AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/LJ60/1 and issues the following AD under subregulation 39.1 (1) of CASR 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.
Learjet 60 Series Aeroplanes
AD/LJ60/1
Amdt 1
Abnormal Brake Wear Condition 7/2004
Applicability: Model 60 aircraft, equipped with Aircraft Braking Systems (ABS) brake assembly part number 5003096-7.
Requirement: 1. Measure the brake wear dimension between the housing sub-assembly and the pressure plate that is adjacent to the top pistons of the brake assembly, in accordance with ABS Service Bulletin LEAR60-32-03, dated 5 March 1998.
- If the dimension is less than 0.344 inches (8.74 mm), thereafter, repeat the measurement.
b. If the dimension is equal to or greater than 0.344 inches (8.74 mm), thereafter, repeat the measurement.
c. If the dimension is equal to or greater than 0.359 inches (9.12 mm) and less than 0.464 inches (11.79 mm), perform a visual inspection to detect abnormal wear of the friction mix on the rotating discs, in accordance with the Requirement document.
(i) If the friction mix is not worn to the disc cores on either disc, thereafter, repeat the measurement.
(ii) If the friction mix is worn to the disc core on either disc, replace both rotating discs with new discs in accordance with the Requirement document. Thereafter, repeat the measurement.
d. If the dimension is greater than or equal to 0.464 inches (11.79 mm), replace the disc stack with a new disc stack, or overhaul it; in accordance with the Requirement document. Thereafter, repeat the measurement.
2. A used ABS part number 5003096-7 brake assembly shall not be installed on any aircraft, unless it has been inspected and applicable corrective actions have been performed in accordance with the requirements of this Directive.
Note: FAA AD 98-16-18 Amdt 39-10694 refers.
Learjet 60 Series Aeroplanes
AD/LJ60/1 Amdt 1 (continued)
Compliance: 1. For brakes which have accumulated more than 100 cycles since new, accomplish within 10 flight hours after the effective date of this AD, unless the initial check is already accomplished. No inspection is required for brakes with less than 100 cycles accumulated.
- At intervals not to exceed 35 flight cycles.
b. At intervals not to exceed 25 flight cycles.
c. (i). Repeat at intervals not to exceed 25 flight cycles.
(ii). Before further flight. Subsequent repeat inspections are to be carried out in accordance with an initial threshold and repeat interval appropriate for new brakes, i.e. begin again from part 1 of this AD
d. Before further flight. Subsequent repeat inspections are to be carried out in accordance with an initial threshold and repeat interval appropriate for new brakes, i.e. begin again from part 1 of this AD.
2. As of the effective date of this Directive.
This Amendment becomes effective on 8 July 2004.
Background: This AD was raised in response to the release of an FAA AD that was issued after reports of abnormal (uneven) brake wear.
This amendment changes the compliance to reflect the compliance allowed in FAA letter of dispensation to the Danish LDD. Refer to FAA letter of dispensation, LDD 2000-099-047, dated November 12, 1998.
David Villiers
Delegate of the Civil Aviation Safety Authority 26 May 2004
The above AD is notified in the Commonwealth of Australia Gazette on 16 June 2004.
Overview
The Civil Aviation Safety Authority (CASA) issued the Airworthiness Directive (AD) AD/LJ60/1 Amdt 1 on 26 May 2004, revoking the previous AD AD/LJ60/1 to address abnormal brake wear issues on Learjet 60 Series Aeroplanes equipped with Aircraft Braking Systems (ABS) brake assembly part number 5003096-7. This directive was enacted under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998, aiming to correct an unsafe condition identified in the braking systems of these aircraft. The AD was issued in response to reports of uneven brake wear, which prompted the Federal Aviation Administration (FAA) to issue its own AD. The policy objective of this directive is to ensure that corrective actions are taken to prevent unsafe conditions related to brake wear, thereby enhancing the safety of the aircraft. The AD specifies requirements for measuring brake wear and performing corrective actions based on the measured dimensions, as well as prohibiting the installation of used brake assemblies without proper inspection and corrective actions.
Scope and Application
The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998, pertains specifically to the Learjet 60 Series aeroplanes equipped with Aircraft Braking Systems (ABS) brake assembly part number 5003096-7. This legislation applies to the Model 60 aircraft that have this particular ABS brake assembly, focusing on rectifying unsafe conditions related to abnormal brake wear. The requirement outlined in the AD mandates that specific measurements and inspections of the brake wear dimensions be conducted in accordance with ABS Service Bulletin LEAR60-32-03, dated 5 March 1998. Depending on the measurement outcomes, actions such as visual inspections, replacement of rotating discs, or overhauling of the disc stack must be taken to address identified issues. Additionally, used ABS brake assemblies must be inspected and any necessary corrective actions performed before installation on any aircraft. Compliance with this AD requires inspections within specific timeframes related to the number of accumulated flight cycles since new, with intervals not exceeding 35 or 25 flight cycles, depending on the severity of the condition. This directive becomes effective from 8 July 2004, and its application is geographically within the Commonwealth of Australia.
Key Provisions
The main sections of this Airworthiness Directive (AD) focus on the applicability, requirement, and compliance for Learjet 60 Series aeroplanes equipped with certain Aircraft Braking Systems (ABS) brake assemblies. The AD applies to Model 60 aircraft that have ABS brake assemblies with part number 5003096-7 (Applicability). The requirement section mandates specific actions to address abnormal brake wear conditions. Firstly, it involves measuring the brake wear dimension between the housing sub-assembly and the pressure plate adjacent to the top pistons of the brake assembly (Requirement 1a). Depending on the measurement, subsequent actions include repeating the measurement, conducting a visual inspection for abnormal wear, or replacing the brake components if necessary (Requirement 1b-d). Additionally, used ABS brake assemblies must be inspected and any corrective actions performed before installation (Requirement 2).
The AD imposes several obligations on the parties and entities it governs. Aircraft operators and maintainers must ensure that the specified measurements are taken and the appropriate actions are performed within the stipulated timeframes. For example, if brakes have accumulated more than 100 cycles since new, inspections must occur within 10 flight hours after the effective date of this AD (Compliance 1). Further, used ABS brake assemblies must be inspected and any necessary corrective actions taken before installation (Compliance 2). Failure to comply with these requirements may result in unsafe conditions that could compromise the aircraft's airworthiness.
Breaching the provisions of this AD can result in serious consequences. Although the AD itself does not explicitly state penalties, non-compliance with airworthiness directives in Australia can lead to enforcement actions by the Civil Aviation Safety Authority (CASA). These actions may include fines, suspension or revocation of an aircraft's certificate of airworthiness, and potential criminal charges if the non-compliance leads to an accident or serious incident. The maximum penalties for such breaches can vary, but they may include substantial financial penalties and imprisonment, depending on the severity and impact of the non-compliance.