SINGAPORE - Two weeks ago, Qatar Airways chief Akbar Al Baker accused Changi Airport Group (CAG) of having copied Qatar's ideas in the design of Changi's Jewel.
Since he began his tenure as Qatar Airways chief in 1997, Mr Al Baker has not been shy to publicly put down his competitors.
Here are five other instances when he was in the media spotlight for his comments.
1. 'Most definitely' better than Singapore Airlines
In an interview with The Straits Times in 2014, Mr Al Baker said Qatar Airways was "most definitely" better than Singapore Airlines (SIA), and warned that the gap between the two would get wider with time.
Speaking from the business-class cabin of Qatar Airways' Boeing 787 on display at the Singapore Airshow, he boasted: "I don't think that there is any airline operating into Singapore, including Singapore Airlines, that offers this (Qatar's) high standard of product."
He added that Qatar Airways provides "the best value for money" in almost all aspects, from flying the most modern aircraft to offering top-end in-flight products at attractive fares.
At this year's World Airline Awards held on June 18 in Paris, Qatar Airways came in at the top spot for the world's best airline while SIA came in second, perhaps partially vindicating Mr Al Baker's 2014 assessment.
The competition is closer than he would admit, though. Last year, SIA came in first to Qatar Airways' second.
2. Only men can do 'challenging' jobs
In June 2018, Mr Al Baker sparked accusations of sexism after he said only a man could do his "challenging" job when fielding a media question on gender inequality in Middle East aviation.
Eliciting loud groans of disapproval from journalists in the room, he said of Qatar Airways: "Of course, it has to be led by a man, because (the chief) is a very challenging position."
Qatar Airways later issued a statement from him to quell the controversy, putting his answer down to lightheartedness. The statement then went on to emphasise the airline's track record in hiring and promoting women, which it said made up 33 per cent of its workforce.
Many were unconvinced though, given, as The Guardian put it, the airline's "abysmal reputation for its treatment of its predominantly female cabin crew".
3. 'Grandmothers' on US airlines
In 2017, Mr Al Baker said in a speech in Ireland that United States airlines were "crap", partly because their passengers were "always being served by grandmothers".
He then boasted that "the average age of my cabin crew is only 26".
Amid a backlash condemning his comments for sexism and ageism, he later apologised, pleading carelessness.
4. 'Unpatriotic, weak and unethical'
In 2015, amid a spat between American and Middle Eastern airlines over alleged unfair competition, US Delta Airlines chief Richard Anderson implied that Middle Eastern airlines had links with terrorism, prompting Mr Al Baker to retort.
In a rant reported in Dubai magazine Arabian Business, Mr Al Baker said Mr Anderson was "working against the interest of his own country", "has no dignity", "has no ethics" and had "a weak personality".
Later, in a move that aviation experts said did not make economic sense, Qatar Airways also announced it was launching a route from Doha to Atlanta, the hub of Delta.
Mr Al Baker's reasoning? To "rub salt in the woulds of Delta".
5. 'We want to attract people of a higher standard'
Mr Al Baker has more than once tried to influence Qatar's tourism industry, saying this year that the country would not grant visas to its "enemies", a reference to Egyptian nationals.
The Qatari government later distanced itself from Mr Al Baker's comments, even as the diplomatic dispute between Qatar and Saudi Arabia, the United Arab Emirates, Bahrain and Egypt continued unabated.
In 2016, Mr Al Baker also said backpackers were not wanted in Qatar because "we want to attract people of a higher standard".
Preferring people who "want to see the culture and are very keen on the arts side of tourism", he added that "backpackers are just there to lie on the beach and spend as little as possible".
It is unclear what the Qatar government thought of his comments, given that thousands of backpackers, many of whom arrive from Australia, visit the Middle East every year.
Sources: The Straits Times, The Guardian, BBC, New York Times, Arabian Business, The Daily Mail