Overview
• Operator: Air Libya
• Aircraft Model: Avro RJ-100
• Registration: 5A-FLF
• Flight Number: 7I-155
• Route: Sofia (Bulgaria) → Alexandria (Egypt)
• Date: 3 February 2025
• Occupants: Passengers and crew unspecified
• Nature of Incident: Cabin pressurization problem
• Investigation: Ongoing
Incident Summary
Air Libya flight 7I-155, operated by an Avro RJ-100 (5A-FLF), was climbing out of Sofia when the crew requested to stop the climb at FL160, reporting a high cabin altitude issue. The crew requested an immediate return to Sofia as a precautionary measure.
Air Traffic Control (ATC) cleared the aircraft to descend to FL120 before positioning for an approach to Sofia’s runway 27. The aircraft landed safely approximately 25 minutes after departure.
Records indicate that this aircraft had flown to Sofia on 19 July 2024 and had remained grounded for several months before this flight.
The aircraft remained on the ground in Sofia for about 23 additional hours before departing for Benghazi (Libya) via Alexandria (Egypt) on 4 February 2025.
Sequence of Events
Climb Phase & Pressurization Alert
• During the initial climb, the crew detected abnormal cabin altitude readings, indicating a potential pressurization system failure.
• The climb was halted at FL160, and the crew requested an immediate return to Sofia.
Diversion & Landing
• ATC cleared the aircraft to descend to FL120, assisting in cabin altitude stabilization.
• The aircraft positioned for a return to Sofia, executing a safe landing on runway 27 about 25 minutes after departure.
Post-Landing & Aircraft Status
• The aircraft remained on the ground in Sofia for 23 hours while technical inspections were conducted.
• The aircraft subsequently departed for Benghazi via Alexandria on 4 February 2025.
Potential Causes & Technical Analysis
The exact cause of the pressurization issue remains under investigation, but potential factors include:
1. Cabin Pressure Controller Malfunction
• Faulty cabin altitude sensors or pressure controllers may have triggered a false alert or failed to regulate cabin pressure effectively.
2. Outflow Valve or Cabin Air Leak
• Malfunctioning outflow valves may have failed to regulate internal cabin pressure, leading to excessive altitude fluctuations.
• Structural cabin leaks, particularly after a long period of inactivity, could contribute to pressurization anomalies.
3. Air Conditioning and Bleed Air System Failure
• The pressurization system relies on engine bleed air to regulate cabin pressure.
• Bleed air valve malfunctions or pneumatic leaks could have compromised airflow into the cabin.
4. Aircraft Inactivity-Related Issues
• The aircraft had remained grounded for months, which could have led to stagnation-related mechanical failures in the pressurization system.
Investigation & Aircraft Status
• Air Libya’s maintenance team conducted an assessment in Sofia before the aircraft was cleared to resume operations.
• Given the long period of inactivity before the flight, full pressurization system checks should be conducted to ensure reliability.
• Authorities in Bulgaria, Libya, and Egypt may assess whether additional safety protocols for long-inactive aircraft should be implemented.
Safety Considerations & Best Practices
• Pressurization system checks should be thoroughly conducted before reinstating long-grounded aircraft into service.
• Cabin altitude alerts must be taken seriously, as they can lead to hypoxia if not addressed promptly.
• Crew decisions to return immediately align with best safety practices, ensuring no further risks were introduced into flight operations.
• Regulators may introduce stricter pre-flight certification checks for aircraft that have been inactive for extended periods.
Disclaimer
This report is based on available information as of 4 February 2025. While every effort has been made to ensure accuracy, the completeness of the details cannot be guaranteed. If you are the rightful owner of any referenced materials and wish them removed, please email takedown@cockpitking.com.
