An engine cowling on a United Airlines’ Flight 1175 blew off over the Pacific Ocean when it was flying from San Francisco to Hawaii, US.

The incident came to light after the passengers heard a loud bang when the flight was still around 35min away from landing in Honolulu.

Images and videos captured through the aircraft windows revealed that the exposed engine was vibrating in mid-air after the engine cowling had ripped off.

Passengers seating on the right side saw pieces of flying metal through their windows, reported

“Our pilots followed all necessary protocols to safely land the aircraft.”

A distress signal was immediately transmitted by the pilots before making an emergency landing.

The flight, however, safely landed with a fully exposed engine.

United Airlines was quoted by theguardian.comas saying: “United Flight 1175 travelling to Honolulu from San Francisco landed safely after the pilots called for an emergency landing because of an issue with the #2 engine.

“Our pilots followed all necessary protocols to safely land the aircraft.

United further added that it is fully cooperating with the National Transportation Safety Board (NTSB) and the US Federal Aviation Administration (FAA) regarding their investigations.

In 2016, an American Airlines aircraft experienced the same situation of the United Airlines Flight 1175, when it was flying from Phoenix, Arizona, to San Francisco, California.

The pilots had to turn back after the cowling fell off mid-air.