Stephen Byron has also slammed the retrospective application of quarantine requirements for travellers returning from COVID-19 hotspots, describing them as "despicable" and an "overreaction".

Appearing before a Senate inquiry into the aviation sector on Wednesday afternoon, Mr Byron said "ad hoc" responses to small outbreaks across Australia had sapped confidence in interstate travel.

Brisbane, Perth and Victoria have all been subject to snap lockdowns in 2021 after the virus, including cases of more infectious variants, slipped out of hotel quarantine.

South Australia was thrust into a state-wide shutdown in November.

In each case, the virus' spread was quickly contained and restrictions were relaxed.

During the lockdown periods, the other state and territory governments have imposed restrictions on travel from the hotspots, forcing the cancellation of flights.

Asked by Labor senator Tony Sheldon to offer a view on what was needed to support Canberra Airport and the aviation sector through the next phase of the pandemic, Mr Byron was blunt.

"What's needed is confidence in travel; that people, whether they travel for business or leisure, can travel without being put into quarantine domestically," he said.

"What's needed is not citywide lockdowns when there is a single case. What's needed is for there to be very localised lockdowns and patience. If you do need a citywide lockdown for 24-hours while you assess and catch up your contact tracing ... then [it should be] immediately released.

"Three and five-day lockdowns when the cases after day one are zero and after two days are zero are disgraceful.

"City lockdowns are worse than border closures. The border closures are like kryptonite to aviation and travel, the citywide lockdowns are worse."

Mr Byron saved his most stinging criticism for rules subjecting travelers who had already returned from a hotspot to even harsher restrictions than people in locked-down zones.

For example, in January Canberrans who had returned from Brisbane were forced to home quarantine, while people in the locked-down Queensland capital were still allowed outside for essential reasons such as exercise and grocery shopping.

"To be frank, it's despicable aside from an overreaction," he said.

The Canberra Airport chief has previously praised the ACT government's approach to borders as the "gold standard", and said other jurisdictions should follow its lead and only impose restrictions for as long as they are absolutely necessary.

ACT Chief Minister Andrew Barr has expressed confidence that the vaccine rollout now under way would signal the end of state border closures.

Mr Byron also told the Senate inquiry, which is examining the future of the sector post-COVID-19, that income from Canberra Airport's aviation activities was down 98 per cent at times during the crisis.

But he said the airport had been be able to navigate the unprecedented crisis because of its strong property assets, which account for half of its income.

In earlier evidence to the inquiry, Qantas and Rex Airlines made the case for further federal government assistance after the JobKeeper program ends next month.

Treasurer Josh Frydenberg on Wednesday said the Morrison government was "very conscious" of the sector's need for continued support.

"There has already been substantial support but the government recognises the need to retain a domestic sovereign capability in our aviation sector," he said.

"We're all very much focused on other initiatives that we may be considering with respect to aviation and other areas of need."

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