Overview
• Operator 1: Eurowings
• Aircraft 1: Airbus A319-100
• Registration: D-AGWD
• Flight Number: EW-7520
• Route: Hamburg (HAM) → Barcelona (BCN)
• Operator 2: Emirates
• Aircraft 2: Boeing 777-200
• Registration: A6-EWE
• Flight Number: EK-256
• Route: Mexico City (MEX) → Barcelona (BCN)
• Date: 8 January 2024
• Location: Near Barcelona, Spain
• Casualties: None
• Minimum Separation: 200 feet vertical, 0.6 nautical miles horizontal
• Investigation: Led by Spain’s CIAIAC
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Incident Summary
A loss of separation occurred between Eurowings flight EW-7520 (A319) and Emirates flight EK-256 (B772) during approach to Barcelona El Prat Airport (BCN).
Both aircraft were on approach to runway 24R, with EW-7520 under the control of sector T1W, and EK-256 managed by sector T4W.
Due to incorrect sequencing and inadequate coordination between air traffic control sectors, the two aircraft closed to within 200 feet vertical and 0.6 nautical miles horizontal—triggering TCAS resolution advisories (RA) for both flight crews.
The conflict was ultimately resolved by TCAS before either aircraft reached unsafe proximity.
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Sequence of Events
1. Approach Planning & Sequence Change
• EW-7520 was originally assigned as arrival sequence 7, and EK-256 was sequence 8.
• The T1W sector controller (PC T1W) unilaterally swapped their sequence positions, putting the heavier B777 ahead of the A319.
• This was done without informing the final approach controller (F24W), leading to a misalignment of approach speeds, headings, and altitudes.
2. Poor Coordination Between Controllers
• The T1W controller verbally coordinated the change with T4W, but without using proper procedures.
• T4W misinterpreted the request, issuing a vector to another aircraft (TAP1032) instead of EK-256.
• EW-7520 continued descending through FL80, and EK-256 was cleared to descend through FL103 without speed adjustments, further reducing separation.
3. ATC Fails to Resolve Conflict
• Final approach sector F24W received both aircraft in a compromised position.
• The controller instructed EW-7520 to descend to 5000 feet, even though EK-256 was already at 5900 feet descending to 4000 feet, exacerbating the issue.
• The short distance between aircraft combined with insufficient speed control led to an unsafe situation.
4. TCAS Activates & Conflict Resolved
• The safety alert system (STCA) activated as the aircraft came within 200 feet vertical and 0.6 nm horizontal separation.
• TCAS resolution advisories (RA) were issued to both aircraft, overriding ATC instructions.
• EK-256 initiated an immediate descent per TCAS RA, while EW-7520 adjusted altitude to resolve the conflict.
• ATC, still unaware of the severity of the situation, issued confusing and ineffective instructions, including:
• Mixing up the Eurowings and Emirates callsigns.
• Providing unnecessary course changes while TCAS was already resolving the situation.
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Investigation Findings & Initial Analysis
1. Incorrect Approach Sequencing
• The decision to swap the arrival order of EK-256 and EW-7520 was unjustified and poorly executed.
• The heavier Emirates B777 required more spacing behind it, but controllers failed to adjust speeds accordingly.
• The incorrect sequencing was not communicated to the final approach controller (F24W), limiting their ability to manage spacing.
2. ATC Mismanagement & Poor Coordination
• The T1W and T4W sectors failed to coordinate effectively, leading to:
• Incorrect vectoring of another aircraft (TAP1032) instead of EK-256.
• Lack of speed adjustments, allowing the aircraft to close distance too quickly.
• Unawareness of the flight levels of both aircraft, resulting in an incorrect altitude clearance.
3. Controller Fatigue & Distraction
• The F24W final approach controller was reportedly fatigued due to personal circumstances, affecting their performance.
• ATC ignored multiple separation warnings, likely influenced by frequent false alarms in the system.
4. ATC Issued Confusing & Contradictory Instructions
• When ATC realized the loss of separation, their response was ineffective:
• Instructions were delayed, unclear, and conflicted with TCAS RA commands.
• Controllers issued course changes mid-RA, which contradicted ICAO procedures.
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Probable Cause & Contributing Factors
Primary Cause: Inadequate ATC Approach Planning & Execution
• Incorrect sequencing of aircraft without proper coordination.
• Failure to manage approach speeds, headings, and altitudes.
• Final approach controllers were unaware of the separation conflict until TCAS activated.
Contributing Factors
1. Poor ATC Communication & Misinterpretation
• T1W and T4W sectors did not follow standard coordination procedures.
• Controllers physically left their posts to coordinate verbally, creating confusion.
2. Final Approach Controller Fatigue & Complacency
• The F24W controller was experiencing personal fatigue, affecting situational awareness.
• Repeated false alerts led controllers to ignore real warnings.
3. Lack of Speed & Altitude Adjustments
• No effort was made to slow down EW-7520, resulting in it overtaking EK-256 despite being sequenced behind it.
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Safety Recommendations & Future Prevention
1. Improved Controller Training on Approach Sequencing
• Controllers must follow standard sequence adjustments and communicate changes clearly.
• Mandatory coordination with final approach controllers before modifying arrival sequences.
2. Stronger ATC Conflict Resolution Protocols
• Controllers must actively monitor STCA warnings instead of assuming false alerts.
• Prohibit ATC instructions that interfere with active TCAS RAs.
3. Enhanced Speed & Altitude Management
• Implement real-time speed adjustments for aircraft in changing sequences.
• Ensure speed compliance at waypoints to avoid closing distances too quickly.
4. Fatigue Management & Workload Distribution
• ATC fatigue risk management programs should be reinforced.
• ATC handover procedures should not occur during active conflict resolution.
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Conclusion
A serious loss of separation between Eurowings flight EW-7520 (A319) and Emirates flight EK-256 (B772) occurred during approach to Barcelona, caused by ATC sequencing errors, poor coordination, and lack of speed/altitude management.
The conflict was ultimately resolved by TCAS, preventing a mid-air collision.
The investigation found systemic failures in ATC coordination, controller fatigue, and improper sequencing decisions as primary causes.
Spain’s CIAIAC has issued safety recommendations, focusing on controller training, fatigue management, and conflict resolution protocols to prevent similar incidents.
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Disclaimer
“This report is based on available information as of 10 March 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.”
