Australia has downgraded the aviation threat level to where it was before police uncovered an alleged terrorist plot amid expectations charges will be laid against those involved.

Prime Minister Malcolm Turnbull announced the move Thursday but said there would still be “enhanced” security measures at airports as a result of the plan to target an aircraft.

Turnbull said the decision to downgrade the threat level was made in consultation with intelligence and security agencies, including the Australian Intelligence Security Organisation (ASIO).

“We have outstanding security measures at our airports,’’ he told reporters in Perth. “They are going to continue to be enhanced, but they will be modified in a way that will cause less delays to the travelling public.”

Under upgraded measures introduced in Sydney a week ago and to other airports on Saturday, passengers had been asked to arrive two hours before a domestic flight and three hours before an international flight.

They had also been told to limit the what they packed in cabin and checked baggage.

They will now be allowed to turn up in accordance with airline policies in place before the threat emerged.

However, not all airline policies are the same and low-cost carriers can require an earlier check-in. There can also be a difference in recommended check-in times for business and economy passengers.

The Qantas Group said the decision to moderate the additional security measures put in place on July would reduce the time it took to get through an airport.

While Qantas is now asking passengers to follow its previously recommended check-in times,  it said they should ensure they arrived in plenty of time for their flight.

“The Qantas Group works closely with the Australian Government and intelligence agencies to make sure we have the right security measures in all the destinations we fly to,’’ it said in a statement. “The safety of our passengers and our crew is always paramount.”

The investigation into the threat is ongoing but one of four men arrested in raids in Sydney on Saturday has been released.

However, Turnbull said police had uncovered “very substantial evidence’.

“The commissioner, the federal police commissioner Andrew Colvin, has advised me that the investigation efforts are proceeding very successfully in terms of the gathering of evidence and that I should expect, and Australians should expect, charges to be laid in due course,” he said.

The Prime Minister would not comment on a report in The Daily Telegraph that an unwitting airline passenger had been used to take an improvised bomb to the airport packed in cabin baggage. The report said bag had been rejected as too heavy at check-in.

The move also comes after calls for security at airports to be further upgraded, including demands for passenger IDs and screening of ground workers.

The Australian and International Pilots Association argued its members were subject to tougher screening procedures than other airline staff because they were forced to go through security. It backed the introduction of US-style screening that requiring photo identification.

Asked about the calls, Turnbull said airport security measures were constantly under review and there were already strong security measures at airports which “have been enhanced and they will continue to be enhanced”.

“But we are very focused too on ensuring that we look after…. (and) respect the convenience of the travelling public as well,’’ he said.

Gulf carrier Etihad earlier this week confirmed that it was helping police with their inquiries but would not elaborate.

Air New Zealand has Brazil and the east coast of North America in its sights as it looks to replace its fleet of Boeing 777-200 aircraft with next generation long-range planes.

AirNZ chief executive Christopher Luxon told AirlineRatings on the sidelines of a CAPA Centre for Aviation summit in Sydney that the airline was looking at the Brazilian cities Sao Paulo and Rio de Janeiro as potential destinations to complement its existing service to Argentina’s Buenos Aires.

“We are very interested in trying to get ourselves further to the eastern seaboard of North and South America,’’ he said

“Locations like Sao Paolo and Rio de Janeiro and others on the eastern seaboard of America are really important for us.’’

The Brazilian destinations are outside the range of the airlines current fleet of Boeing 777s and B787-9s.

“We get there sometimes, we can’t always get home back across the Pacific Ocean,’’ Luxon said. “We’re about to go through a replacement process for our 777-200s — we’re obviously looking at aircraft that can get us into Sao Paulo and to Rio.”

The AirNZ boss said the airline planned to issue a request for information on replacements for the B77-200 fleet towards the end of this year with a request for proposals by the end of 2018 ahead of a competition between Boeing and Airbus.

The competition would pit Boeing’s 777X against longer range versions of The Airbus A350.

In the interim, Luxon said airline’s service to Buenos Aries was attracting many Brazilians, particularly young people heading to work in New Zealand’s tourism industry.

“Buenos Aries is a very good town in that it actually collects everybody versus in Brazil where you have six cities and you sort of have to knock off a little bit to get the same O&D (origin and destination) traffic,’’ he said.

AirNZ has been pursuing a Pacific Rim strategy under Luxon which has already seen the carrier forge alliances and significantly expand its own services within the region.

“When I started, lots of people would come up to me and say — I even might have read a CAPA report that said as much — that we were structurally disadvantaged,” he told the conference.  “We were an end-of-line carrier, two rocks at the bottom of the Pacific Ocean close to Antarctica, fly five hours you might hit 25 million people, all of them leisure travellers, how does any of this make sense?

“The bottom line was we said that’s rubbish — we are actually bang smack in the middle of the most exciting region in the world.’’

AirNZ’s expansion had been accompanied by a tight rein on costs to protect the airline’s balance sheet and provide the cash to fund the growth.

It has spent almost $NZ3 billion simplifying and upgrading its fleet, $NZ150m upgrading lounges and is investing heavily in digital capability.

In addition to Buenos Aires, new markets have included Houston, Beijing, Japanese destinations Osaka and Haneda and Vietnam’s Ho chi Minh City.

Luxon said the investment in Boeing 787-9 Dreamliners and B77-300s had allowed the airline to unlock the Pacific Rim and had seen its network grow by 35 per cent over the past five years.

“And this is giving us tremendous scale benefits because for the first time now in our history, in 77 years, we can now start to connect emerging parts of the world through new Zealand to other parts of the world,’’ he said.

“So if you think about it, the fastest way to get from China and South-East Asia to South America is through New Zealand.

’If you think about the fact we are three hours closer, and therefore can get three hours deeper towards the eastern seaboard of North and South America than you can from the eastern seaboard of Australia, we connect Australians to North and South America as a consequence very strongly.

“So it’s giving us a huge, huge capability and opportunities that we previously haven’t seen. We can go to double daily or triple daily services with more capital efficiency by virtue of aircraft asset rotation.’’

A key for Luxon has been to ensure that the experience on the carrier is consistent, with the same product in both aircraft and lounges so customers can rely on a consistent product.

Read our latest review of AirNZ.

The airline also talks to 4000 customers a month and has “mystery shoppers’” taking its flights and testing the booking process.

The push has paid off in terms of industry recognition and Luxon said customer satisfaction was now at record high levels.

Read: AIrline soars on award-winning service.

For years, Southwest Airlines confined its route structure to the U.S. mainland proper. Then it bought AirTran, and almost in an instant, it was a player in Mexico and the Caribbean.

Now comes news the low-fare juggernaut is continuing its slow surge south, making Indianapolis its 17^th international gateway. To be sure, Indy isn’t any mega-hub, but come March 10, 2018, it will see Saturday-only nonstop service to the Mexican resort of Cancun.

From March 8, 2018, Southwest adds a new route from its busy Fort Lauderdale/Hollywood, gateway to the Caribbean island of Aruba.

Polishing its U.S. Midwest product, there will also be a new domestic leg between Milwaukee and Houston Hobby, a prime Latin and Caribbean connection point for Southwest to places such as Cancun, Belize and Mexico City.

This new service illustrates the metered sort of expansion that’s a hallmark of the airline. JetBlue and Spirit offer a slew of service south, but Southwest’s measured approach indicates it’s in no particular hurry to be king of Caribbean.

Abu Dhabi-based Etihad says it is cooperating with Australian Federal Police about an alleged plot to take down an airliner with an improvised explosive device.

Media reports in recent days have suggested an Etihad aircraft travelling from Sydney to the Gulf was a target of a plan to smuggle the device on to a plane and possibly gas passengers.

Sydney tabloid The Daily Telegraph reported the plan was to put substances in a common kitchen meat mincer that may have exploded on board or gassed hundreds of passengers.

There has been no official confirmation of the reports and few publicly-released facts beyond Prime Minister Malcolm Turnbull’s initial comments that a major joint counterterrorism operation disrupted a terrorist plot to bring down an aircraft.

Australian Federal Police commissioner Andrew Colvin said over the weekend the attack planned to use an improvised device to target an Australian plane.

Colvin described the threat as “credible’’ and said authorities believed it was Islamic-inspired.

But he said there was no evidence to suggest airport security had been compromised.

Four men were arrested after a series of raids on Sydney properties on Saturday and one was released on Tuesday night without being charged.

A joint police statement released Wednesday said three men remained  in detention under

Three men remain in detention under and the investigation was ongoing, the statement said.

Etihad confirmed on Tuesday it was assisting police with the investigation.

“The Etihad Airways aviation security (AVSEC) team is assisting the Australian Federal Police (AFP) with its investigation and the matter is ongoing,’’ it said in a statement.

“Etihad is complying fully with the enhanced security measures at airports in Australia and monitoring the situation closely. Safety is the airline’s number one priority.”

Sources have told Australian media outlets that the intelligence that led to the raid came from Britain and that the plot was well advanced before Australian authorities intervened.

There have been delays and queues at Australian airports since authorities tightened security at Sydney Airport on Thursday and at Melbourne, Brisbane, Darwin, Perth, Adelaide, Canberra, Cairns, Gold Coast and Hobart airports over the weekend.

Travellers were advised to arrive two hours before domestic flights and three hours before international services.

They were also being asked to limit the amount of carry-on and checked baggage where possible to help ensure the efficiency of security screening.

Jetstar Group chief executive Jayne Hrdlicka said yesterday most customers had not seen a huge impact but the time to get through security screening had gone from two to three minutes to “maybe 10 minutes’’.

“The lines are fast and everybody’s happy to contribute,’’ she said after flying from Melbourne to Sydney for the CAPA Australia Pacific Aviation & Corporate Summit on Tuesday. “And if it improves safety and security then everybody’s for it.’’

There has been no indication yet of how long the increased security will last and what additional costs it might impose on airlines and airports.

Hrdlicka said it was hard to see where it would go but for the moment “everyone has risen to the occasion and we’re comfortable with where we’re at”.

“Safety and security are the most important things in the industry and I don’t think anybody’s going to argue with that,’’ she said.

The Jetstar boss said she was confident that the airline could handle any new security processes such as a requirement for domestic passengers to produce ID and options included biometric identification.

She said such a move would not affect the airline’s automated check-in kiosks.

“All through the US, almost airports now are predominantly kiosk -based check-in now even for international,’’ she said. “So what you do is you go through the kiosk process and then you go have your ID checked.

“it sounds like quite a big step but it’s been very easily integrated into a quite simple, efficient processes around the world.’’

Australia has tightened airport security after authorities foiled what they say was a plan to take down an airliner, with at least one report claiming the target was an international flight to the Middle East.

Passengers are being told to allow extra time and minimise cabin baggage when checking into airports after the New South Wales Joint Counter Terrorism Team (JCTT)  arrested four men in raids in several Sydney suburbs on Saturday.

Australian Prime Minister Malcolm Turnbull said security had been increased at Sydney Airport since Thursday and extended to all major international and domestic terminals overnight.

“I can report last night that there has been a major joint counterterrorism operation to disrupt a terrorist plot to bring down an airplane,” Turnbull told reporters. “The operation is continuing.”

The Australian newspaper said Monday it had been told by sources the plan was to attack the plane with “a non-traditional device” explosive device that would have used a toxic sulphur-based gas to kill or immobilise everyone on the plane. The newspaper said authorities believed the plan had been orchestrated by Islamic militants in Syria.

Transport Minister Darren Chester said additional security measures were put in place at Sydney, Melbourne, Brisbane, Darwin, Perth, Adelaide, Canberra, Cairns, Gold Coast and Hobart airports.

Both Chester and Turnbull urged travellers to go about their business with confidence.

“Some of these measures will be obvious to the travelling public, others will not,’’ Chester said. “The increased measures will include additional checks of cabin and checked baggage.

“These additional measures complement the security arrangements already in place and are being applied as an extra precaution, in coordination with counter terrorism raids in Sydney last night.”

Searches were conducted at five properties in the Sydney suburbs of Lakemba, Surry Hills, Wiley Park and Punchbowl on Saturday by Australian Federal Police, New South Wales Police and intelligence agency ASI0.

Australian Federal Police commissioner Andrew Colvin said the attack planned to use an improvised device to target an Australian plane.

Colvin described the threat as “credible’’ and said authorities believed it was Islamic-inspired.

But he said there was no evidence to suggest airport security had been compromised.

“Australia has some of the best, if not the best airport security arrangements in the world and we’re confident those measures are effective and would have been effective, in this circumstance,’’ he said

Colvin cautioned the investigation was “at very early stage” and that searches at four of the five raided premises were ongoing.

“And we anticipate they will be ongoing for many hours if not days,’’ he said.

The ABC reported it had been told police had found materials and items that could have been used to make a homemade bomb at a property in inner-city Surry Hills.

The broadcaster said it understood authorities believed the group was intending to smuggle the device onto a plane.  Seven News later said it had been told the target was an international flight tot he Middle East, possibly Dubai.

It is not clear how long the extra security measures will be in place and airlines have been texting and emailing passengers to urge them to be prepared.

There is no change to what can or cannot be carried on aircraft but travellers are being advised to arrive two hours before domestic flights and three hours before international services.

They are also being asked to limit the amount of carry-on and checked baggage where possible to help ensure the efficiency of security screening.

As expected, the Monday-morning surge in traffic caused long lines at major airports but passengers appeared to generally accept the need for tighter security.

The Qantas Group, which includes low-cost carrier Jetstar, said it was working closely with government and airport partners to implement the increased measures.

“Australia has very strong safeguards in place at its airports; these changes are about making them even stronger,’’ it said.

Virgin Australia said in a statement: “The travelling public can expect to experience an increased level of security scrutiny at the airport but they should not be concerned about these precautionary measures.

“As the measures place an additional burden on the screening system, it may take a little longer than usual to get through the process.”

US authorities warned of ongoing terrorist interest in targeting commercial aviation when they introduced a controversial ban on taking laptops and other large electronic devices as cabin baggage on direct flights to the US from airports in the Middle East and North Africa.

In a Q&A released at the time by the Department of Homeland Security, the US said it was concerned about terrorists “ongoing interest in targeting commercial aviation, including transportation hubs over the past two years, as evidenced by the 2015 airliner downing in Egypt, the 2016 attempted airliner downing in Somalia, and the 2016 armed attacks against airports in Brussels and Istanbul”.

“Evaluated intelligence indicates that terrorist groups continue to target commercial aviation, to include smuggling explosive devices in various consumer items,’’ it said.

The DHS  has since lifted the laptop ban but required airports operating direct flights to US destinations to have in place “enhanced” security measures.

These included a boost to overall passenger screening, heightened screening of personal electronic devices as well as increased security protocols around aircraft and in passenger areas.

Chester said security measures in place in Australia included passenger, cabin and checked-luggage screening as well as hardened cockpit doors, security-related cabin crew training and plain clothes in-flight security officers.

He said the government also worked closely with airport operators to ensure that physical security measures were in place to protect publicly accessible areas of airport terminals.

“This includes the design of airport infrastructure to reduce the impact of a terrorist attack,’’ he said.

“As the Prime Minister has said, the safety and security of the travelling public is the government’s number one priority.”

Qatar Airways has confirmed it will start double-daily Sydney services from February 13 with a  “tag”  flight connecting Australian capital Canberra.

The airline will use a 358-seat Boeing 777-300 aircraft to fly Doha-Sydney-Canberra and then Canberra-Sydney-Doha.

The big jet will be flying the short Sydney-Canberra hop alongside ATR and Q 400 turboprops but it will not be able to fly domestic passengers between the two Australian cities.

It will be competing for passengers with Singapore Airline’s direct flight between Singapore and Canberra.

Singapore recently retimed that flight to improve connections with other flights in its network and make the service more efficient.

Qatar had used up its rights under the current bilateral air services agreement to service Australia’s major gateway airports of Sydney, Melbourne, Perth and Brisbane.

However, it is allowed an additional seven frequencies a week to one of the major airports provided it operates the “via or beyond to a point in Australia other than Sydney, Melbourne, Brisbane and Perth’’.

“The services intended to be operated by Qatar Airways to Canberra via Sydney are accommodated under this entitlement,’’ a spokeswoman for Transport Minister Darren Chester said.

Qatar Airways group chief executive Akbar Al Baker described Canberra as an important addition to the global route map that further boosted ties between the countries.

“We are confident our highly-acclaimed product will appeal greatly to government, business and leisure travellers alike and we look forward to welcoming our passengers on board very soon,”  he said in a statement.