Overview
On January 2, 2025, a Pakistan International Airlines (PIA) Avions de Transport Regional ATR-42-500, registration AP-BHI, performing flight PK-155 from Karachi to Sui, experienced hydraulic system problems shortly after takeoff from Karachi’s Runway 07R. The crew opted to stop the climb at 5000 feet and safely returned to Karachi, landing on Runway 25L approximately 25 minutes after departure. No injuries or further complications were reported.
Incident Summary
Flight Details
• Aircraft Type: ATR-42-500
• Operator: Pakistan International Airlines (PIA)
• Flight Number: PK-155
• Departure Airport: Karachi Jinnah International Airport (OPKC)
• Destination Airport: Sui Airport (OPSU)
• Passengers and Crew: Details not disclosed, presumed within standard ATR-42-500 capacity.
Sequence of Events
1. The aircraft departed from Runway 07R at Karachi at approximately 11:50 local time.
2. During the initial climb, the crew reported hydraulic system anomalies, leading to system degradation.
3. At 5000 feet, the crew opted to discontinue the climb and declared a return to Karachi, following standard procedures for hydraulic issues.
4. The aircraft landed safely on Runway 25L at 12:15 local time, aided by emergency services positioned as a precaution.
5. The aircraft taxied under its own power to the apron for further inspection.
Technical Analysis
Hydraulic System Overview
The ATR-42 hydraulic system comprises two primary circuits, powered by engine-driven pumps, and an auxiliary hydraulic pump to ensure redundancy. Hydraulic power is critical for landing gear operation, brakes, and flight control surfaces.
Identified Issue
• Preliminary indications suggest degraded hydraulic pressure, potentially linked to:
• Hydraulic fluid leakage: Consistent with repetitive flights showing mechanical wear or maintenance lapses.
• Pump failure or overheating: A known weak point if preventative maintenance is deferred.
• Valve malfunction or contamination: Resulting in reduced hydraulic efficiency.
Aircraft History
This incident occurred less than 24 hours after the same aircraft (AP-BHI) returned to Karachi due to an engine fault during flight PK-503 (Karachi to Gwadar) on January 1, 2025. Persistent technical issues may indicate unresolved mechanical faults or incomplete diagnostics during prior maintenance.
Safety Measures
Crew Actions
The flight crew displayed sound judgment by halting the climb, conducting required checklist procedures, and prioritising passenger safety through a timely return. Their actions align with prescribed emergency protocols for hydraulic failures.
Maintenance Follow-Up
• The aircraft is grounded pending detailed inspection and possible replacement of hydraulic components.
• Comprehensive reviews of recent maintenance logs and engine performance data are underway.
Recommendations
Immediate Actions
1. Hydraulic System Overhaul: Conduct a full inspection and repair of hydraulic circuits, including pumps, valves, and fluid reservoirs.
2. Root Cause Analysis: Investigate any potential link between the hydraulic failure and the previous engine fault incident.
3. Operational Readiness: Reassess the airworthiness of AP-BHI with additional test flights before reintroduction into service.
Long-Term Measures
1. Enhanced Maintenance Protocols: Strengthen periodic checks for hydraulic components in PIA’s ATR-42 fleet.
2. Training Reinforcement: Refresh crew training for early detection and management of recurring technical anomalies.
3. Fleet Modernisation: Evaluate aging aircraft for replacement or upgrades to reduce recurrent technical faults.
Conclusion
The safe return of PK-155 underscores the professionalism of the crew and adherence to emergency protocols. However, the recurrence of technical issues on AP-BHI within 24 hours raises questions about the robustness of maintenance operations. A detailed investigation is essential to identify systemic issues and prevent similar occurrences in the future.
Disclaimer
This report is based on all the evidence and facts available at the time of writing. While every effort has been made to ensure accuracy, we apologise if any details are missed or are not fully accurate. If you are the rightful owner of any associated images and wish them to be removed, please email takedown@cockpitking.com.
