Discussion
What events have caused this AD? The FAA has received reports of a potential problem with 8- pole direct current (DC) battery switches that were installed on Cessna Model 525 (CitationJet 1) airplanes. Eaton (located in Sarosota, Florida) is the original equipment manufacturer (OEM) of the affected switch (Eaton part number A3-205-01/P).
Analysis of the problem shows that the switch could fail to make contact or may make intermittent contact. Certain manufacturing lots were assembled using components that were out-of- tolerance. The application of the switch from this lot, as used in the Cessna Model 525 (CitationJet 1) airplanes, could result in any or all of the following failure conditions:
- the pilot could lose power to the "AVN EMER" bus;
- the pilot could become unable to disconnect an overheated ship's NICAD battery. On a battery overheat indication, the AFM instructs the pilot to disconnect the battery and, ifthe problem cannot be fixed, the pilot should immediately land the airplane. The main ship's battery that remains powered in an overheated condition may become hot enough to damage adjacent components and structure and may interfere with continued flight and a safe landing. The FAA classifies this condition as catastrophic; and
- the pilot could lose power to the "EMER" bus.
There is no annunciation feature for these failures and they are only detectable in flight while the pilot requires the use of the applicable function.
What are the consequences if the condition is not corrected? This latent failure could result in the battery switch failing while the airplane is in-flight. This could result in the pilot's inability to select "EMER" power or the inability to disconnect an overheated main ship's battery.
Is there service information that applies to this subject? Cessna has issued Service Bulletin No. SB525-24-20, dated November 16, 2000. This service bulletinincludes procedures for replacing both the DC power battery switch (Eaton part number A3-205-01/P) and the windshield anti-ice bleed air control switch (Eaton part number A3-204-01).
The FAA's Determination and an Explanation of the Provisions of this AD
What has FAA decided? The FAA has reviewed all available information, including the service information referenced above; and determined that:
- the unsafe condition referenced in this document exists or could develop on other Cessna Model 525 (CitationJet 1) airplanes of the same type design;
- the DC power battery switch replacement specified in the previously-referenced service information (as specified in this AD) should be accomplished on the affected airplanes; and
- AD action should be taken in order to correct this unsafe condition. What does this AD require? This AD requires you to replace the DC power battery switch (Eaton part number A3-205-01/P with a manufacturer's date code of 9926 through 0039).Accomplishment of this action is required in accordance with Cessna Service Bulletin No. SB525-24-20, dated November 16, 2000. Are there differences between this AD and the service information? Cessna Service Bulletin No. SB525-24-20, dated November 16, 2000, includes procedures for replacing both the DC power battery switch (Eaton part number A3-205-01/P) and the windshield anti-ice bleed air control switch (Eaton part number A3-204-01).
Failure of the DC power battery switch is latent; the switch can only be tested during a phase check or other maintenance event; and the failure is a safety of flight issue. The anti-ice bleed air control switches are currently checked during preflight and the AFM contains normal emergency procedures should a failure occur in flight. For these reasons, we are only requiring replacement of the DC power battery switch in this AD.
Will I have the opportunity to comment prior to the issuance of the rule? Because the unsafe condition describedin this document could result in the pilot not having power to critical flight components, FAA finds that notice and opportunity for public prior comment are impracticable. Therefore, good cause exists for making this amendment effective in less than 30 days.
Comments Invited
How do I comment on this AD? Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, we invite your comments on the rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments in triplicate to the address specified under the caption "ADDRESSES." We will consider all comments received on or before the closing date specified above. We may amend this rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether we need to take additional rulemaking action.
Are there any specific portions of the AD I should pay attention to? The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. You may examine all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of this AD.
We are reviewing the writing style we currently use in regulatory documents, in response to the Presidential memorandum of June 1, 1998. That memorandum requires federal agencies to communicate more clearly with the public. We are interested in your comments on whether the style of this document is clear, and any other suggestions you might have to improve the clarity of FAA communications that affect you. You can get more information about the Presidential memorandum and the plain language initiative at http://www.plainlanguage.gov.
How can I be sure FAA receives my comment? If you want us to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write "Comments to Docket No. 2000-CE-71-AD." We will date stamp and mail the postcard back to you.
Regulatory Impact
Does this AD impact various entities? These regulations 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, FAA has determined that this final rule does not have federalism implications under Executive Order 13132.
Does this AD involve a significant rule or regulatory action? The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a significant regulatory action under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket (otherwise, an evaluation is not required). A copy of it, if filed, may be obtained from the Rules Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by Reference, Safety.
Adoption of the Amendment
Accordingly, under 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. 39.13 [Amended]
2. FAA amends 39.13 by adding a new airworthiness directive (AD) to read as follows: