further action is required by this
paragraph.

[[Page 1215]]

Cell Stack Replacement: Model 777-200 and -300 Series Airplanes

(e) If during the inspection required by paragraph (d)(2) of
this AD, it is determined that the flight deck humidifier cell stack
has P/N 822976-2 and does not have ``DEV 13433'' marked next to the
cell stack part number: Before further flight, do the actions
specified in paragraph (e)(1), (e)(2), or (e)(3) of this AD, in
accordance with Boeing Service Bulletin 777-21A0048, Revision 1,
dated September 7, 2000.
(1) Replace the cell stack with a blanking plate, in accordance
with Part 1 of the service bulletin; and deactivate the humidifier
system before further flight in accordance with a method approved by
the Manager, Seattle ACO, FAA; or according to data meeting the
certification basis of the airplane approved by an Authorized
Representative for the Boeing Delegation Option Authorization
Organization who has been authorized by the Manager, Seattle ACO, to
make those findings. For a deactivation method to be approved, the
approval must specifically reference this AD.
(2) Replace the cell stack with a supplier-tested cell stack, in
accordance with Part 2 of the service bulletin.
(3) If a blanking plate is removed, and a cell stack installed,
the cell stack installation must be done in accordance with Part 3
of the service bulletin.

Note 3: Boeing Service Bulletin 777-21A0048, Revision 1, dated
September 7, 2000, refers to Hamilton Sundstrand Service Bulletin
816086-21-01, dated March 15, 2000, as an additional source of
service information for the cell stack replacement.

Parts Installation

(f) On Model 747-400 series airplanes: As of the effective date
of this AD, no person may install a flight deck humidifier cell
stack having P/N 821482-1, unless ``DEV 13433'' is also marked next
to the cell stack part number.
(g) On Model 777-200 and 777-300 series airplanes: As of the
effective date of this AD, no person may install a flight deck
humidifier cell stack having P/N 822976-2, unless ``DEV 13433'' is
also marked next to the cell stack part number.

Alternative Methods of Compliance

(h) In accordance with 14 CFR 39.19, the Manager, Seattle ACO,
FAA, is authorized to approve alternative methods of compliance for
this AD.

Issued in Renton, Washington, on December 29, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-286 Filed 1-5-05; 8:45 am]
BILLING CODE 4910-13-P

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