AD/F100/10 - Engine Mount Shear Shelf Web

Overview

The Civil Aviation Regulations 1998 (Cth) were enacted to ensure the safety and efficiency of civil aviation within Australia, with the overarching aim of protecting the public from the risks associated with air travel. One specific legislative instrument under these regulations is AD/F100/10, which addresses the issue of potential interference between the fixed cowl mid and aft hooks and the engine mount shear shelf web in Fokker F100 (F28 Mk 100) Series Aeroplanes. This interference has been identified as a significant risk, potentially leading to cracks, increased vibration, and noise, which could compromise the aircraft's structural integrity and safety. The policy objective of this directive is to mandate regular inspections and necessary repairs to mitigate these risks, ensuring that affected aircraft meet the required safety standards before accumulating a certain number of flight hours or continuing operation if cracks are discovered during inspection. This directive aims to maintain the airworthiness of the specified Fokker F100 aircraft, safeguarding both the aircraft and those onboard.

Scope and Application

The Civil Aviation Regulations 1998, under Part 39 - 105, specifically address the airworthiness of Fokker F100 (F28 Mk 100) series aeroplanes through Airworthiness Directive AD/F100/10, which focuses on the engine mount shear shelf web. This legislation applies to a defined subset of Fokker F28 Mk.0100 aircraft, specifically those with serial numbers ranging from 11244 through 11308, 11310, 11312 through 11314, 11316, 11321, 11328, and 11329. The directive mandates inspections and potential repairs to the engine mount shear shelf webs around specific areas to prevent structural integrity issues caused by interference between the fixed cowl mid and aft hooks. Compliance with this directive requires inspections to be carried out before the aircraft accumulates 12,000 flight hours since new, or immediately if cracks are discovered during inspections. The directive became effective on 22 April 1999, ensuring that the specified aircraft are maintained to the required safety standards.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39, Section 105, issue Airworthiness Directives (AD) for certain aircraft, including Fokker F100 (F28 Mk 100) series aeroplanes. This directive, AD/F100/10, pertains to the engine mount shear shelf webs around the fixed cowl aft hook centreline and the fixed cowl mid hook centreline. The directive applies to F.28 Mk.0100 aircraft with specific serial numbers, which are 11244 through 11308, 11310, 11312 through 11314, 11316, 11321, 11328 and 11329 (Section 105). The directive mandates that the engine mount shear shelf webs be inspected for cracks and damage and reinforced accordingly. It specifies that the reinforcement should be done in accordance with Accomplishment Instructions Part 1 or Part 2 of Fokker Service Bulletin (SB) F100-71-012 dated 7 February 1992 (Section 105). Furthermore, if any cracks are detected during the inspection, they must be repaired in line with the Fokker F.28 Mk.0100 Structural Repair Manual (SRM) (Section 105). The Civil Aviation Regulations 1998 impose specific obligations on the parties governed by this directive. The primary obligation is for the relevant aircraft to be inspected and repaired if necessary. Specifically, the engine mount shear shelf webs must be inspected before the aircraft accumulates 12,000 flight hours since it was new (Section 105). If any cracks are detected during this inspection, the repairs must be carried out before any further flight (Section 105). This ensures that the aircraft remains airworthy and safe to fly. Failure to comply with this Airworthiness Directive can result in significant consequences. While the specific penalties are not detailed in the directive, non-compliance with civil aviation regulations can typically result in fines, suspension or revocation of the aircraft's airworthiness certificate, or other enforcement actions. These actions are taken to ensure the safety and integrity of civil aviation operations. It is important to note that these consequences can be severe, given the critical nature of airworthiness directives in maintaining the safety of aircraft and those on board.