Regional airport staff and emergency services are undergoing security awareness training following an incident in February, when it's alleged a woman attempted to hijack an Air New Zealand plane.
Staff have a list of key behaviours to look out for in passengers, including people who fidget or are over-protective of bags, and those who are over-friendly or flirtatious.
They are also watching for people who lick their lips, with the advice being that a dry mouth can be due to excess adrenaline.
But the Civil Aviation Authority (CAA) says workers have also been reminded that there can be other explanations for these behaviours.
The training has been developed by the CAA and the Aviation Security Service.
A 33-year old woman, Asha Abdille, faces 15 charges over the incident in February, including stabbing two pilots and a passenger.
It happened on an Eagle Air service, a subsidiary of Air New Zealand, flying from Bleinhem to Christchurch.