Ethiopian Airlines Dash 8-400 Smoke in Cabin

On May 7th, 2024, an Ethiopian Airlines de Havilland Dash 8-400, registration ET-ARN, operating flight ET-154 from Awasa to Addis Ababa, Ethiopia, encountered a serious incident involving smoke in the cabin. The flight, which was carrying passengers on a domestic route, was en route when thick smoke suddenly appeared inside the passenger cabin, causing significant concern among passengers and crew.

Sequence of Events:

Initial Incident:

While cruising towards Addis Ababa, the crew of the Dash 8-400 noticed the sudden appearance of thick smoke within the aircraft cabin. The source of the smoke was not immediately apparent, and there were no indications of fire or alarm triggers in the cockpit. The crew acted quickly to address the situation, ensuring that all safety protocols were adhered to while maintaining communication with air traffic control (ATC) at Addis Ababa Bole International Airport.

Crew Response and Precautionary Measures:

Upon detecting the smoke, the crew followed established emergency procedures to manage the situation and ensure passenger safety. They immediately made an announcement to reassure passengers while simultaneously preparing for a potential emergency landing. Cabin crew members worked swiftly to keep passengers calm and ready for any necessary evacuation. The captain communicated with ATC to request priority landing clearance at Addis Ababa, declaring an emergency due to the smoke in the cabin.

Descent and Landing at Addis Ababa:

ATC at Addis Ababa Bole International Airport granted priority clearance for flight ET-154, and the aircraft began its descent. The crew initiated a rapid but controlled descent to minimize any further escalation of the situation. Despite the thick smoke inside the cabin, the aircraft remained structurally sound, and all systems continued to function normally. The Dash 8-400 landed safely on the designated runway at Addis Ababa without any visible signs of fire or damage to the aircraft.

Post-Landing Actions:

After safely landing, the crew brought the aircraft to a stop on the taxiway, and the passengers were disembarked normally using the boarding stairs. Emergency services were on standby at the airport and closely monitored the situation but did not find any evidence of fire or visible damage to the aircraft. All passengers and crew disembarked safely, and there were no injuries reported among the occupants.

Investigation and Preliminary Findings:

Airline Report and Immediate Actions:

Ethiopian Airlines confirmed that thick smoke had appeared in the cabin during the flight but emphasized that the aircraft had landed safely and there were no injuries or damage. The airline immediately grounded the aircraft pending an investigation to determine the cause of the smoke. Maintenance teams were dispatched to inspect the aircraft and assess any potential faults in the electrical or environmental control systems that might have contributed to the smoke incident.

Ethiopia’s Civil Aviation Authority (CAA) Investigation:

Following the incident, Ethiopia’s Civil Aviation Authority (CAA) launched an official investigation to ascertain the cause of the smoke in the cabin. The investigation team included representatives from the airline, aircraft manufacturer de Havilland, and relevant aviation safety experts. The primary focus of the investigation was to determine whether the smoke resulted from an electrical fault, a malfunction in the aircraft’s air conditioning system, or any other technical failure.

Initial Inspection and Areas of Focus:

The initial inspection by Ethiopian Airlines’ maintenance team focused on several critical areas:

1. Environmental Control System (ECS): The environmental control system, which manages cabin air circulation and pressurization, was thoroughly examined for signs of malfunction, overheating, or contamination. Particular attention was given to components such as air ducts, heat exchangers, and air filters to check for blockages, leaks, or mechanical failure that could have caused smoke to enter the cabin.
2. Electrical Systems: All electrical wiring and connections within the aircraft were inspected for signs of arcing, short circuits, or insulation failure that might have led to smoke generation. Special attention was paid to areas behind the cabin walls, overhead panels, and the avionics bay, where electrical faults could have gone unnoticed during routine checks.
3. Onboard Equipment and Appliances: The aircraft’s galley equipment, such as ovens and coffee makers, and other potential sources of smoke, were examined to rule out malfunctioning or overheating components. Additionally, lavatory systems and other equipment that could generate smoke were inspected to identify any anomalies.
4. Passenger Baggage and Cargo: Investigators also checked passenger baggage and the cargo hold to rule out any flammable materials or hazardous items that might have contributed to the incident.

Ongoing Investigation and Safety Implications:

Continued Focus Areas:

As part of the investigation, the Ethiopian CAA is coordinating with de Havilland, the aircraft manufacturer, to understand any potential design vulnerabilities or previous incidents involving smoke in the cabin on the Dash 8-400 series. This collaboration aims to determine whether the smoke incident on flight ET-154 was an isolated occurrence or part of a broader issue.

Safety Actions and Recommendations:

Pending the outcome of the investigation, Ethiopian Airlines has taken precautionary measures to inspect similar aircraft in its fleet for any indications of issues that could lead to smoke or fire hazards. The airline is reviewing its emergency response protocols to ensure that cabin crews are fully prepared to handle incidents involving smoke in the cabin. Additional training and drills are being conducted to reinforce effective communication and management strategies during such emergencies.

Implications for the Aviation Industry:

This incident serves as a reminder of the importance of vigilant monitoring of onboard systems and the need for rigorous maintenance and inspection protocols to prevent smoke or fire hazards. It also underscores the critical role of effective crew coordination and communication during in-flight emergencies to ensure passenger safety.

Next Steps in the Investigation:

The Ethiopian CAA is expected to release a preliminary report summarizing initial findings from the ongoing investigation in the coming weeks. The report will provide an overview of the potential causes of the smoke and any immediate safety recommendations. A final report, including comprehensive analysis and any long-term safety recommendations, will follow once the investigation is concluded.