An AirAsia X flight to Malaysia from Perth, Australia, was forced to turn back Sunday after the twin-aisle Airbus A330-300 aircraft began shaking due to what the airline called a "technical issue." A spokesman for the Perth Airport said, "The pilot identified a technical issue with the engine. The plane turned around and safely landed back at Perth Airport." We were asleep and heard a loud bang around the 1-hour-and-15-minute mark," passenger Damien Stevens told CNN. "It shook for the whole ride back, close on two hours." While it's not yet clear what caused the issue with the jet's Rolls-Royce engines, any imbalance inside a rapidly-spinning jet engine can cause violent vibrations that are felt throughout the aircraft. Twin-engine aircraft like the A330 are designed to fly and land safely with only one engine operating. "It was really shaky, very scary," Stevens said. Stevens and friend Mitch Jamieson were on their wa