A Qantas superjumbo flight en route to Dallas had to turnaround mid-flight due to a defective door seal.
The long range flight was only about an hour into the trip when crew were alerted to a high pitched whistling noise coming from the door.
Qantas said no cabin pressure was lost, but took no chances and timed round back to Sydney.
In doing so, the pilot was forced to dump fuel for a safe landing.
"A door seal was creating a high pitched whistling noise in the cabin, so in the interests of passenger comfort the captain decided to return to Sydney," Qantas said in a statement.
"Cabin pressure was always maintained and the aircraft landed safely and without incident. Engineers are inspecting the aircraft."
The noise from the door was described as ‘unbearable.’
