A Sydney man who claimed he was trying to prevent a terrorist attack has been found guilty of plotting to blow up an Etihad plane with a bomb hidden in a meat grinder.

Khaled Khayat, 51, had pleaded not guilty to conspiring - between mid-January and late-July 2017 - to preparing or planning a terrorist act.

But a NSW Supreme Court jury on Wednesday found him guilty of the charge which involved the Etihad bomb plot and another plan to carry out a lethal poisonous gas attack on people in a confined space.

AAP

The jury is still deliberating on the same charge for Khayat's 34-year-old brother Mahmoud.

Prosecutor Lincoln Crowley QC alleged the bomb was in a meat grinder to be put into the luggage of a passenger who was flying out of Sydney on the Etihad flight.

Khaled Khayat in his police interview spoke of walking into the airport with the concealed bomb.

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He said when he saw children at the airport he thought "Don't do it, don't be stupid, don't do it" and removed the bomb from the baggage.

But his barrister, Richard Pontella, told the jury that contrary to what his client told police he never took the bomb to the airport and actually was trying to prevent a terrorist attack.