A giant hole sheared open on the engine casing of a China Eastern Airlines jet during a flight between Sydney, Australia, and Shanghai, China, Sunday evening, causing a mid-air emergency and forcing the plane back to Sydney.

Terrified passengers said they heard a loud noise and "burning" smell on the Airbus 330, according to The Guardian.

Social media pictures show the massive hole in the air intake cowl encasing the Rolls-Royce Trent 700 engine.

"The moment that we took off, the wing to my left started making a massive amount of noise and cleared all the seats," Nine Network reported a passenger said.

"All of a sudden … it kind of smelled like burning," another passenger told Network Seven.

Flight MU736 safely returned to Sydney Sunday evening. No one was injured, and an investigation is underway, according to the China Eastern Air.