Porto. Portugal’s second largest city, some 300 kilometres north of Lisbon. An historical centre located along the Douro River and declared a World Heritage Site by UNESCO in 1996.

So with their 14th century buildings and azulejos facades, how did Porto and Gaia, the municipality on the other side of the river, decide to host a competition featuring planes capable of slaloming at speeds up to 230 knots?

“Porto is a historical place with a lot of heritage, but the host city wanted to be seen as an innovative place,” explains Erich Wolf, the Red Bull Air Race general manager. “That’s what we provide.”

The event last visited Porto from 2007 through to 2009, proving popular with fans as they lined the riverbanks to witness the race. This weekend’s return is no different, with a total of 850,000 visitors cheering for the 14 propeller-driven machines.

To keep spectators and pilots safe, the entrance speed has been reduced. “It’s a very narrow place here,” explains Wolf, “so we ran simulations to calculate what the theoretical impact point of an out-of-control aircraft would be. Hitting a spectator is a no go, so we needed to reduce the entrance speed to 180 knots.

“We’re also staying well within a 150-meter safety line and avoiding certain turns where the theoretical impact point would lead us to the public area.”

That’s protecting people and buildings from a potential crash, but how about a less tangible impact – pollution?

“We’re not producing a lot of pollution compared to other emitters,” says Wolf. “But we’re planning for the future and are doing some research in regards to what’s in the fuel, to try and reduce pollution.

“Thinking well beyond that, there are several electrical engine projects going on globally and we’re observing that very carefully.”

Red Bull Air Race light aviation technology versus Porto’s timeless panorama – a bold association, but one that combines the best of both worlds. 

The Czech Republic’s Martin Šonka claimed the second race win of his career at the Red Bull Air Race in Porto, Portugal on Sunday and launched himself back to the top of the World Championship standings with only two races to go. In a Final 4 that set 600,000 hearts racing on the banks of the Douro River, Canada’s Pete McLeod captured second for the third race in a row, and Matt Hall of Australia clinched third.

Šonka – the only pilot in the Final 4 never to have raced in Porto – went first and threw down the gauntlet with 1:07.229. Fighting to retain his overall lead in the World Championship, the USA’s Kirby Chambliss then served up a net time of 01:07.141, but he incurred a two-second penalty that saved Šonka’s win and opened the door for the rest. McLeod’s finish was only a breathtaking 0.113 behind Šonka’s, while Hall’s third place was his first podium of the season after switching raceplanes this year.

The results were pivotal for Šonka, who earned his career-first race win and the top of the overall leaderboard at the season opener in Abu Dhabi, only to subsequently slip. He’s been locked in a title battle with the likes of Chambliss, McLeod and Japan’s Yoshihide Muroya all season. Now with only the two races in Germany and the USA remaining, the Czech ace is four points ahead of the consistent McLeod, who jumped to second overall. Chambliss is still in the running at third place with 47 points, and so is Muroya with 44. While the Japanese pilot’s sixth-place finish was impressive after extensive raceplane work limited his track time in Porto, the result was blow, dropping him to fourth overall. With just a 10-point gap among those four contenders – and 15 points available for a race win – tension is mounting fast.

“After the last three races where we got various penalties, it was simply time to fly again – and race again – and we won, so I’m really happy,” said an elated Šonka, whose best overall finish in four previous seasons was fourth. “Of course we would like to win the title, but the others are fast, and with two races left there are still a lot of points on the table. So nothing is decided yet, and we have to wait until the end of the season.”

Spanish pilot Juan Velarde did not participate on Race Day in Porto because after making modifications to their raceplane, the weather prevented Team Velarde from completing necessary testing of the modifications.

In two weeks, the Red Bull Air Race makes a speedway shift with a return to Germany’s Lausitzring on 16-17 September 2017. It’s the home race of reigning World Champion Matthias Dolderer, who will be looking for a comeback after finishing eighth in Porto.