On October 10, 2024, an Air Canada Rouge Airbus A319-100, registration C-GBHO, experienced a hydraulic failure shortly after departure from Toronto Pearson International Airport (YYZ). The aircraft was operating flight RV-1534 from Toronto to Saint John, NB with 121 people on board. During the initial climb out of Toronto’s runway 23, the crew received a warning indicating the failure of the green hydraulic system and a subsequent Power Transfer Unit (PTU) fault. The crew declared a PAN PAN emergency and returned safely to Toronto approximately 45 minutes after departure.
Incident Summary
• Aircraft Model: Airbus A319-100
• Registration: C-GBHO
• Flight Number: RV-1534
• Route: Toronto Pearson International Airport (YYZ) to Saint John Airport (YSJ)
• Incident Altitude: Levelled off at 7,000 feet after hydraulic system failure at 3,600 feet
• Date and Time: October 10, 2024
• Duration of Emergency: Approximately 45 minutes from departure to safe landing
During the initial climb, the crew received alerts indicating the failure of the green hydraulic system, one of the three independent hydraulic systems on the Airbus A319. This failure was compounded by a fault in the Power Transfer Unit (PTU), a component that transfers hydraulic power between the green and yellow systems when needed. The crew acted swiftly, leveling off at 7,000 feet, working through emergency checklists, and coordinating with air traffic control for an expedited return to Toronto.
Technical Overview of the Airbus A319 Hydraulic System
The Airbus A319 is equipped with three independent hydraulic systems: green, yellow, and blue. These systems power critical components such as the landing gear, flaps, slats, rudder, and braking systems.
1. Green Hydraulic System
• Primary Components Powered: Landing gear, slats, flaps, rudder, and thrust reversers.
• Sources of Pressure: Engine-driven pumps (usually powered by the left engine) supply the hydraulic pressure needed to operate these systems.
• Failure Impact: A failure of the green system can impact multiple critical flight controls, necessitating the use of backup systems.
2. Power Transfer Unit (PTU)
The PTU is designed to automatically transfer hydraulic power between the green and yellow systems when a pressure differential of more than 500 psi is detected. It operates mechanically, using pressure from one system to drive a pump that transfers hydraulic power to the other.
• Function: Ensures that essential systems remain operational even if one hydraulic system loses pressure.
• Common Issues: PTU faults often arise from sensor malfunctions, pressure anomalies, or hydraulic fluid contamination.
Incident Response and Crew Actions
Upon receiving the hydraulic failure and PTU fault indications, the crew followed established emergency protocols:
1. Leveling Off and Assessing the Situation: The aircraft stopped climbing at 7,000 feet, a safe altitude that allowed the crew to stabilize the aircraft and work through emergency checklists.
2. Checklist Execution: The crew performed the procedures associated with hydraulic system failures, assessing the functionality of backup systems and determining the extent of the failure.
3. Declaring PAN PAN: The crew declared a PAN PAN emergency, signaling an urgent but non-life-threatening situation. This declaration allowed for priority handling by air traffic control and prepared ground services for the aircraft’s return.
4. Safe Return to Toronto: After ensuring the aircraft was in a stable condition, the crew coordinated with air traffic control and executed a safe landing on runway 23 at Toronto Pearson International Airport.
Maintenance Findings and Resolution
The Canadian Transportation Safety Board (TSB) reported that maintenance crews discovered a defective low-level switch for the green hydraulic system. This switch monitors hydraulic fluid levels and activates alerts if the fluid level drops below a certain threshold. The defective switch was replaced, and subsequent serviceability tests confirmed that the hydraulic system was functioning correctly.
Key Maintenance Actions:
1. Switch Replacement: The faulty low-level switch was removed and replaced with a new, fully functional unit.
2. Hydraulic System Testing: Comprehensive tests of the green hydraulic system were conducted to ensure there were no further issues. The PTU and related components were also tested for reliability.
3. Return to Service: After the successful completion of all tests, the aircraft was declared serviceable and returned to operational status.
Understanding the Critical Nature of Hydraulic Failures
Hydraulic systems are essential for modern aircraft, providing the force needed to operate flight controls, landing gear, and braking systems. The failure of one hydraulic system, like the green system on the A319, can significantly impact aircraft handling and safety.
1. Redundancy and Backup Systems:
The Airbus A319’s design includes multiple independent hydraulic systems to ensure continued operation even if one system fails. In this case, the remaining yellow and blue systems would have provided sufficient hydraulic power to control the aircraft and safely return to the airport.
2. Impact of PTU Malfunctions:
The PTU plays a crucial role in maintaining hydraulic power balance. A PTU fault, combined with a hydraulic system failure, complicates the situation by limiting the aircraft’s ability to manage hydraulic power distribution efficiently. However, the Airbus A319 is designed to remain controllable and safe even under such adverse conditions.
Safety Measures and Crew Training
The incident highlights the importance of robust safety systems and comprehensive crew training. Airline pilots undergo rigorous training to handle hydraulic failures and other in-flight emergencies, ensuring they can make quick, informed decisions under pressure.
• Emergency Drills: Pilots practice handling hydraulic system failures in flight simulators, where they learn to manage manual reversion modes and backup systems.
• System Familiarization: Pilots are thoroughly familiar with the aircraft’s hydraulic architecture, allowing them to troubleshoot issues effectively.
Conclusion
The Air Canada Rouge Airbus A319 incident on October 10, 2024, underscores the reliability of modern aircraft design and the effectiveness of crew training in managing complex in-flight emergencies. Despite the failure of the green hydraulic system and a subsequent PTU fault, the crew’s prompt actions ensured the safety of everyone on board. The swift resolution of the issue by maintenance teams further highlights the importance of regular inspections and system checks.
Disclaimer
This analysis is based on information available at the time of writing, including reports from the Canadian TSB and Air Canada Rouge. Further updates may be released as investigations continue. We apologize for any discrepancies or incomplete details.
