On 22 December, an Air Canada Boeing 737-8 MAX (registered C-FSNQ) was returning to the air after storage at Marana Pinal, Arizona, United States for a flight to Montreal, Canada. The aircraft carried no passengers, only 3 crew members.
Just after take-off, the crew received a left engine hydraulic low pressure indication. The crew and airline dispatch/engineering controllers initially decided to continue to Montreal but the crew received an indication of a fuel imbalance from the left-hand wing and shut the left hand engine down. The crew declared a PAN PAN emergency and diverted to nearby Tucson for a safe landing. (source: Canada B38M near Tucson on Dec 22nd 2020, hydraulic fault and fuel imbalance, engine shut down in flight – The Aviation Herald)
At first reporting, Aviation24.be wrote about a left-hand engine fault, but the story is more complex. Simon Hradecky from The Aviation Herald explains: “There was no engine fault as such. There was a hydraulic fault in the left engine system, but the engine continued to run, and the crew wanted to continue to destination. But then they received a fuel imbalance and decided to shut the engine down according to QRH (no engine fault, but the suspicion of a fuel leak).”