Introduction
On 23 December 2024, a Swiss International Airlines Bombardier C-Series CS-300, registration HB-JCD, operating flight LX-1885 from Bucharest Otopeni (LROP) to Zurich (LSZH), experienced a serious in-flight emergency due to an uncontained left engine (PW1524G) failure and smoke in the cockpit and cabin.
The aircraft was cruising at FL400 when the left-hand engine suffered an oil leak, leading to a catastrophic failure. The flight crew declared a MAYDAY, shut down the affected engine, and executed an emergency diversion to Graz Airport (LOWG).
Upon landing, the aircraft was evacuated on the runway. Tragically, one flight attendant suffered fatal injuries, succumbing to hypoxic brain damage on 30 December 2024. Seventeen passengers and multiple crew members required medical attention, with some being hospitalized.
Flight & Incident Overview
• Aircraft: Bombardier CS-300 (Airbus A220-300)
• Operator: Swiss International Airlines
• Flight Number: LX-1885
• Route: Bucharest Otopeni (LROP) → Zurich (LSZH)
• Date: 23 December 2024
• Occupants: 74 passengers, 5 crew
• Injury Report:
• Fatalities: 1 (flight attendant)
• Injuries: 17 passengers, multiple crew members hospitalized
• Aircraft Damage: Left-hand engine uncontained failure, suspected internal fire, and smoke contamination
• Investigation:
• Austrian Federal Safety Investigation Authority (SUB)
• Swiss Federal Prosecution Office
• Austrian State Attorney’s Office
• Aircraft & Engine Manufacturers Involved
Sequence of Events
Cruise Flight & Initial Emergency
• At 16:30 UTC, the aircraft entered Austrian airspace at FL400, maintaining normal operations.
• At 16:32 UTC, an EICAS warning appeared, indicating L ENGINE FAULT – OIL DEBRIS ABOVE LIMIT.
• At 16:33 UTC, the crew received a master caution for engine vibration. Cabin crew reported hearing a loud bang.
• At 16:34 UTC, a lavatory smoke alarm triggered, shortly followed by an L ENGINE OIL PRESS warning.
• The cockpit and cabin filled with smoke, prompting the crew to don oxygen masks and initiate emergency procedures.
• At 16:34:51 UTC, the captain declared a MAYDAY to ATC, reporting smoke on board and engine trouble.
Emergency Diversion & Engine Shutdown
• The left-hand engine (PW1524G) was shut down at 16:37 UTC, per abnormal procedures.
• The aircraft descended rapidly while the crew attempted cabin coordination via the intercom.
• ATC cleared the aircraft for an emergency approach to Graz (LOWG), and at 16:47 UTC, the crew was cleared for an ILS landing on Runway 34C.
Landing & Evacuation
• The aircraft touched down safely at 16:53 UTC and came to a full stop on the runway.
• At 16:55 UTC, the captain initiated an emergency evacuation due to persistent smoke.
• All passengers and crew evacuated using four emergency exits.
Post-Landing Investigation & Findings
1. Engine Failure & Smoke Source
• Investigation confirmed the left engine suffered an uncontained failure due to an oil leak.
• The engine’s main shaft fractured, leading to internal component failure and smoke contamination in the cabin.
• The engine is undergoing forensic analysis, and a replacement has been ordered.
2. Fatality & Crew Injuries
• A flight attendant suffered severe hypoxic brain damage, succumbing to injuries on 30 December 2024.
• Multiple crew members were hospitalized, with some treated for smoke inhalation.
3. Protective Breathing Equipment (PBE) Issues
• The crew wore protective breathing equipment (PBE), but concerns arose regarding its effectiveness.
• Swiss International Airlines had identified defects in PBEs in 2023, initiating a fleet-wide replacement program, but not all aircraft had been retrofitted.
• The Austrian State Attorney is investigating whether defective PBEs contributed to the fatality.
4. Controversy Over Handling of Evidence
• Reports indicate that the Austrian Federal Safety Investigation Authority (SUB) mishandled crucial evidence.
• On 23 December 2024, an investigator removed PBEs from the aircraft without proper documentation, storing them in a private vehicle before disappearing for a week.
• A police examination later found discrepancies between the PBEs and passenger video evidence.
• The Austrian Prosecution Office launched an investigation into the SUB, its director, and three investigators, also raiding the SUB’s offices in February 2025.
Safety Analysis & Contributing Factors
Primary Cause:
• Uncontained engine failure due to an oil leak, leading to smoke penetration in the cabin and cockpit.
Contributory Factors:
• Protective Breathing Equipment (PBE) concerns – The effectiveness of PBEs used during the incident remains under scrutiny.
• Medical factors – The deceased flight attendant had an enlarged heart and septic bronchitis, potentially influencing survivability.
• Investigation irregularities – Handling of evidence and procedural transparency by Austrian authorities has been questioned.
Safety Recommendations & Preventative Measures
1. Engine Reliability & Monitoring
• Enhanced oil system monitoring for Pratt & Whitney PW1500G-series engines.
• Stricter borescope inspections to detect early wear signs.
2. Protective Breathing Equipment (PBE) Standards
• Full fleet-wide audit of PBEs across Swiss International Airlines.
• Mandatory replacement of all older-generation PBEs.
• Regulatory review of PBE performance in smoke-filled environments.
3. Transparency in Aircraft Accident Investigations
• Stronger oversight of accident investigation bodies to ensure integrity in evidence handling.
• Increased intergovernmental collaboration between Swiss, Austrian, and EU aviation regulators.
Conclusion
The Swiss International Airlines Bombardier CS-300 accident on 23 December 2024 was a result of an uncontained left engine failure caused by an oil leak, leading to smoke ingress into the cockpit and cabin. The flight crew’s rapid response ensured a safe landing and evacuation in Graz, but tragically, one flight attendant lost their life.
Ongoing investigations into protective breathing equipment reliability, engine failure causes, and the mishandling of evidence are expected to yield critical safety recommendations for future operations.
The incident highlights the importance of robust maintenance, crew emergency preparedness, and transparency in aviation safety investigations.
Disclaimer
“This report is based on publicly available information as of 17 March 2025. While every effort has been made to ensure accuracy, we cannot guarantee the completeness of the information provided. If you are the rightful owner of any referenced materials and wish them removed, please email takedown@cockpitking.com.”
