Terror accused targeted Etihad flight: AFP

Police have revealed how close an alleged Sydney terror plot to bomb a plane came to fruition.

Khaled Mahmoud Khayat, 49, is one of the men charged over the conspiracy to bring down the aircraft.

It's alleged he tried to have his unsuspecting brother take a bomb on an Etihad flight from Sydney to Abu Dhabi on July 15.

The pieces for the improvised explosive device were allegedly shipped from Turkey to Australia.

Khayat's unamed brother was unaware the military-grade explosive was hidden in a meat grinder and stashed in his luggage but it never made it through security, police say.

They allege a second attack was planned after the first plot failed. It involved an attempt to build an improvised chemical dispersion device to fill a plane with hydrogen sulfide, a colourless toxic gas.

Khayat, of Lakemba, and Mahmoud Khayat, 32, of Punchbowl, had their matter mentioned in Parramatta Local Court on Friday, after each was charged with two counts of preparing for or planning a terrorist act on Thursday night.

The men, who were refused bail ahead of another court mention on November 14, face a maximum penalty of life imprisonment.

A third man remains behind bars under special anti-terror laws. He can be detained until the weekend.