What happened
On March 20, 2018, an Embraer ERJ190-100IGW, registered as LV-CHR, was operating a scheduled commercial flight from Buenos Aires (Ezeiza) to Iguazú. While cruising at FL370, the flight crew noticed smoke entering the cockpit through the front panel ventilation. This was accompanied by a recirculation smoke alarm on the engine indicating and crew alerting system.
In response to the emergency, the flight crew donned oxygen masks and deactivated the air recirculation system. The crew declared an emergency with Resistencia Center and diverted the aircraft to Posadas. During the descent, cabin crew reported a burning plastic odor between rows 12 and 14. All 73 passengers and 6 crew members evacuated the aircraft via their own means; there were no injuries and no fatalities reported. The aircraft sustained no damage.
The investigation
The investigation focused on the ventilation system and the crew's emergency response. Investigators examined the two air recirculation fans, though no burnt debris or residue was found. During testing, the crew activated the engines and pressurized the cabin to observe the system. While a slight deficiency was noted in the left fan, no smoke or odor was produced during the initial test.
Following the replacement of the left fan, subsequent tests confirmed the recirculation system was functioning according to manufacturer specifications, and the smoke alarm did not trigger.
Findings
- The smoke and burning odor were transient in nature.
- The incident was caused by a malfunction of the left air recirculation fan.
- The most likely failure mechanism was an imbalance in the fan shaft, which caused the plastic blades to contact the internal structure, generating smoke and odor through friction.