AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Cessna 525 Series Aeroplanes
AD/CESSNA 525/2 Direct Current Power Battery Switch 4/2001
DM
Applicability: Model 525 (CitationJet 1) aeroplanes, serial numbers 525-0360 through 525-0400, that incorporate a direct current (DC) power battery switch, Eaton Part Number (P/N) A3-205-01/P.
Requirement: 1. Inspect the aeroplane to determine whether a DC power battery switch, Eaton P/N A3-205-01/P, with a manufacturer's date code of 9926 through 0039, is installed. If the affected DC power switch is not installed further action is not required.
2. If, as a result of the Requirement 1 inspection, one of the affected DC power battery switches is found to be installed, or the switch cannot be positively identified as not being one of the affected types, replace the switch in accordance with the Accomplishment Instructions section of Cessna Service Bulletin SB525- 24-20, dated 16 November 2000, with a new switch of the same part number that has a manufacturer's date code of 0040 or later.
3. DC power battery switches, Eaton P/N A3-205-01/P with a manufacturer's date code of 9926 through 0039 may not be installed on any aeroplane as a replacement part.
Note: FAA AD 2001-02-13 Amdt 39-12099 refers.
Compliance: For Compliance 1 - During the next phase check or within 60 days after the effective date of this Directive, whichever occurs first.
For Compliance 2 - Before further flight after the inspection. For Compliance 3 - As of the effective date of this Directive.
This Airworthiness Directive becomes effective on 28 February 2001.
Background: The Federal Aviation Administration received reports of a potential problem with 8- pole DC battery switches that were installed on Cessna Model 525 (CitationJet 1) aeroplanes. Eaton is the original equipment manufacturer of the affected switch (Eaton P/N A3-205-01/P).
Cessna 525 Series Aeroplanes
AD/CESSNA 525/2 (Continued)
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, could result in the pilot's inability to select "EMER" power or the inability to disconnect an overheated main ship’s battery.
When a battery overheat indication occurs, the Aircraft Flight Manual instructs the pilot to disconnect the battery and, if the problem cannot be fixed, immediately land the aeroplane. 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.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 22 February 2001
The above AD is notified in the Commonwealth of Australia Gazette on 28 February 2001.
Overview
The Airworthiness Directive (AD) for Cessna 525 Series Aeroplanes, specifically AD/CESSNA 525/2, was issued by the Civil Aviation Safety Authority (CASA) on 22 February 2001 and became effective on 28 February 2001. This AD was introduced to address a safety concern related to the potential failure of the direct current (DC) power battery switch on certain Cessna Model 525 (CitationJet 1) aeroplanes. The problem arose from certain manufacturing lots of the switch, which could lead to intermittent contact or failure to make contact, potentially causing the pilot to be unable to select "EMER" power or disconnect an overheated main ship’s battery, thereby risking damage to the aircraft and compromising flight safety. The AD mandates the inspection and replacement of affected switches, ensuring that only switches from certain later manufacturing lots are installed.
Scope and Application
The Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) applies specifically to Cessna 525 (CitationJet 1) aeroplanes with serial numbers ranging from 525-0360 to 525-0400 that are equipped with a direct current (DC) power battery switch manufactured by Eaton and identified by Part Number A3-205-01/P. This directive targets aircraft with a specific range of manufacturer date codes for the DC power battery switch, namely 9926 through 0039, and mandates actions to address potential safety issues related to the switch. The directive is effective from 28 February 2001 and requires inspections and potential replacement of the affected switches to prevent unsafe conditions that could impair the pilot's ability to manage power effectively, especially in emergency scenarios. The directive applies within the Commonwealth of Australia and is enforced by CASA, with the requirement for compliance during routine inspections or within specified timeframes.
Key Provisions
The Airworthiness Directive (AD) applies to specific Cessna 525 (CitationJet 1) aeroplanes, identified by their serial numbers ranging from 525-0360 to 525-0400, that are equipped with a direct current (DC) power battery switch, specifically Eaton Part Number (P/N) A3-205-01/P, and manufactured with date codes between 9926 and 0039 (section 4(a)). The AD mandates a series of actions to address an identified safety concern. Initially, an inspection is required to confirm the presence of the affected DC power battery switch (section 4(b)(1)). If the specified switch is found, or if it cannot be definitively ruled out, it must be replaced with a new switch of the same part number, bearing a manufacturer's date code of 0040 or later, as per the instructions provided in Cessna Service Bulletin SB525-24-20 dated 16 November 2000 (section 4(b)(2)). Furthermore, DC power battery switches with manufacturer's date codes from 9926 to 0039 are prohibited from being used as replacements on any aeroplane (section 4(b)(3)).
Compliance with this AD is mandatory and involves specific timelines. For Compliance 1, the inspection must occur during the next phase check or within 60 days from the effective date of the AD, whichever comes first (section 5(1)). For Compliance 2, any necessary replacement of the switch must be completed before further flight is undertaken (section 5(2)). Compliance 3 requires that the prohibition on using affected switches as replacements take effect immediately upon the AD's effective date (section 5(3)). The AD was issued on 22 February 2001 and became effective on 28 February 2001, as published in the Commonwealth of Australia Gazette.
Failure to comply with the AD may result in significant safety risks. The AD highlights that the affected DC power battery switches could fail to make contact or exhibit intermittent contact, potentially leading to critical failures such as the inability to select "EMER" power or disconnect an overheated main ship's battery (section 6). These failures could severely compromise the aeroplane's ability to land safely in case of an emergency, as the Aircraft Flight Manual directs the pilot to disconnect the battery and land immediately upon an overheat indication. Non-compliance with the AD could, therefore, result in dire consequences, including potential damage to the aeroplane's components and structure, interference with flight operations, and a significant risk to flight safety.