For the second day in a row, a Disney-themed WestJet plane leaving Calgary had to turn back after smoke was reported in the cockpit.

Flight 662 to Toronto turned back shortly after takeoff on Friday.

"There was an odd smell, and then an alarm went off," said passenger Becky Salmond.

"The plane then began to turn around and the crew announced we would be heading back to Calgary. Everyone was very calm," said Salmond.

"The airport fire trucks arrived when we landed, and seemed to accompany us back to the terminal."

Passenger Becky Salmond took this picture of a fire truck near the plane as she landed back in Calgary Friday morning. (Becky Salmond)

The Boeing 737 landed safely and no injuries have been reported.

On Thursday morning, WestJet Flight 1402 to Phoenix — the same plane — had to return to Calgary with the same issue after taking off.

It made an emergency landing after burning off fuel. Again, there were no injuries.

In a statement released on Friday, WestJet said a maintenance issue caused the air conditioning system to blow smoke into the aircraft, causing the crew to declare an emergency.

The company says maintenance was conducted overnight after Thursday's incident, but additional maintenance inspections will be conducted before the aircraft is allowed to return to service.

Both declarations of emergency were precautionary and did not necessarily mean the plane was ever in danger, the company said.