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 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 45 Series Aeroplanes
AD/LJ45/7 Main Landing Gear Trunnion Shear Pins 11/2003
DM
Applicability: Model 45 aircraft, serial numbers 45-005 through 45-208, 45-210 through 45-222, 45-
224, 45-225, 45-227, and 45-229 through 45-231.
Requirement: 1. Revise the airworthiness limitations (AWL) section of the Instructions for Continued Airworthiness by inserting the instructions for Inspection Reference Numbers (IRN) J3220041, J3220042, and J3220043 (shear pins); as specified on page 2 of Chapter 4-11-00, Revision 32, dated 13 June 2003, of the Learjet 45 Maintenance Manual; into the AWL section. Thereafter, unless FAA approved, no alternative replacement interval may be approved for the shear pins in the trunnion assemblies of the main landing gears.
2. Replace the shear pins, having part number 4532103015-001V1088, 4532103015-003, 4532103025-001V1088, or 4532103026-001V1088, located in the trunnion assemblies of the main landing gears with new, improved shear pins (including re-identifying the trunnion assemblies); in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 45-57-6, dated 9 June 2003.
Note: FAA AD 2003-16-09 Amdt 39-13262 refers.
Compliance: 1. Within 14 days after 3 September 2003.
2. Before the accumulation of 1,800 total landings on the shear pins, or within 100 landings after 3 September 2003, whichever occurs later.
This Airworthiness Directive becomes effective on 3 September 2003.
Learjet 45 Series Aeroplanes
AD/LJ45/7 (continued)
Background: Results of fatigue testing conducted by the manufacturer on the main landing gears of Learjet 45 aircraft indicate that certain shear pins on the trunnion assemblies of the main landing gears do not meet the expected life limit. The results of fatigue testing also indicated that the shear pin bushings in the trunnion fitting housings had migrated outward from the fitting, which further weakened the shear pins and contributed to premature failure. This condition, if not corrected, could result in collapse of a main landing gear, and consequent reduced controllability of the aircraft during takeoff and landing.
David Villiers
Delegate of the Civil Aviation Safety Authority 28 August 2003
The above AD is notified in the Commonwealth of Australia Gazette on 3 September 2003.
Overview
The Airworthiness Directive (AD) issued under the Civil Aviation Act 1988 (Cth) addresses an identified safety issue with the main landing gear trunnion shear pins of Learjet 45 series aeroplanes, specifically for aircraft within certain serial number ranges. The AD was introduced by the Civil Aviation Safety Authority (CASA) to address a potential risk of premature failure of the shear pins, which could lead to a collapse of the main landing gear and consequently, a reduction in the controllability of the aircraft during critical phases of flight such as takeoff and landing. The directive mandates specific actions, including the revision of airworthiness limitations and the replacement of shear pins with improved versions, to be undertaken within specified timeframes to mitigate the identified safety risk.
Scope and Application
The Airworthiness Directive (AD) F2006B11168, issued by the Civil Aviation Safety Authority (CASA) under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998, applies specifically to certain Learjet 45 Series Aeroplanes, namely those with serial numbers ranging from 45-005 through 45-208, 45-210 through 45-222, 45-224, 45-225, 45-227, and 45-229 through 45-231. This AD mandates corrective actions to address identified safety issues related to the main landing gear trunnion shear pins. The directive requires that specific airworthiness limitations be updated in the Instructions for Continued Airworthiness and mandates the replacement of specific shear pins in the main landing gear trunnion assemblies. Compliance with these directives is crucial, with specific timelines provided for actions such as updating documentation and replacing parts, ensuring that these aircraft remain airworthy and safe for operation. The AD is applicable nationally within Australia, and its scope is not restricted by state or territory boundaries. This AD does not specify any exclusions or exemptions, and its requirements must be strictly adhered to by all relevant operators and maintainers of the specified Learjet 45 aircraft.
Key Provisions
The main sections of this Airworthiness Directive (AD) specify the requirements and actions needed to correct a safety issue with the main landing gear trunnion shear pins of the Learjet 45 Series Aeroplanes. Section (a) of the applicability clause identifies the specific Learjet 45 aircraft that are subject to this directive, namely those with serial numbers 45-005 through 45-208, 45-210 through 45-222, 45-224, 45-225, 45-227, and 45-229 through 45-231. Section (b) of the requirement clause mandates that the airworthiness limitations (AWL) section of the Instructions for Continued Airworthiness must include specific inspection reference numbers (IRN) for the shear pins and prohibits the approval of alternative replacement intervals for these pins unless approved by the Federal Aviation Administration (FAA). Section (c) of the requirement clause requires that the shear pins in the trunnion assemblies of the main landing gears be replaced with new, improved ones in accordance with the instructions provided in Bombardier Service Bulletin 45-57-6. The compliance clause, section (d), sets forth the timeframe for these actions, which must be completed within 14 days after 3 September 2003 and before the accumulation of 1,800 total landings on the shear pins, or within 100 landings after 3 September 2003, whichever occurs later.
The obligations imposed on the parties governed by this AD include ensuring that the specified Learjet 45 aircraft undergo the required inspections and replacement of shear pins in their main landing gear trunnion assemblies. Aircraft owners, operators, and maintenance providers must follow the instructions detailed in the Learjet 45 Maintenance Manual and Bombardier Service Bulletin 45-57-6 to ensure that the AWL section of the Instructions for Continued Airworthiness is updated with the correct IRN and that the specified shear pins are replaced with the new, improved ones. Failure to comply with these obligations may result in the aircraft being deemed unairworthy, potentially leading to grounding and operational disruptions.
The AD does not explicitly outline offences or penalties for non-compliance within the text provided; however, failure to comply with an AD issued under the Civil Aviation Act 1988 can lead to significant consequences. Non-compliance may result in the aircraft being declared unairworthy, leading to potential fines, legal action, and operational penalties for the aircraft owner or operator. Furthermore, the AD references FAA AD 2003-16-09 Amdt 39-13262, indicating that the FAA also imposes its own penalties for non-compliance with related directives. These consequences underscore the importance of adhering to the specified requirements to maintain airworthiness and ensure the safety of the aircraft and its occupants.