Since 9/11 it is a different world. You now get screened as you go through airports and tested for any sign of explosives. For mine sites every explosive must be accounted for and meticulous records kept.

It was not always so.

In 1971 Mount Isa Mines worker Francis Sorohan became a clueless accomplish in one of Australia’s greatest bomb threats. Initially charged as an accomplice, Sorohan was later released without charge with the head magistrate expressing he knew of a plan to extort money from QANTAS.

Sorohan was befriended by a man named Peter Macari who encouraged him to steal gelignite and detonators from the mine. Macari paid him $100 for the explosives which in 2023 was valued at approximately $1,300.

Two weeks after the hoax an examination of the gelignite and detonators used in the making of the bomb found they were also used at Mount Isa Mines. This led police to believe that the hoaxer either worked at or had worked in the mines.

So how did the hoax develop and how far did it go?

If it sounds like a Hollywood script that is because that is where the idea came from; a 1966 movie called Doomsday Flight gave Macari the idea.

Macari was born in Devon, England and was arrested in July 1969 on charges of indecent assault. He was on bail and awaiting trial when, a month later, he sold his elder brother his fish and chip shop.

Using a false passport he skipped bail and sailed to Sydney where he opened a small factory at Brookvale in Sydney producing fibre-glass boats.

The business was not profitable and during this time he became friends with Raymond Poynting who knew Macari by his main alias "Peter King".

Macari bought a "fitted-up van" and began to travel, heading north along the Queensland coast. It was in March 1971, while staying in Townsville, that he saw the film which highlighted the steps to take.

With the plan beginning to form Macari’s need for explosives saw him travel to Mount Isa where he befriended Sorohan.

With explosives in hand Macari returned to Sydney in May where he bought an altimeter (an instrument used to determine an object’s height above a certain point).

He then offered Poynting $50,000 in exchange for his help with the extortion. Poynting agreed and typed out three threatening letters detailing the instructions for the ransom – which were that the bomb would explode if the plane descended below 20,000 feet.

Macari’s initial plan was to extort a Pan American jet, but he found that Flight 755 from Sydney to Hong Kong was the only flight staying long enough in the air to make the plan work.

The night before the target of the hoax, Flight 755, was to take off the pair drove to a Hertz rental vehicle depot close to Kingsford Smith Airport. They stole car keys belonging to a Volkswagen Kombi to use as the getaway vehicle.

Around 2:00pm on 26 May the Federal Government's Aviation Department received a phone call from a mysterious man calling himself “Mr Brown”. He stated there was a bomb hidden on a Boeing 707 Qantas flight 755 from Sydney to Hong Kong.

The bomb was fitted with an altitude sensor that would trigger it if the airplane dipped under 6,500 meters. In return for $500,000 Mr Brown told authorities he would divulge the bombs’ exact location and how to dismantle it.

"But if you don't believe me," Mr Brown said. "Why not inspect Locker 84 at Sydney's Kingsford-Smith International Airport where I've placed a replica device?"

The Police bomb squad opened the locker and found three letters and a deactivated explosive device constructed out of unprimed gelignite and an altimeter-triggered detonator.

The first letter was addressed to Captain Bert Ritchie, a Qantas general manager, demanding $500,000 ransom in exchange for instructions on how to dismantle the bomb on Flight 755.

"If you don't pay, or if you interfere in any way, you will lose your plane. And this will be repeated," the letter continued.

The second letter repeated Mr Brown’s claim that an identical explosive device was hidden inside Flight 755.

The third letter warned the bomb would explode if the plane should descend below 20,000 feet (6,000m).

Authorities quickly established a radio link with the pilot of Flight 755.

Captain Ritchie was not present in the office so Qantas deputy general manager Phillip Howson spoke with Mr Brown at roughly 2:00 pm, 3:00 pm, and 4:00 pm.

At each phone call more information and instructions regarding the ransom were provided. Howson identified the voice as being English-accented.

Around 5:30pm Macari spoke with Howson again, relaying his instructions for the delivery of the ransom money; $500,000 in used unmarked $20 notes.

Police warned against paying the ransom but Flight 755 had been forced to circle in the air for over six hours. With a little over an hour of fuel left on Flight 755, Qantas agreed to pay.

The pilot of Flight 755 Captain William Selwyn was informed of the situation while flying over Dalby in Queensland. He was instructed to maintain an altitude of 35,000 feet.

Authorities initially planned to divert the plane to Canberra because it was the highest location in the country where the plane could land. The plane at first diverted to Brisbane and circled the city, escorted by an RAAF Phantom fighter-bomber jet.

Soon afterwards the plane was diverted back to Sydney, due to superior emergency services. While Selwyn made his way back to Sydney at minimum speed, the air and cabin crew searched the plane extensively for the bomb

The passengers were told the plane was returning due to a technical difficulty but they became suspicious when their personal belongings were searched.

In Sydney an identical plane was thoroughly searched for possible hiding places for a bomb. Their findings were radioed to Selwyn and his crew, who pulled off every conceivable panel and even ripped-up carpets and removed light-fittings.

Mr Brown told authorities that a yellow van would park outside Qantas company headquarters in Chifley Square at 5:45 pm, and that the driver would identify himself by shaking his keys out of the window.

He warned the van must not be followed, and any deviation from the agreement, would see him activate the bomb on Flight 755.

At roughly 5:45 pm the yellow Volkswagen Kombi stolen the night before arrived. The money was in two blue suitcases Captain Ritchie handed to the driver through the window of the van.

The suitcases were filled with $500,000 in new $20 bills from the Commonwealth Bank in Martin Place with the serial numbers recorded.

Although the bomber warned against police tailing the vehicle there were four unmarked police vehicles in the area. However they were never informed the handover was taking place though it remains unclear exactly what happened.

Resembling an episode of keystone cops detectives, who were planning to arrest Mr Brown at the handover, were accidentally locked in a lift.

"It was a very well laid plan," Police Commissioner Norman Allen said before adding. "Unfortunately, it didn’t go the way in which it was designed."

Soon after 6:00 pm, authorities received a final call from Mr Brown stating there was no bomb onboard Flight 755 so the plane began its descent around 6:40 pm.

The Boeing 707 landed safely at Sydney Airport.

Attention turned to catching the extortionist with a $50,000 reward for information leading to the capture of the hoaxer offered. Over 14,500 calls were received by police.

Phonetic experts were brought in and after listening to recordings concluded that he was an Englishman, likely from the Midlands, and likely a recent English migrant.

Police attempted to match that information with those that had a criminal record in Britain. They worked closely with Scotland Yard, Interpol, and the FBI to try and narrow down the list of suspects.

Sketches and flyers were released to the public but the trail went cold.

Two weeks later it was determined he gelignite and detonators used in the bomb were also being used at Mount Isa Mines.

Rather than sit on the money Macari and Poynting splurged on flash cars and in August police received a tip off from a service station attendant. He told them about a regular customer who suddenly rocked up in a white E-type Jaguar and a few weeks later in a tangerine Falcon GT.

Macari became a suspect at the same time when a young man who’d met him at 'The Wall' in the Sydney suburb of Darlinghurst came forward. The location was a well-known pick-up spot for Sydney’s gay community.

The young man described Macari as "repugnant and repulsive” with a "piece-of-s*** car". When Macari turned up with a new blue Chevrolet Camaro and plenty of money to burn the young man became suspicious and rang the police.

They played him a tape of the Qantas call and he identified Macari's voice as that of 'Mr Brown'.

Knowing Macari’s habits, he took them to 'The Wall', where they waited for him to cruise past in his distinctive car.

The pair were placed under surveillance and arrested on 4 August. 28-year-old Poynting showed there was no honour among thieves when he confessed to his role in the robbery and gave Macari up.

The next question was “where was the money?”

A bricklayer working on the Annandale property owned by Macari contacted police, telling them that recent work had been done inside the house by somebody else.

Police found $138,240 in $20 notes behind a bricked-up fireplace. In July 1973 police found $137,000 of the ransom money under the floorboards of a house in Balmain. Police stated that Macari had hidden in the house for a few days after the extortion.

That amounted to just over half the ransom and Macari told detectives the rest was taken by the real mastermind. He said a man called Ken was the head of a dangerous gang who put him up to the heist and took $220,000 of the ransom.

At trial Judge Staunton said upon sentencing, "You said you gave $220,000 to a person known as Ken, this statement I reject."

Macari and Poynting both pleaded guilty to charges of demanding money with menaces and stealing a motor vehicle. Macari was also charged with carrying a grenade in Sydney Airport.

Poynting was jailed for seven years and Macari for 15. However, Macari served only nine years before being paroled and deported to England in 1980 – on a QANTAS flight.

In 1972 Qantas held an auction where they sold the suitcases used in the ransom and the cars bought by Macari and Poynting. 

The remaining $244,000 has never been found and there is a belief that is may be hidden underwater in two safes off Bondi Beach

The Doomsday Flight film had triggered at least three extortion plots.

A few days before Macari and Poynting were arrested, a similar attempt was foiled at Denver. A week later, the US government urged 500 television stations to ban the film, telling them they would be “making the highest possible contribution to the safety of more than 60 million passengers.” 

A year later, in August 1972, newly minted Minister for Customs Don Chip, pressured by the Australian Federation of Air Pilots, banned a similar film, Skyjacked, “in the interests of the travelling public”.

“There are”, he explained, “enough crackpots and lunatics in the community who would be drawn to this film like a bee to honey.”

In November of that year, even without having seen the film, a slightly crazy man proved Chip’s point when he hijacked an Ansett Airlines Flight, wanting to “commit suicide in a spectacular way.”

Two years later there was another attempt to extort Qantas in almost the same way as Macari had done. Thankfully, it was done by a 21-year old painter from Drummoyne who instructed the police to drop off the money to his home address. It was another example of badly thought-out stupidity, but still alarming.

For this reason when authorities realised in 1985 that the whole Macari-Qantas saga was being made into a film, all hell broke lose. Questions were asked in the Senate, and Qantas actively tried to stop the movie being made.

They failed, but Network 10, who had invested a quarter of a million dollars into Call me Mr Brown, refused to screen it. It remained unseen until it came out on video in 1990.

But that wasn’t the end of it.

In 1970 young Englishman Billy Day went missing in Australia. When his parents read a newspaper report about Macari's release and realized he was the man referred to in Billy’s final letter.

Australian police flew to Britain at the family's request but Macari denied having met him. In 1998 police reopened a cold case into the disappearance of a young Englishman William Day and began asking questions about the alias Macari had used.

Billy, as his family called him, migrated to Australia in 1969 and worked his way around the country before arriving in Sydney in 1970.

His plan was to spend two years here, work hard, put some money aside, and then go home. In Sydney he moved into a flat at Bondi with Macari, who was using the alias Peter Brown, and another Brit.

He had consistently written home and in July 1970, wrote to his mother to tell her that he was driving with Peter Brown to Queensland in Peter’s van. He said he’d write once he arrived but no letter ever came.

While Macari returned to Bondi, Billy did not.

When the police investigating Macari for the QANTAS hoax followed the money trail they found the luxury cars he bought were in the name of William Day.

David Burt, Billy’s old travel companion, happened to see media reports mentioning that Macari had purchased a Jaguar under the name “Bill Day.” Alarmed, Burt contacted authorities to report that Day was a real person who had gone missing.

Police, assuming “Billy Day” was just another alias invented by Macari, ignored the connection. When interviewed, Macari claimed the name “Day” was fictional, like “Brown.”

Four months later in November Billy’s father Walter, alarmed by the silence, wrote to NSW and Queensland police alerting them to his son’s disappearance. Their inquiries drew a blank.

The letters the family had written to Billy were returned unopened a year later in a single large envelope. Walter took them to his local Police station who lost them, meaning potential fingerprints and DNA evidence was gone.

NSW detective Mark Murdoch flew to the UK to interview Macari, who at this time owned a fish and chip shop near Brighton. He denied knowing Billy and said the name William Day was just one of his aliases.

However, witnesses they spoke to disagreed, confirming the two shared the Bondi flat and that they had last seen Billy when he and Macari departed on the Queensland trip.

“Macari’s memory appears to be excellent if not exceptional. Interestingly, only when the author raised the subject of William Day did his memory fail,” Murdoch reported.

"Peter Macari had ample opportunity to cause the death of William Day and dispose of his remains.”

A coronial inquest was held into Day’s disappearance, but nothing conclusive came out of it. However the report said “it seems nothing short of incredible that police did not attempt to locate William Day".

They also discovered that despite the measures undertaken by the Day family, no formal record was ever made of their relative's disappearance in either Australia or the United Kingdom.

Macari was not extradited and allowed to continue to live his life in Britain.

Day’s bank account and identity may have been a tempting motive for murder; especially if detectives knew Macari was also the prime suspect in the 1967 murder of his own brother George in England.

George Macari was an adult with an intellectual disability who was in care at the Botley Park Hospital in Surrey when he disappeared in 1962. His body was found five years later buried about 25km from the hospital.

The cause of death was multiple head injuries and though it was ruled a murder, no arrests were made. When UK police reviewed the case in 2017 Peter Macari was the top suspect but couldn’t be interviewed because he had died four years earlier.

While there was not enough evidence to charge him in connection with either death, police concluded that it would not be unreasonable to believe that Billy Day had been killed, likely by Macari, sometime during or after their planned trip to Brisbane.

In 2019, nearly 50 years after his disappearance, members of Billy’s surviving family submitted DNA samples to assist in identifying any remains that might be found.

DNA samples were taken from the Day family but as yet no matches have been reported. So Billy Day’s remains have not been found and the case remains officially unsolved.