"Whenever there is a tragedy, the first question I ask myself is, 'How did it happen?' and then, 'Is that going to be me next?'" he says.

Fornabaio had 2,700 aerobatic flying hours to his name, performed at about 25 air shows a year and was considered one of the best pilots in the sport. Can Chiang explain a crash like that? He begins to answer, and then thinks better of it.

"I think it's a completely different perspective once you're in the seat, getting thrown around. I don't want to be the judge."

Chiang began flying at the age of 13, in Wales - hence his British accent - where he lived with his mother while his father stayed in Hong Kong.

"We had a farmhouse among the mountains and every Sunday morning these Tornadoes - very fast jets from the RAF [Royal Air Force] - would come buzzing around my house. As a little boy, when you see that, you just think, 'If that's a job, I'm doing it'."

After taking lessons at Haverfordwest School of Flying, in central Wales, Chiang earned his private pilot's licence at the age of 17 and, two years later, was hired by a major international airline in Asia.

"In Hong Kong, it's very unusual to fly so young," he says, "because the general aviation facilities here are not as mature as overseas." Although on the aerobatic circuit, starting early is the norm - "Pete McLeod [the Canadian Red Bull Air Race pilot] can't even remember when he first got into a plane, because his dad owned a hangar."

(I look this up after our meeting: McLeod was, according to his official online biography, three years old when he had his first flying lesson.)

On being hired as a commercial pilot, Chiang returned to Hong Kong, where he was bought a flat by his parents, who own Xian-based compressor parts manufacturing firm Champion Aviation Dynamic Technology (his dad once flew planes, too). The company's motto is, "Where precision meets experience", which could just as easily be Chiang's mantra in the sky.

"Life was a little bit like being a rock star," he smiles, of becoming one of the youngest pilots in the world, if not the youngest, to fly the "queen of the skies" - a Boeing 747-400. "I worked 10 days a month, had friends who were always off [work], too, and it was very nice to get a pay cheque."

What is the starting salary for a 19-year-old airline pilot?

"I will never forget flying to San Francisco, in the United States. We landed mid-afternoon and went straight to a bar, but security asked to see my ID. I was with three pilots who were all over 40, but I couldn't get in. I thought, 'I just flew 400 passengers across the Pacific Ocean but I can't come into your bar?'" he laughs.

Today, Chiang has 2,200 flying hours (300 aerobatic, the rest commercial) to his credit, has flown 38 aircraft to six of the world's seven continents and has risen to the rank of first officer - essentially, the co-pilot.,

Half-way through the interview, Chiang hesitates and asks if I will do him a favour. Could I be discreet when mentioning which airline he flies for? His aerobatic career isn't one he advertises at Chek Lap Kok because - as he puts it - "a commercial pilot is expected to have a very different mentality to an aerobatic one". We agree on the wording "a Hong Kong carrier".

"The way you make decisions is very different when you are responsible for 400 people to when you are by yourself. I'm sure passengers wouldn't appreciate it if I flipped the plane upside down," he laughs. (The 2012 Denzel Washington movie saw a pilot save a commercial jet by doing just that, so perhaps it depends on the circumstances …)

"It's funny, there are days where I jump in a Triple 7 [Boeing 777] in the morning, then into an Extra after lunch." The two experiences, he says, are very different.

Aerobatic flying is "complete freedom, like adding a pair of wings to your body", he says. "The controls are so sensitive, you can gain 3,000 feet in 30 seconds; it gives me adrenaline. It's a 3D feeling of flight. People talk about flying, I don't think [being in charge of an airliner] is truly flying - you're travelling."

Chiang bought his US$300,000 Extra 300L in 2013; sponsorship from his parents' company, which he has a hand in running, helped foot the bill.

"Flying is not a cheap sport," he admits - especially in Hong Kong, where fuel costs three times as much as in South Africa, for example, where the pilot keeps his Extra.

What's more, the SAR government is hostile to general aviation, he says. This month things got a little frostier, with the Hong Kong Aviation Club, the only organisation in the city that trains pilots to obtain a private licence, having been forced to close down its flying operation at the old Kai Tak airport. Furthermore, fixed-wing aircraft can only operate out of Shek Kong Airfield, in the New Territories, once run by the RAF and now under the strict jurisdiction of the People's Liberation Army. Non-military aircraft are granted access only at weekends, weather permitting.

"We really feel like the Hong Kong government doesn't care about what we're doing," says Chiang. "Because flying is perceived to be a rich man's hobby, it's not on the government agenda to support this sport. But there are a lot of youngsters, like myself, who are not in the elite class but have a desire to fly. If I had been raised in Hong Kong, it would have been impossible to achieve what I have, because flying availability is so limited."

Even from Shek Kong, Chiang says, "because of limited air space, I can't get a lot of height - surface to 3,000 feet. It's not enough to do manoeuvres."

The two-seat monoplane Chiang keeps hangared in Johannesburg was designed in 1987 by Walter Extra, an award-winning German aerobatic pilot, and was built by Extra Flugzeugbau in Germany. It burns 1.5 litres of fuel per minute (a litre in Hong Kong costs HK$35) but, Chiang says, he offsets his carbon footprint by advocating for the most fuel efficient routes when flying airliners.

"You're burning 140 litres of fuel per minute then, so the savings I make there last a few hours of [personal] flying!"

Aerobatics - the practice of flying loops, rolls and other spectacular manoeuvres - has been a sport for nearly 100 years, and before the second world war was an Olympic category. Technological advances, such as the development of carbon fibre, which allows lighter planes to carry more powerful engines, has seen the sport develop recently.

"It's only in the past 10 years we've been about to pull 10Gs [10 times the force of gravity] and the wings will stay on," says Chiang. "It's the fastest growing motor sport in the world.

"That's what they call it; it's like driving a Formula One car - you're even sat in the same reclined position. The difference is one is in the air and one is on the ground. Actually, aerobatics is a lot more dangerous: we're driving faster than F1 cars do (400 km/h compared with 322km/h, at maximum speeds), and have very little crash protection." He adds that F1 drivers pull 4G or 5G during a race, whereas in aerobatics, 9G is common. "Nine Gs for me is nine times my body weight, that's like having 700kg sitting on you - basically, an entire cow - while you're trying to perform extremely precise manoeuvres."

To stop himself from passing out, Chiang practises a breathing technique that involves squeezing his legs and abdominal muscles to prevent blood from rushing from his head to his legs as his plane tears through the sky. Is that a fool-proof technique?

"Not at all," he says, poker-faced. "You just have to practise."

Intermediate Aerobatic Championship is the biggest event Chiang has competed in thus far, although it was not the first time he had represented Hong Kong; he was once the fly-half in the under- 20s rugby squad, playing at the Hong Kong Sevens in 2007.

The FAI competition saw 60 pilots from 20 countries convene on Mossel Bay to compete for the title, and marked the first time China had been represented on the world stage in the sport. As has so often been the case for Chiang, he was the youngest flyer present.

"Coming to meet the other pilots, you really feel the pressure," says Chiang, smiling as though pressure is something he enjoys. "For all the teams, except the Russians, it's just our hobby, so we don't get paid. Even if you win the prize money, it's barely enough to cover your air ticket out there."

The pilots were each required to fly over an area measuring 1,000 metres by 1,000 metres, which was marked on the ground, and to a vertical limit of 1,000 metres, and lower limit of 200 metres to 100 metres, depending on the category.

On the morning of the flight, Chiang refused to speak to other pilots, he says. He took a brief walk along the harbour looking not ahead, towards the Indian Ocean, but upwards, to evaluate the sky conditions. Then he turned off his phone and meditated, before strapping into the cockpit.

"The qualifier went exceptionally well. I only expected to place mid-field, so when I placed third at the end of the sequence I was very happy."

In the next round, Chiang competed with pilots who had five to 10 years competitive experience, against his two years. It was, he says, the best flight of his life.

"I was scoring at 83 per cent, and the winner had 80 per cent. But, unfortunately, I had a penalty that cost me the championship. I came below the minimum height, which wiped out points."

Chiang came third.

He grimaces. "I was ecstatic to bring home a medal," he says, with-out a hint of ecstasy, "but without that penalty I would have been the world champion."

Chiang's sights are now set on the Red Bull Air Race. Established in 2003, the race takes place through an international obstacle course. To qualify for the 2016 season, Chiang will have to compete in the next Unlimited World Aerobatic Championship, which will take place in France this August.

"It's an explosive sport where each heat is a minute-and-a-half," says Chiang, suddenly invigorated, the memory of defeat fading. "The winning margins can be a thousandth of a second."

Last year, Red Bull stipulated that all pilots must fly with the same race engine, without modification, meaning taking the title is down to airmanship alone.

Navigating a light aircraft between the goalposts, many laid out on spectacular waterscapes, such as Manhattan bay, in New York, and Putrajaya Lake, in Putrajaya, Malaysia - although not always; Ascot Racecourse, in Britain, has been a location - requires incredible precision: "It's a bit like parallel parking at 50km/h."

Chiang pulls his smartphone from his pocket and plays me a video of the New York Red Bull race in 2010. Making the roar of a McLaren racing car, in full throttle, the planes buzz between the Statue of Liberty and Lower Manhattan.

"Wouldn't it be amazing if Hong Kong was to have that?"

The organisers, he says, wanted to put a stop in the city - something that would have raised Chiang's prospects of being able to compete; "if there's a race in Japan, for example," he explains, "they want a Japanese pilot in the mix" - but the government wasn't supportive of the idea, even though the competition has an impeccable safety record (there have been no deaths in the Red Bull series). Similarly, a leg scheduled to take place in Beijing last year was axed.

"I've been as a spectator, but I want to be the first Chinese pilot in the competition.

"It's my dream to step into a race plane and show Hong Kong people what a Hong Kong-born pilot can do over Victoria Harbour," he says.

As if to demonstrate that point, Chiang begins to act out one of his favourite manoeuvres, the knife-edge spin, with his phone. For this gyroscopic crowd-pleaser, "the aeroplane is basically travelling sideways but falling out of the sky, in circles", he explains, moving his Samsung in that motion. "It's a very dangerous manoeuvre, but when all the smoke is coming out the back of the plane it is spectacular."

It looks terrifying; as if control of the plane has been totally lost; like it's a dead bird falling out of a tree, until that final moment when the pilot pulls it into a swooping ascent.

Does Chiang consider himself a daredevil?

"No, because I never strap into a plane thinking that there is a high chance there will be a fatality. If I deem it dangerous, I take more altitude to achieve a goal. Daredevils take risks to achieve their goals," he says. It is a question the now solemn Chiang has contemplated before.

But isn't the sport inherently dangerous, a magnet for the dare-devil personality?

"Yes, and I am an adrenaline junky. I love flying. There are pilots who are daredevils, but I try to plan everything I do. Most accidents happen when you don't plan."

We have arrived back at the notion that aerobatic crashes can be explained, and potentially avoided. Chiang acknowledges he can't totally think the risk out of aerobatics and he understands the power of probability: the more shows he performs in, the more risk he is shouldering.

"To go professional with this, and make money from it now, I'd have to start doing a lot more air shows," he says. "I'm not prepared to do that for a career.

"I don't want to take the fun out of my fun," he smiles, "Or what will I do for fun?"

By the same author: Barack Obama's half-brother in Shenzhen