The track is evolving and the times they are a tumblin'.

Max Verstappen is on the softs and is second-quickest on the timesheets after his first flyer. Oscar Piastri is third in the Mclaren on the same tyre, but Fernando Alonso shoots to the top on the red rubber with a 1:33.639.

Max Verstappen is first up on a flying lap on the soft compound, while George Russell has opted for the mediums for his opening hot run and goes quickest with a 1:34.531.

Over in the Ferrari camp, Charles Leclerc, who turned 28 yesterday, flags an issue with his car. "There's oil smell," says the Monegasque driver as he heads back to the pits.

The two Haas drivers, Esteban Ocon and Ollie Bearman, are the only two cars out on track at the moment. A shot of the crowd shows plenty of umbrellas up as fans try to shade themselves from the roasting temperatures in Austin this weekend.

Here come the medium and soft tyres, ready for some qualifying simulations. Drivers get two bites of the pole cherry at the United States Grand Prix.

McLaren CEO Zak Brown is speaking to Sky Sports on the pit wall but there's still no exact explanation of what these repercussions are for Lando Norris. Brown adds they're trying to manage this title battle between their drivers, so I guess we'll just have to wait and see what happens this weekend.

What do you think McLaren's 'sporting consequences' will be? We've got sprint qualifying coming up after this practice session, so will Lando Norris pay his repercussion debt to the team in that shorter fight for pole? Our eyes will be firmly peeled.

Meanwhile, Norris is quicker than his team-mate Oscar Piastri and is second to Lewis Hamilton on the timesheets. The gap between the McLaren and the Ferrari is over half a second.

Kimi Antonelli can rest easy now, knowing he's got a contract at Mercedes for the 2026 season. The rookie's attention today, though, is fixed on the only Williams left on track - Alex Albon. The two cars reach the final corner and Antonelli is unhappy with the Thai-Brit driver's positioning. "That was quite bad from Albon," the Italian tells his pit wall.

Andrew Benson
BBC F1 correspondent in Austin

McLaren have said there will be consequences for Lando Norris for that incident with Oscar Piastri in Singapore. What they haven't said is what those consequences are, although I have learned today that they are sporting in some way. We'll have to keep an eye out to see the sorts of things it could be. I'm guessing it could be the order in qualifying, or a tow maybe.

Image source, Getty Images

Esteban Ocon, like Carlos Sainz, is also returning to the garage with an issue. The Frenchman goes across the gravel and flags a problem with his brakes as he tries to control the car. His engineer calls him home and the data searches begin.

The clock says there are only 28 minutes left of this one and only Austin practice session, so a gearbox issue for Carlos Sainz may leave his Williams mechanics scrambling to get him back up and running for sprint qualifying.

Lando Norris improves on his latest lap and goes second behind Lewis Hamilton with a 1:35.397 on the C1 hard.

Lewis Hamilton has stayed in the Ferrari garage for now but Max Verstappen and George Russell are both banking more laps around COTA before tonight's sprint qualifying.

Over at Williams, this isn't looking good for Carlos Sainz. The Spaniard is out of the car with his race helmet off. His engineer told him "do not push, do not push" as he headed into the pits, then added the team are going to investigate "a potential issue with the gearbox".

Andrew Benson
BBC F1 correspondent in Austin

This circuit has a bit of everything, which is why the drivers love it so much. Actually I'm a bit gutted because I was offered a hot lap yesterday by Williams and I had to turn it down because I was too busy. I've regretted it ever since!

Cars are heading back out on track after that short delay. While it wasn't a long stoppage, with only one practice session this weekend, drivers and teams need to make the most of this hour, every second counts.

Session will start in one minute. Run if you want a cup of tea etc.

Yellow flagpublished at 18:54 BST 17 October

18:54 BST 17 October

The debris has come off the back of the Aston Martin of Lance Stroll, after the Canadian ran wide. Charles Leclerc's engineer was one of the first to tell his driver to stay off the kerb at Turn 19.

Red flagpublished at 18:53 BST 17 October

18:53 BST 17 October

OK, it looks like the stoppage is for a bit of debris at the penultimate corner.

Red flagpublished at 18:52 BST 17 October

18:52 BST 17 October

A red flag is showing on the timing screen, but as the telly is currently showing an advert for Argos, I've got no idea what it's for. We'll all find out together shortly.

The hard tyres are on for Lewis Hamilton and his prancing horse, mechanical this time, takes him to the top of the timesheets with a marker half a second quicker than fellow multiple world champion Max Verstappen. It's a 1:34.857 for the seven-time champ.

Image source, Getty Images

Isack Hadjar is finding it tricky to tame his Racing Bulls on his first time around the Circuit of the Americas in a Formula 1 car. The Frenchman needs the assistance of the escape road at Turn Five, before twitching a few corners at Turn 11.

Lewis Hamilton is on a flying lap in his Ferrari and is purple in the opening two sectors...

1. Max Verstappen (Red Bull) - 1:35.426

2. George Russell (Mercedes) +0.132

3. Yuki Tsunoda (Red Bull) +0.329

4. Lando Norris (McLaren) +0.360

5. Carlos Sainz (Williams) +0448

Andrew Benson
BBC F1 correspondent in Austin

Max Verstappen is one of those Formula 1 drivers who is a force of nature, a bit like Fernando Alonso for example. They are just unstoppable - there is something about them that drives them relentlessly forward. He's a very difficult man to divert from a path. It's to do with the sheer scale of his talent and the sheer force of his will.