Several passengers have been kicked off a Qantas flight after the aircraft was reportedly too heavy to fly.

Unhappy travellers flying from Sydney to Perth told Radio 6PR up to 40 passengers were told to disembark from the Boeing 737-800 plane on Monday night.

A Qantas spokeswoman blamed the incident on an “engineering issue” which allegedly affected the plane’s load readings.

“Flight QF569 from Sydney was delayed following a technical issue with the fuel pump which affected the plane’s weight and balance. A number of customers were re-accommodated onto the next available service QF571, which departed shortly after,” she said in a statement.

Travellers were delayed over 45 minutes due to the issue. Photo: AAP

“These passengers on QF571 arrived in Perth within five minutes of their original flight.

“We sincerely thank our customers for their patience and understanding.”

The flight scheduled to land in Perth at 7.40pm but was delayed by almost an hour as a result of its issues, according to passengers onboard.

In April, Qantas was ranked 36th in an international passenger survey, astonishingly making it the best-performing Australian airline in the survey.

The survey, which collected 11,273 responses from eight different countries rated Qantas “OK” with three out of a possible five stars for overall satisfaction.

Meanwhile, its budget carrier, Jetstar, was ranked the worst of all airlines for on-board comfort (4.51 out of 10), check-in process (6.43), boarding (6.13), staff satisfaction (6.64), meals (2.32) and punctuality (6.04).