These actions are beyond the scope of the action needed to correct this unsafe condition and are not included in this AD. These differences are highlighted in the ``Differences Between the FAA AD and the MCAI'' section of this AD.

FAA's Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because of the risk of oxygen cylinders exploding on board an aircraft and creating a fire hazard. Therefore, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in fewer than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include ``Docket No. FAA20070374; Directorate Identifier 2007SW02AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.

We will post all comments we receive, without change, to http://regulations.gov including any personal information you provide. We will
also post a report summarizing each substantive verbal contact we receive about this AD.

Costs of Compliance

We estimate that this AD will affect about 468 aircraft of U.S. registry. We also estimate that it will take about \1/2\ of a workhour per aircraft to remove the cylinders. The average labor rate is $80 per workhour. Based on these figures, we estimate the cost of this AD on U.S.
[[Page 1970]]
operators to be $4000, assuming that oxygen cylinders are installed on 100 aircraft.

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 Findings

We determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify this AD:

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. 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.

We prepared an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety. Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39AIRWORTHINESS 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. The FAA amends Sec. 39.13 by adding the following new AD: 20072611 Intertechnique Zodiac Aircraft Systems: Amendment 39 15313. Docket No. FAA20070374; Directorate Identifier 2007SW02 AD.
Effective Date
(a) This airworthiness directive (AD) becomes effective January 28, 2008.
Other Affected ADs
(b) None.
Applicability
(c) This AD applies to Intertechnique (F5341), aluminum alloy AA5283, oxygen cylinders manufactured by Societe Metallurgique de Gerzat SAS with GLD series, GLF series, PC2300 or SLF300 part numbers, installed in any aircraft certificated in any category. These oxygen reserve cylinders are installed on but not limited to Model Airbus 300 series; Pilatus P6; Dassault Aviation Mystere Falcon 20, Falcon 50, Falcon 200, and Falcon 900 airplanes; and Eurocopter AS350 and Eurocopter SA315 helicopters.
Reason
(d) The mandatory continued airworthiness information (MCAI) states:

This Airworthiness Directive (AD) is issued following information concerning the risk of highpressure oxygen cylinder tearing with sudden emptying. These cylinders are used for missions at high altitudes or to ensure respiratory air for passengers feeling sick.

It has been demonstrated that the material characteristics of the Aluminum Alloy 5283 (AA5283) from which the cylinders are manufactured deteriorate in the course of time and may possibly lead these oxygen cylinders to tear and abruptly vent aboard an aircraft. Actions and Compliance
(e) Unless already done, remove any affected oxygen reserve cylinder before further flight.
Differences Between the FAA AD and the MCAI
(f) This AD differs from the MCAI as follows:
(1) The MCAI requires removal of the affected oxygen cylinders at specific time intervals; however, this AD requires removal before further flight.
(2) The MCAI requires certain procedures to be used for emptying the cylinders as well as certain action for cylinders held as spares. These actions are beyond the scope of the action needed to correct this unsafe condition and are not included in this AD. Subject
(g) Air Transport Association of America (ATA) Code 3530: Portable Oxygen System.
Other Information
(h) The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, Safety Management Group, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Uday Garadi, Aviation Safety Engineer, Regulations and Guidance Group, Fort Worth, Texas 761930110, telephone (817) 2225123, fax (817) 2225961.
(2) Airworthy Product: Use only FAAapproved corrective actions. Corrective actions are considered FAAapproved if they are approved by the State of Design Authority (or their delegated agent) if the State of Design has an appropriate bilateral agreement with the United States. You are required to assure the product is airworthy before it is returned to service.
(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act, the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120 0056.
Related Information
(i) Mandatory Continuing Airworthiness Information (MCAI) EASA Airworthiness Directive No. 20060286R1, dated March 22, 2007; Intertechnique Service Bulletin No. GLD/GLF35150, dated September 20, 2006; and Eurocopter Alert Service Bulletin Nos. 05.00.54 for the Model AS350B3 and 05.42 for the Model SA315B, both dated August 16, 2006, contain related information.

Issued in Fort Worth, Texas, on December 3, 2007. David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. E725391 Filed 11008; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT Uday Garadi, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Guidance Group, Fort Worth, Texas 761930110, telephone (817) 2225123, fax (817) 2225961.