A terrifying situation unfolded on an Air Canada flight this month after a pilot became "incapacitated" during a flight out of Toronto Pearson International Airport, however, the crisis was quickly averted after a deadheading captain stepped in and took over. 

The incident involved an Air Canada flight from Toronto to St. John's, Newfoundland operated by an Airbus A220-300, according to the aviation accident and incident website, Aviation Herald. 

On June 7, Air Canada flight AC692 departed from Pearson Airport at 5:58 p.m., which was an hour delay from its original scheduled departure time of 4:50 p.m. The aircraft was carrying 125 passengers and six crew members. 

According to Aviation Herald, the first officer of the aircraft became "incapacitated" 77 minutes after departure, which resulted in a "deadheading captain" assuming the crew member's duties and performing a safe landing 90 minutes later. 

The ATP Flight School says the first officer (also called a co-pilot) is a commercial airline pilot who works in the cockpit with the captain to assist them with the flight. They usually sit in the right seat and are the second in command (SIC), while the captain sits in the left seat and is the pilot in command (PIC). 

It's not clear why the pilot was incapacitated, but emergency medical services met the aircraft at the gate upon its arrival in St. John's at 10:26 p.m. local time. Luckily, no other injuries were reported, and the aircraft landed without further incident.