Hello and welcome to the first practice session for the Turkish Grand Prix. In just a matter of minutes of the drivers will be heading out on track to get their first taste the circuit in this year's cars.

Of course the big question this weekend is whether anyone can catch the Red Bulls and you have to say the answer is probably a resounding "no". On the plus side the sun is out and the track conditions are near perfect for this first session so we should see plenty of running.

The cars are now out on track with the Lotus of Jarno Trulli leading the way.

As usual the drivers are running their preliminary checks. Out the pits, one careful lap and back into the garage.

Japanese driver and ex-Super Aguri man Sakon Yamamoto is out in the HRT replacing Bruno Senna this morning. He is the team's test driver and Senna will get the car back in the next session.

All the cars, with the exception of Webber's Red Bull, have been out on track. Vettel is out at the moment but taking it very easily as he checks everything is working on his new chassis that he has named Randy Mandy.

Alonso's Ferrari is up on jacks in the garage as the whole team swarms around it. Ferrari says: "Fernando is back in the garage as well, having done the double installation lap."

We've had news from the pit lane that only Vettel's Red Bull is running the F-duct, Webber will have to wait for the system. The team has already admitted it might not run it this weekend.

Schumacher completes a very slow lap, obviously still a few system checks for that car.

Don't forget you can send feedback or ask questions by clicking the link at the bottom of the commentary box.

Paul di Resta will not be driving this morning for Force India as the two race drivers are being given a bit more track time to get used to the car's updates, including a new F-duct.

Liuzzi is already pushing hard, using all the kerbing on the exit of turn 8.

Di Grassi is out in his new car, this is the first race he has the updated Virgin with the larger fuel tank.

James in the USA asks: "I know F1 is all about the sanctioning fees for Bernie, but with the past attendance at Turkey, how long can we expect to see F1 continuing to go there? Also, is attendance expected to be any better this year?"

It's a very good point and the answer it could be pulled as soon as next year. Turkey isn't a crucial markert for sponsors and car manufacturers like China is so there won't be a much in the way of protest if it goes. The grandstands are empty this morning and there isn't a huge amount of hope that it will change as the weekend continues. It's a shame because it's a great circuit.

25 minutes in and we have the first timed lap, set by Yamamoto in the HRT, a 1:37.620. His car looks terrible under braking and was bucking around over the bumps. A bit of the car may have fallen off because there is debris on the track.

Pat asks: "Do you think the Red Bulls and their Renault engine's lack of top-end speed could see them struggle against Mercedes/Ferrari power down the back straight into turn 12, or do you think the RB6's superior cornering could give them an edge through 8 and onto the straight?"

If Red Bull don't get their F-duct running they could be way down on speed on the back straight. But I suspect the car will be so much quicker everywhere else that it won't matter and, like you say, the other cars won't be able to get close enough through the corner leading onto the straight, turn 9. I hope I'm wrong and the likes of McLaren and Ferrari have made gains, but if the gap is anything like it was in Spain I'm not too optimistic.

The Lotuses are now out setting times and Trulli goes fastest for about a second before his time is beaten by Alguersuari.

We;ve just had confirmation that part of the rear wing did come off Yamamoto's HRT

"Do you think Vettel's last two races have been hampered by his old chassis maybe damaged? I think he will be back in front of Webber from now on." Stan, Australia

Vettel admitted yesterday he was a little relieved to find that there was something wrong with his car, so yes, I do think he will improve. But we must not take away from Webber's performances over the last two races. Hopefully it'll be a really tight battle this weekend.

Trulli runs wide in turn one, just struggling to get that Lotus turned in.

Chandhok is slowly coming to a halt and reports over the radio that the engine has cut off. He is coasting around the track, trying to get back to the pits and his team tells him the throttle has failed.

And he just about rolls it back to the pits, a tad dangerous, but he makes it back over the white line so his team will be able to push him.

Remco asks, "Now that HRT and Dallara have ended their partnership, is it realistic to expect modifications on the chassis soon in order to improve the car?"

They say they will make updates but I don't think it will be anything substantial. Unfortunately that means they will continue to drop off the pack.

Back on track, Vettel is fastest of all with a 1:30.840, 1.231 ahead of Alguersuari.

The Toro Rosso driver said the track was very "green" (lacking grip) to start with but is starting to improve.

Hamilton and Massa have also set times, within 0.5 of Vettel.

Kubica is now quickest with a time of 1:30.471. To put in perspective the official lap record here is 1:24.770.

Hamilton has now taken the top spot with a 1:29.673 only to be beaten by 0.049 by team-mate Button.

Nico Rosberg came back into the pits but it looked like a bit of a late call by the Mercedes driver and he stopped briefly in the pit lane before he reached his garage.

Hamilton sets a lap 0.962 faster than anyone else. The times are starting to drop now.

Meanwhile Alonso clocks a time 5 seconds down on the McLaren. Cleary there are some very different programmes going on out there.

Sutil makes a bit of a mistake at turn 3 and uses part of the plentiful run-off area around this Istanbul Park track.

Petrov is also getting the car crossed up in the chicane heading onto the long back straight.

A replay shows Button having to make a correction in turn 8, just a small one but he will want to get those kind of mistakes ironed out before qualifying.

Hamilton still has the quickest lap but Button is the fastest through the speed trap at 312KPH. Liuzzi with his new F-duct is also quick through there with a speed of 311KPH. Hamilton is also clocked at 311KPH. Fourth is Kubica 307KPH, fifth Vettel 306KPH and Alonso sixth 306KPH.

Kubica locks a tyre into turn 1 and runs wide as a result. It looks as though the track is still a long way from its best. It will improve a lot as more cars go out and rubber goes down over the course of the weekend.

On board footage of Hulkenberg sees him missing the first three apices of turn 8, still work to do on his set-up because he is 3.5 seconds off the pace on that lap.

For the second time today, Trulli runs wide at turn 1 and rejoins the track. Lotus is the fastest of the new teams so far but Kovalainen has the edge over Trulli.

Mike Gascoyne offers an explanation for the time difference: "Jarno has a very high-mileage engine for today which is costing him quite a bit of laptime and topspeed compared with Heikki"

Sutil is struggling at the moment: "Adrian reports a lack of grip on the track, working through a couple of set up changes for the next run," says Force India.

Vettel joins the list of drivers to run wide in turn 1 and is currently over a second off the pace of Hamilton. But don't be fooled by the times, they are all trying different things and the track is changing all the time.

Despite Petrov's dramatic moment earlier, Renault says he is happy with the car so far: "Vitaly reports some understeer in the slower parts of the track. He's happy overall saying 'the car is stable'."

Virgin: "Track now looking a lot better - earlier Timo was reporting it's dirtier than other years. And oh, it's hot!"

Air temperature is 28C to be precise.

Lots of cars back on track now, including Hamilton, Button, Rosberg, Schumacher, Vettel, Kubica and Massa.

Hamilton is also struggling in turn 8, misses the second apex and has to back off. He's 5 seconds off his best so may well be starting a long run in preparation for the race. He has 9 laps left in his stint but may well be carrying much more fuel than is needed to complete that distance.

At the moment the times aren't changing that dramatically and nobody at the front of the field is setting fastest sectors. As usual long runs are the order of the day in Friday's running.

Schumacher very calmly says he struggling over the radio. His team responds that the wind has picked up but can't give a definitive reason for that loss of lap time.

Force India: Tonio goes out for final run this morning, Adrian out shortly"

That must be a little delayed as Sutil is out now and still struggling with his balance judging from the pictures we are getting.

So there is still no sign of the times improving, Webber is over 3 seconds off through the second sector.

Chandhok is back on track after that earlier throttle problem but his car is still squirming around.

Lotus update: "Both cars out for last runs, running to the flag and then practice starts on the grid. Not possible to do starts at the pit exit here."

Di Grassi's poor time at the bottom of the timesheets can be explained by the team working on installation laps in his new car. He goes quicker than Glock with his next lap but both Virgins are 2 seconds plus off the Lotuses.

Sutil has had a big accident. It looks like turn 8 and the front wing and tyres are hanging off that Force India. Confirmation that his accident was on the exit of turn 8 at 170 mph. There isn't a full replay of the accident but it looked very nasty. He is fine but the car will need a lot of attention before the next session.

So with a yellow flag there is even less of a chance anyone will beat Hamilton.

The session ends and Hamilton's time remains 0.962 clear at the top of the timesheets.

He set a 1:28.653, ahead of Button on a 1:29.615, Schumacher 1:29.750, Rosberg 1:29.855, Vettel 1:30.061, Kubica 1:30.061.

Thankyou for joining us, make sure you check back for second practice 2.5 hours time. We should see a better indication of how the teams line up and hopefully find a reason for Sutil's accident towards the end of the session.