What happened
On September 16, 2015, during the climb phase of a flight from Amsterdam (AMS) to Warsaw (WAW), the crew of an Embraer 190 observed a "CREW OXY LO PRESS" alert on the Engine Indication and Crew Alerting System (EICAS). Following established procedures, the crew performed the necessary checklist items and determined that the flight could continue at a lower altitude, specifically FL100, in accordance with the Quick Reference Handbook (QRH). Following the completion of the flight, an Air Safety Report (ASR) was filed.
The investigation
The investigation examined the technical history of the aircraft's oxygen system. Records indicated that similar pressure issues had occurred on the aircraft, specifically on registration SP-LND, on several dates prior to the incident, including September 9, 12, 14, 15, 17, and 18, 2015. Previous maintenance actions included oxygen bottle servicing and the replacement of the captain's mask stowage box and the first officer's mask sweep. The investigation focused on identifying the source of the ongoing leakage within the oxygen system.
Findings
- The investigation established that the leakage was caused by the first officer's oxygen mask.
- After the replacement of the faulty mask, no further signs of leakage were detected, and the issue did not recur.