Flight SK-4483 | Registration: SE-RSK
Date: 9 April 2025 | Location: Trondheim Airport (ENVA), Norway
Flight Details
• Aircraft Type: Embraer ERJ-195LR
• Engines: 2 × General Electric CF34-10E
• Operator: SAS Scandinavian Airlines (operated by CityJet)
• Registration: SE-RSK
• Flight Number: SK-4483
• Callsign: SAS4483
• Route: Trondheim Airport Værnes (ENVA) to Stavanger Sola Airport (ENZV), Norway
• Date of Incident: 9 April 2025
• Total Occupants: Estimated 120 (including crew)
• Weather Conditions: Visual meteorological conditions (VMC) reported
Introduction
On 9 April 2025, a Scandinavian Airlines Embraer ERJ-195 operating flight SK-4483 from Trondheim to Stavanger returned to its departure airport shortly after take-off due to a suspected fuel leak. The aircraft, registered SE-RSK, had departed runway 27 and was climbing through FL170 when the crew received indications of abnormal fuel behaviour. The flight crew took precautionary action, stopped the climb, and returned to Trondheim for a safe landing approximately 30 minutes after departure. No injuries were reported, and the rotation was cancelled pending technical investigation.
Sequence of Events
Shortly after departing Trondheim Airport, the aircraft commenced a normal climb toward cruise altitude. At approximately FL170, the flight crew observed a possible fuel imbalance and/or low quantity warning affecting one of the fuel tanks. This anomaly was supported by fuel flow irregularities or rate of consumption indicators deviating from expected performance.
Recognising the potential severity of an active fuel leak, the crew stopped the climb and initiated a return to base. Standard diversion procedures were followed, including:
• Leveling off and reducing thrust settings to conserve fuel
• Cross-checking engine parameters and fuel system displays
• Communicating with ATC and requesting priority return
The aircraft entered a holding pattern or direct descent vector and returned to land on runway 27 without incident. No emergency evacuation was required, and the aircraft taxied to the stand under its own power.
Crew & Communication
The flight crew followed standard abnormal checklist procedures for suspected fuel leak scenarios. This typically involves:
• Monitoring cross-feed and tank levels
• Comparing fuel quantity indications against fuel flow and time elapsed
• Securing affected engine or fuel pump systems if needed
• Informing ATC and initiating a controlled return
A fuel leak warning may arise from a combination of:
• Rapid decrease in tank quantity
• Fuel imbalance between left and right wing tanks
• Low fuel temperature or pressure
• Fuel vapour or odour detection in the cockpit or cabin
Communication with passengers remained calm and informative, with announcements made explaining the return to Trondheim was precautionary in nature.
Aircraft Systems & Technical Analysis
The Embraer ERJ-195 features a dual-wing tank fuel system, crossfeed capability, and independent monitoring for each engine. A suspected leak can originate from:
• Wing fuel lines
• Tank venting or overpressure
• Fuel pump or valve seals
• Engine pylon or nacelle lines
• Refuelling panel or cap seals
Post-flight inspection would include:
• Draining and pressure-testing the fuel system
• Visual inspection of nacelle and wing undersides
• Evaluation of fuel quantity probes and sensors
• Checking engine cowlings for leak trails or fuel staining
If the leak was external and visible, it would prompt deeper inspection of pipework, seals, and wing root joints. An internal leak could also stem from faulty indicators or sensor mismatches.
The aircraft remained on the ground in Trondheim and the rotation was officially cancelled, indicating further diagnostics or parts replacement were required.
Passenger Experience & Cabin Conditions
There were no reports of odour, smoke, or in-flight discomfort. Cabin conditions remained normal, and passengers were kept informed throughout the return procedure.
Cabin crew would have checked for any visible fuel vapours or unusual smells in the cabin, particularly near wing-mounted exits and rear galleys. No emergency descent or oxygen deployment was required, and the atmosphere remained stable.
The return to Trondheim was described as smooth and uneventful.
Emergency Response & Aftermath
Airport emergency services were placed on standby but did not intervene. Following arrival, engineering teams met the aircraft for immediate inspection. The aircraft was removed from service for safety reasons, and the affected rotation to Stavanger was cancelled.
Passengers were either rebooked on later flights or offered ground transport options depending on their destination and urgency.
Scandinavian Airlines released a short statement confirming the technical issue and praised the crew for their professional handling of the situation.
Investigation Status
The Norwegian Civil Aviation Authority (Luftfartstilsynet) may request a technical summary from SAS maintenance teams. The incident is not classified as a serious occurrence under EASA or ICAO unless confirmed as a substantial fuel system breach.
The maintenance team’s investigation is expected to focus on:
• Detailed examination of fuel line integrity
• Fuel leak detection test results
• Review of the aircraft’s fuel uplift history and recent servicing
• Any deferred maintenance items linked to the fuel system
No airworthiness directive (AD) has been issued for the ERJ-195 type in relation to fuel system defects in recent months, though historical issues with vent valves and coupling seals have occurred on similar models.
Root Cause & Contributing Factors
Probable Root Cause:
Suspected active fuel leak detected by abnormal fuel quantity indications during climb.
Contributing Factors:
• Possible leak at wing or nacelle fittings
• Sensor mismatch or erroneous probe readings
• Recent fuelling operation or service item not properly secured
• Age-related seal degradation or vibration-induced fatigue
The crew’s early intervention prevented potential escalation, including fuel starvation or engine shutdown.
Safety Recommendations & Industry Impact
This incident reinforces several key operational safety points:
• Vigilant fuel system monitoring during all flight phases, especially climb-out
• Quick crew decision-making to prioritise a return in case of potential fuel leaks
• The need for rigorous post-fuelling inspection and coupling integrity checks
• Continued evaluation of probe and sensor reliability on ageing regional jets
SAS may initiate a fleet-wide inspection campaign for similar ERJ-195 aircraft to rule out systemic issues.
Conclusion
The diversion of SAS flight SK-4483 following a suspected fuel leak demonstrates the importance of proactive flight crew response and precise abnormal system handling. While the incident did not escalate into an emergency, the decision to return reflects a strong safety culture and a prioritisation of passenger wellbeing.
Ongoing technical evaluation will determine the exact source of the leak and guide any necessary operational or engineering corrective actions.
Disclaimer
This article is based on publicly available information and reports at the time of writing. While every effort has been made to ensure accuracy, we cannot guarantee the completeness of the information provided.
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