According to VIC Law for the charge of Unlawfully taking control of an aircraft,

Crimes Act 1958 - SECT 80

Unlawfully taking control of an aircraft

80. Unlawfully taking control of an aircraft

(1) A person who without lawful excuse takes or exercises control, whether direct or through another person, of an aircraft while another person not being an accomplice to the first-mentioned person is on board the aircraft shall be guilty of an indictable offence and shall be liable to level 4 imprisonment (15 years maximum).

(2) A person who without lawful excuse, by force or violence or threat of force or violence or by any trick of false pretence, takes or exercises control, whether direct or through another person, of an aircraft while another person not being an accomplice of the first-mentioned person is on board the aircraft shall be guilty of an indictable offence and shall be liable to level 3 imprisonment (20 years maximum).

According to VIC Law for the charge of Unlawfully taking control of an aircraft,
15 - 20 years depending on subsection charged under

1. That the accused took or exercised control of an aircraft.
2. The accused took or exercised control either directly or through another person.
3. That another person other than an accomplice of the accused was onboard the aircraft.
4. The accused had no lawful excuse to take control of the aircraft
5. The prosecution may prove an aggravated form of the offence by proving that control was taken or exercised
by either:
(i) force or violence; or
(ii) threat of force or violence;
(iii) any trick or false pretence.

1. Factual Dispute

2. Lawful Excuse

3. Lack of intent

County Court