AD/CESSNA 525/1 - Main Landing Gear Trunnion Bearings

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, was enacted to establish safety standards and procedures for civil aviation operations within Australia. This regulatory framework is overseen by the Civil Aviation Safety Authority (CASA) and aims to ensure the safety of aircraft and personnel involved in aviation activities. One of the key legislative instruments within this framework is the Airworthiness Directive (AD) concerning Cessna 525 Series Aeroplanes, which was introduced to address specific safety issues identified with the main landing gear trunnion bearings of these aircraft models. The AD, designated AD/CESSNA 525/1, was issued following an incident where a main landing gear collapse occurred due to a failure in the trunnion bearings, which was attributed to the loss of dry film lubricant. The policy objective of this directive is to mitigate such risks by mandating specific inspection and modification procedures to ensure the continued airworthiness of the affected aircraft.

Scope and Application

The Civil Aviation Regulations 1998, specifically PART 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives concerning Cessna 525 Series Aeroplanes, applies to aircraft of the model 525 with serial numbers ranging from 525-0001 to 525-0153. This legislation mandates that these aircraft must undergo an inspection and subsequent modification of the main landing gear trunnion bearings to prevent failures arising from the loss of dry film lubricant. The directive is applicable across the Commonwealth of Australia, overseen by the Civil Aviation Safety Authority (CASA). Compliance with this directive involves inspecting the main landing gear trunnion pins in accordance with Cessna Service Letter 525-32-11 and modifying them according to Cessna Service Bulletin 525-32-08 Rev 1. The directive references FAA AD 97-01-02 for additional context. Inspections must occur within 25 hours of time in service after the directive's effective date of 19 February 1997 and subsequently at intervals not exceeding 25 hours time in service until the modifications are completed. Modifications must be undertaken within 75 hours of time in service after 19 February 1997, unless already carried out as part of the inspection process. This directive does not specify any exclusions or exemptions, applying uniformly to the identified model and serial number range of Cessna 525 Series Aeroplanes within its jurisdictional scope.

Key Provisions

The Civil Aviation Regulations 1998 (Part 39 - 105) includes an Airworthiness Directive (AD/CESSNA 525/1) concerning the Cessna 525 Series Aeroplanes, specifically addressing the main landing gear trunnion bearings. This directive applies to Model 525 aircraft with serial numbers ranging from 525-0001 to 525-0153. The main requirement of this directive is to inspect the main landing gear trunnion pins in accordance with Cessna Service Letter (SLA) 525-32-11 and to modify them according to Cessna Service Bulletin (SB) 525-32-08 Rev 1. The directive references the Federal Aviation Administration (FAA) AD 97-01-02 for additional context. In terms of compliance, operators must inspect the specified main landing gear trunnion pins within 25 hours of time in service after the directive's effective date of 19 February 1997, and thereafter at intervals not exceeding 25 hours of time in service until the modifications are made. If the inspection has already been performed as a result of the requirement, the inspection step is not necessary. Modifications must be completed within 75 hours of time in service after 19 February 1997, unless they have already been accomplished through the inspection process. Failure to comply with the AD/CESSNA 525/1 may result in serious safety implications, as the directive was issued following a main landing gear collapse during landing roll-out due to trunnion bearing failure. This failure was attributed to the loss of dry film lubricant on the main landing gear trunnion bearings. The legislation does not explicitly detail specific penalties or legal consequences for non-compliance, but the implications of failing to adhere to airworthiness directives can include severe civil or criminal penalties, as well as operational restrictions or grounding of the aircraft until compliance is achieved.