Date of Occurrence: 23 December 2024
Aircraft: Swiss International Airlines Bombardier CS300 (Airbus A220-300)
Registration: HB-JCD
Flight: LX1885 from Bucharest Otopeni (Romania) to Zurich (Switzerland)
Occupants: 74 passengers, 5 crew
Event Classification: Accident
Location: Approximately 20nm ENE of Graz, Austria
Engine Type: Pratt & Whitney PW1524G
Investigation Status: Preliminary report released by Austrian SUB; investigation transferred to Swiss STSB as of 7 May 2025
Executive Summary
On 23 December 2024, Swiss International Airlines flight LX1885 operating a Bombardier CS300 (Airbus A220-300), registration HB-JCD, experienced an uncontained engine failure while cruising at FL400 over Austria. The event was marked by multiple cockpit EICAS alerts, cabin smoke, and ultimately, the shutdown of the left engine. The crew declared a MAYDAY and diverted to Graz Airport (LOWG), executing an emergency landing and full-scale evacuation.
Tragically, one cabin crew member sustained critical injuries and died seven days later. Multiple other occupants required medical attention. Initial investigation findings confirmed the failure of the left engine’s main shaft and the presence of oil debris. The protective breathing equipment (PBE) worn by the affected crew member has become a focal point of inquiry, alongside procedural handling of contaminated evidence. The incident has raised complex technical, regulatory, and procedural questions across several jurisdictions.
Flight Summary and Operational Narrative
Flight LX1885 departed Bucharest Henri Coandă International Airport bound for Zurich, cruising uneventfully at FL400. At approximately 16:32 UTC, shortly after entering Austrian airspace and in radio contact with WIEN RADAR, the flight crew received an EICAS advisory indicating:
L ENGINE FAULT 79 L ENGINE FAULT – OIL DEBRIS ABOVE LIMIT
Seconds later, a master caution alert for ENG VIBRATION was triggered. A loud bang was reported in the cabin, coinciding with noticeable abnormal engine operation. At 16:34 UTC, smoke became visible in the cockpit, prompting the pilots to don oxygen masks and prepare for emergency procedures.
At 16:34:17, the aircraft generated an EICAS master warning: LAV SMOKE, followed by a repeated aural “smoke” alert. This was immediately followed by:
L ENG OIL PRESS warning Further evidence of engine performance degradation
At 16:34:51, the commander (CM1) issued a MAYDAY call, citing smoke on board, and commenced a descent.
By 16:37:28, the flight crew shut down the left-hand PW1524G engine in accordance with abnormal checklist procedures. The situation deteriorated rapidly, prompting preparation for an emergency landing.
The aircraft was vectored for an ILS approach to runway 34C at Graz, making initial contact with GRAZ RADAR at 16:41:21. Clearance was granted at 16:47:39 and the aircraft landed safely at 16:53:10, coming to a complete stop on the runway.
A total of four emergency exits were used for evacuation. Fire and rescue personnel assisted at the scene.
Post-Landing Consequences
A rescue helicopter was dispatched to the runway where one flight attendant was found to be in critical condition and under resuscitation. The crew member was airlifted to hospital, where he later succumbed to hypoxic brain injury on 30 December 2024.
In total, 17 passengers and crew were treated for smoke inhalation or related medical issues. Both pilots and two additional cabin crew members were also hospitalised.
Swiss International Airlines arranged for a replacement flight (HB-JCG), which transported the remaining passengers to Zurich with a delay of approximately 12.5 hours.
Preliminary Engineering and Technical Findings
According to the Austrian Federal Safety Investigation Authority’s preliminary report (SUB), data from the aircraft’s Flight Data Recorder (FDR), Cockpit Voice Recorder (CVR), and Aircraft Health Monitoring System (AHMS) revealed:
A left engine oil system fault was the first recorded irregularity This was followed by metal debris detection in the oil system Subsequent abnormal vibration and performance degradation warnings confirmed the engine’s deteriorating condition
Initial forensic inspection of the left engine confirmed:
A fractured main shaft, resulting in internal damage Indications of an uncontained engine failure The engine seized in-flight, contributing to oil leakage and smoke Engine replacement was initiated following arrival in Graz
Cabin Crew Fatality and Protective Breathing Equipment (PBE) Concerns
The deceased flight attendant was confirmed to have been wearing a PBE, designed to provide filtered oxygen in smoke conditions. Autopsy findings released by the Austrian State Attorney’s Office on 5 January 2025 revealed:
Severe hypoxic brain damage and oedema Evidence of enlarged cardiac anatomy and septic bronchitis It remains undetermined whether these pre-existing conditions exacerbated the fatal outcome
Importantly, the PBE unit used by the crew member was from a batch flagged in 2023 as potentially defective, and Swiss International had begun a phased recall and replacement program. The unit in question had not yet been exchanged.
The functionality of the PBE, as well as maintenance tracking, has become a key investigative avenue. A joint inquiry by the Swiss STSB and Austrian Prosecutors is underway to determine whether the device operated as intended.
Chain of Custody and Evidence Handling Concerns
On 10 January 2025, reports surfaced via The Aviation Herald suggesting procedural anomalies in how the PBE units were collected and stored following the accident:
A SUB investigation leader removed the PBEs from the aircraft without documented chain-of-custody protocol The equipment was reportedly left unattended in a vehicle for a period of time before being relocated Discrepancies between photographic evidence from passengers and physical PBE condition were noted during police examination
The Austrian Ministry for Mobility, Innovation and Technology later confirmed an investigation was opened on 23 December, but international authorities were only formally notified a week later.
In February 2025, the Austrian Prosecution Office opened a criminal investigation into several SUB officials over alleged procedural violations during this and another unrelated Austrian Airlines event. A house search of SUB offices was conducted.
Procedural Timeline of Key Events
Time (UTC)
Event
16:30:19
First contact with WIEN RADAR
16:32:12
EICAS advisory: L ENGINE FAULT, oil debris above limit
16:33:46
ENG VIBRATION caution triggered, loud bang reported
16:34:12
Smoke detected, pilots don oxygen masks
16:34:17
LAV SMOKE master warning; aural “smoke” alert
16:34:51
MAYDAY declared to ATC
16:37:28
Left engine shutdown
16:41:21
Contact with GRAZ RADAR initiated
16:47:39
ILS approach clearance issued
16:53:10
Landing on runway 34C
16:55:18
Emergency evacuation commenced via four exits
Investigation Status
On 7 May 2025, the Swiss Safety Investigation Board (STSB) assumed control of the investigation at the request of Austrian authorities, citing the operator’s national registration and manufacturer involvement.
The final report is pending, and areas of focus include:
Root cause of the engine failure Functionality and certification compliance of PBE equipment Medical implications and potential underlying health risks Procedural integrity of the initial evidence collection ATC coordination and emergency handling efficacy
Conclusion
The accident involving Swiss International’s Bombardier CS300 on 23 December 2024 represents a rare and complex case of in-flight uncontained engine failure coupled with significant cabin smoke and a fatal crew injury. While the aircraft landed safely and most passengers were unharmed, the event exposed vulnerabilities in both equipment readiness and investigative procedure transparency.
The incident has spurred cross-border cooperation between Swiss and Austrian authorities and raised critical safety oversight questions surrounding engine performance monitoring, smoke protection gear, and post-event investigation practices.
Final conclusions will be issued in due course by the Swiss STSB following full forensic, medical, and procedural analysis.
Disclaimer
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