Acts of indecency on an aircraft.

On 15 July 2026 the Australian Federal Police announced that a man was to face a NSW court after allegedly committing an act of indecency on a domestic flight the day before. The charge is a matter for the court and the man is entitled to the presumption of innocence. This article does not comment on that case. It uses the news to explain the law that applies whenever an offence is alleged on board an Australian flight.

The point that catches people out is the source of the law. The offence is an ACT offence, prosecuted federally, for conduct on a flight that never went near Canberra. That is not a mistake. It is the design of the Crimes (Aviation) Act 1991 (Cth). We set out how it works below, then look at the offence itself and how a charge of this kind is answered.

What law applies to crimes committed on a plane in Australia?

A plane in flight is a hard place for criminal law to reach. It moves between States and Territories, sometimes over the sea, in a matter of hours. If the criminal law of the ground below applied, the rules could change several times on a single trip, and a jury might have to decide which State the aircraft was over at the moment of an alleged act. Parliament avoided that problem by writing a single Commonwealth statute for offences on aircraft.

The Crimes (Aviation) Act 1991 (Cth) creates its own serious offences, such as hijacking, destroying an aircraft, and prejudicing the safe operation of a flight. But it does not try to list every ordinary offence a passenger might commit. Instead, section 15 borrows a ready-made body of criminal law and applies it to acts on board a covered aircraft. You can read the Act on the Federal Register of Legislation.

Why is an offence on a domestic flight charged under ACT law?

Section 15(1) works by a legal fiction. It asks whether the act, if it had happened in the Jervis Bay Territory, would have been an offence there. If it would, the person is guilty of an offence under the aviation Act, carrying the same penalty as the borrowed offence. The criminal law in force in the Jervis Bay Territory is the ACT's Crimes Act 1900 and the ACT's Criminal Code 2002. So the practical effect is that ACT criminal law governs conduct on the flight.

The section applies to what the Act calls a Division 2 aircraft. In plain terms, that takes in aircraft on interstate flights within Australia and aircraft flying to or from Australia. A flight from Perth to Sydney is an interstate flight, so the plane is a Division 2 aircraft and section 15 applies. That is why an alleged act on that flight is charged as an offence against section 60(1) of the Crimes Act 1900 (ACT), by way of section 15(1) of the aviation Act.

The choice of ACT law is deliberate. The ACT is the seat of federal power, and its criminal law sits closest to the Commonwealth. Borrowing one law for the whole national airspace means the same rules bind every passenger on every covered flight, whether the plane is over Western Australia, South Australia, or New South Wales when the alleged act occurs.

What is an act of indecency without consent?

Section 60(1) of the Crimes Act 1900 (ACT) makes it an offence to commit an act of indecency on, or in the presence of, another person without that person's consent, while reckless as to whether the person consents. The maximum penalty is 7 years imprisonment. Where the act is committed in company with another person, or is otherwise aggravated, the maximum rises to 9 years. You can read the section on the ACT legislation website.

An act of indecency is not defined by a fixed list. The law asks whether a reasonable person would regard the act as indecent, judged against contemporary community standards. It usually means conduct with a sexual character that offends those standards. Touching another person in a sexual way without consent can fall within it, and so can indecent conduct done in another person's presence. The line between an act of indecency and the more serious offence of sexual assault or sexual touching turns on the nature of the contact.

Consent is central. The ACT moved to an affirmative consent model in 2022, so consent means free and voluntary agreement, communicated by words or conduct, and it is not to be presumed from silence or a lack of resistance. We explain that reform in our note on the 2022 consent laws, and the principal ACT sexual offence in our article on sexual intercourse without consent in the ACT.

What must the prosecution prove?

The prosecution must prove several things beyond reasonable doubt. First, that the accused did an act that a reasonable person would regard as indecent. Second, that the act was done on or in the presence of the other person. Third, that the other person did not consent. Fourth, that the accused was reckless as to whether the person consented, meaning the accused was aware that the person might not be consenting and went ahead anyway.

Because the charge runs through section 15 of the aviation Act, the prosecution must also prove the aviation element, that the act was done on board a Division 2 aircraft. The Act makes that a matter of absolute liability, so the accused's belief about the aircraft's status does not assist. What remains in dispute in most cases is the conduct itself, consent, and the accused's state of mind about consent.

Can you be arrested for your behaviour on a domestic flight?

Yes. The pattern is familiar from the media releases the Australian Federal Police issue after these flights. Cabin crew report the conduct, the aircraft radios ahead, and AFP officers meet the plane at the gate. They interview the passengers and crew, take statements, and arrest the person where the evidence supports a charge. A first court appearance often follows within a day, in the State where the plane landed.

The aviation Act is not limited to indecency. It reaches assault of crew, offensive and disorderly conduct, endangering the safety of the aircraft, and interfering with the crew's duties. Many of those matters run through the same section 15 mechanism, so an assault on a fellow passenger is charged as an ACT assault offence in just the same way. Our note on common assault covers the assault elements that arise in these matters.

Who investigates and prosecutes offences committed on aircraft?

The Australian Federal Police investigate offences on aircraft and at airports, and the Commonwealth Director of Public Prosecutions runs the case in court. Even though the offence borrows ACT law, it is a Commonwealth charge, so it is handled by the Commonwealth prosecutor and the Commonwealth sentencing rules in Part IB of the Crimes Act 1914 (Cth) apply to any sentence. The matter is usually heard in the courts of the State where the aircraft landed, which is why a Perth to Sydney flight ends up before a Sydney court.

How a charge of this kind is defended.

The defence starts with the evidence of the act. These matters often turn on brief events in a confined space, with accounts from the complainant, nearby passengers, and crew. The reliability of those accounts, the seating layout, the lighting, and whether anyone had been drinking are all tested. A person who was asleep, unwell, or moving in a cramped cabin may have made contact that was not indecent and not intended.

Consent and recklessness are the next questions. The prosecution must prove the accused knew the other person might not be consenting. Where the contact was fleeting or ambiguous, the accused's state of mind is genuinely in issue, and the burden stays on the prosecution throughout. Intoxication can cut both ways, and how it is treated depends on the fault element the prosecution has to prove.

Where the evidence is strong, the work moves to outcome. An act of indecency covers a wide range of conduct, and the sentencing range is broad. Early advice, a careful account of the surrounding circumstances, and, where it is warranted, an early plea, all shape whether the result is a fine with a conviction, a good behaviour order, or a term of imprisonment. A conviction for a sexual offence can also carry reporting consequences, which is a reason to get advice before the first court date.

Frequently asked.

What law applies to crimes committed on a plane in Australia?

The Crimes (Aviation) Act 1991 (Cth) applies. For ordinary offences such as assault or an act of indecency, section 15 picks up the criminal law in force in the Jervis Bay Territory, which is the Crimes Act 1900 of the ACT, and applies it to acts on board an aircraft on an interstate or overseas flight. Conduct on a domestic flight between two States is charged as an ACT offence, prosecuted by the Commonwealth.

Why is an offence on a domestic flight charged under ACT law?

A plane in flight crosses State borders, so no single State's law fits the whole trip. Parliament chose one body of criminal law for all covered flights. Section 15 of the Crimes (Aviation) Act 1991 applies the law of the Jervis Bay Territory, which is the ACT's Crimes Act 1900, so the same rules apply on every domestic flight whatever States it passes over.

What is an act of indecency without consent?

Under section 60(1) of the Crimes Act 1900 (ACT), it is an act of indecency to do an indecent act on, or in the presence of, another person without consent, while reckless as to whether the person consents. An indecent act is one a reasonable person would regard as indecent, usually sexual conduct that offends community standards.

What is the penalty for an indecent act on a plane in Australia?

The borrowed offence sets the penalty. An act of indecency without consent under section 60(1) of the Crimes Act 1900 (ACT) carries a maximum of 7 years, rising to 9 years where it is committed in company or otherwise aggravated. Actual sentences range from a fine with a conviction recorded to imprisonment, depending on the facts.

Can you be arrested for your behaviour on a domestic flight?

Yes. Cabin crew can radio ahead, and the Australian Federal Police can meet the aircraft on landing, interview passengers and crew, and arrest a person where there is evidence of an offence. The AFP treats offences on flights as criminal matters, not just breaches of airline policy.

Who investigates and prosecutes offences committed on aircraft?

The Australian Federal Police investigate, and the Commonwealth Director of Public Prosecutions runs the case. Because the charge is a Commonwealth matter under the Crimes (Aviation) Act 1991, Commonwealth sentencing rules apply, and the matter is usually heard in the courts of the State where the aircraft landed.

To speak to a criminal defence lawyer, call Aaron Kernaghan on 0421 717 019.

This article is written by Aaron Kernaghan, criminal defence lawyer at Good Legal Lawyers, as at 15 July 2026. It is commentary and reflects the personal opinion of the author only. It is not legal advice, it is not a substitute for advice on your own matter, and it does not purport to be accurate or complete. Any matter referred to may be before the court and any person charged is presumed innocent. For advice on a specific matter, contact Aaron Kernaghan on 0421 717 019 or contact the firm.

More criminal-law commentary by Aaron Kernaghan.

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