| Project | Explanation |
| Background | The F/A-18A/B Hornet was designed to reach a structural fatigue life of 6,000 hours based on a United States (US) Navy fatigue usage spectrum. However, Royal Australian Air Force (RAAF) fatigue usage is more severe than the US Navy fatigue usage meaning that RAAF Hornets would exhaust their fatigue life far earlier than the manufacturer's specified 6,000 hours. Without some further analysis and structural modification, the RAAF Hornet would not reach its Planned Withdrawal Date. In order to address this issue the RAAF, in collaboration with Canada, initiated the F-18 International Follow-On Structural Test Program to determine the fatigue life of the aircraft and identify modifications to ensure the continued safe operation up to 6,000 flying hours. The results of the F-18 International Follow-On Structural Test Program showed that both RAAF and Canadian Forces Hornet fleets required major mid-life structural modifications to reach a structural fatigue life of 6,000 hours. A number of the proposed modifications are being incorporated on the Hornet fleet during the Hornet Upgrade Air 5376 Phase 3.1 Project providing continued airworthiness up to 78% of the intended structural fatigue life. Phase 3.2 incorporates further structural modifications as described in the Project Description above providing sufficient fatigue life for the Hornet fleet to reach its Planned Withdrawal Date. L-3 Communications MAS (Canada) Inc. based in Mirabel, Canada was the contractor selected for design and prototyping of the Hornet Upgrade Phase 3.2 modifications. L-3 Communications MAS (Canada) Inc. was selected due to its experience in designing, prototyping and installing almost identical modifications on the Canadian Hornet fleet. Through innovative application of airframe structural testing and analysis (by Defence Science & Technology Organisation [DSTO]) of centre barrels obtained from early Phase 3.2 production aircraft, the number of aircraft requiring the costly centre barrel replacement has been reduced from 49 to 10. In December 2010, Government approved the reduction in the number of centre barrel replacements. Concurrently, Government approved closure of Phase 3.1 and 3.2. Some of the funds are programmed for return to the Defence Capability Plan, and are also identified as an offset to address structural ageing aircraft issues to the Hornet sustainment budget under the Hornet structural assurance consolidation project (HSACP). |
| Uniqueness | This project does not introduce any new capability to the Hornet aircraft fleet. It is a large structural modification program designed to ensure the structural fatigue life of the fleet is sufficient to meet the Planned Withdrawal Date. Therefore, the project does not have approved Initial Materiel Release (IMR), Initial Operational Capability (IOC), Final Materiel Release (FMR) and Final Operational Capability (FOC) dates. |
| Major Challenges | The nature of structural refurbishment of an ageing aircraft is such that unknown conditions may be revealed in the process of disassembly. This may result in more extensive refurbishment work becoming necessary and its unpredictable nature poses a challenge to the production schedule. As a further consequence of the disassembly required during structural refurbishment, additional parts may be required to replace those that are found to be unserviceable. Obtaining these parts in time to maintain the production schedule is a major risk confronting the project. |
| Other Current Projects/Sub-Projects | AIR 5376 Phase 3.1 F/A-18 Hornet Upgrade - This is a complimentary structural modification project that provides continued airworthiness from 64% to 78% of the intended structural fatigue life. |