Qantas flight QF7 from Sydney to Dallas has returned to Sydney due to a noise issue inside the cabin.
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, a Qantas spokesman said.
Cabin pressure was always maintained and the aircraft landed safely and without incident.
Engineers are inspecting the aircraft and passengers are waiting in the terminal, the spokesman said.
Sydney to Dallas is the second-longest flight on the Qantas network, so a significant amount of fuel needed dumping.
However, the airline's spokesman denied it was to the value of $100,000 as reported elsewhere.
Passengers were expecting to be transferred onto another aircraft by 7:30pm tonight, however Qantas said it could not meet crewing requirements, and passengers will now be put on a 12:35pm flight tomorrow.
