Welcome back for second practice at Istanbul Park. Lewis Hamilton was nearly a second faster than anyone in the morning session but the suspicion is that nobody else was really trying. Sutil had a huge accident so it will be interesting to see if his car gets repaired in time.

The track was really lacking grip in the first session but as the cars continue to run and the soft compound Bridgestones come out expect the lap times to plummet.

There are plenty of photos for you to browse on the left of the screen. Unfortunately none of the Sutil accident yet - the TV cameras also missed it - but will keep updating them as our agencies upload them from the circuit.

Fell free to add your thoughts and make fun of my comments by clicking the link at the bottom of the commentary box. You can also ask questions and I will do my best to answer.

Karun Chandhok on his problem earlier that saw him crawling around the track very slowly: "My speed with the throttle problem on the back straight was the same as when I cycled on Wednesday - 33kmh !!! Hehehe..."

Force India is working hard to repair the damage to Sutil's car: "Some damage to the front right suspension of Adrian's car but the team is working to repair it in time for FP2 at 14:00 this afternoon."

That'll be 10 minutes time then.

Kovalainen had a good first session and was within 0.5 seconds of the Toro Rosso of Alguersuari. Here are his thoughts: "First session ok, no problems, tried different ride height settings in car, T8 dominates setup direction. Next session tyre comparison."

Virgin acknowleges there is work to do after both drivers were beaten by Chandhok's HRT: "Engineers currently poring over data. Definite areas we can improve, but not possible during FP1."

Bruno Senna is happy to be back in his car after Yamamoto's run in it this morning: "Sakon got good mileage and my car ran reliably. Now I'm ready to start my weekend."

Stuart asks: "Hi. Has anyone sighted the Redbull 'F' duct intake on Vettel's Redbull? Where is it located?"

The inlet is in the top half of the airbox, no McLaren-style snorkel in front of the cockpit for them. Vettel was controlling it with a pad on his wrist to block a duct in his cockpit. Overall, it looks closer to Ferrari's system than McLaren's or Mercedes'.

The lights go green and the session is under way

The lights go green and the session is under way

Bruno Senna is first out but most others are staying put.

It is a sweltering 30C at the circuit and the track temp is up to 51C at the start of the session.

Senna's car is bobbing around under braking. It looked very shaky in Yamamoto's hands this morning and not much better with Senna this aftenoon.

Petrov sets the fastest time so far with a 1:30.049, that will be beaten pretty sharpish.

Kobayashi is off the track at turn 8. The car bottomed out, he got overtseer and it snapped round on him. No damage to the car but the tyres look flat-spotted.

Kubica sets a 1:29.558 ahead of Hamilton.

Sutil is still out of the car without his helmet on but he might still have another 20 minute wait before he gets out on track.

A big slide for Button through the final corner but he sets a new fastest time. Although that is immediately beaten by Hamilton by about 0.3s

Button clocks the fastest time with a 1:28.931.

We're still waiting for the Red Bulls and Schumacher to make an appearance. Apparently the team is changing a water pipe on Vettel's car.

Button is back in the gararge now after an eight lap run. His time has just been beaten by Hamilton with a 1:28.921

Schumacher is out on track now and is already fighting it through the first and second corners. And on his second attempt he runs well wide into turn one and cruises for the rest of the first section of the track.

There is a tail wind coming into the first corner of 3.1 metres per second and that could be causing a few issues for the drivers. Turn 1 is tricky at the best of times but the drivers are having to adjust because a lap is ruined right from the off if they make a mistake there.

Update from Renault: "We have a busy working schedule this afternoon, everybody's heads down. We also have a new front wing this weekend."

"Balance much better than this morning and the grip has improved," reports Liuzzi.

Rosberg is just cruising out on track and not going at full speed. We suspect he is gathering aero data - Schumacher and Vettel were doing the same in the first session.

Mark Webber is now running the F-duct, using his wrist to cover the duct. He goes fourth fastest, 0.621 off Hamilton.

Don't forget you can send in your questions and comments by clicking on the link below.

Webber is now third fastest but fastest of all through turn 8. You could hear on the on-board footage that he was running almost flat through turn 8. Very impressive and very worrying for its competitiors. Remember, they are not even running soft tyres or a light fuel load yet.

Sauber suspect the tyres work best on lap one and then start to go off on the second attempt. An interesting coversation between de la Rosa and his mechanics over the radio.

Petrov runs wide at turn 8 on the soft tyre.

Nenad says: "It seems that Ferrari is out of this track, quite strange how slow they are in S1."

Jason asks: "Is the macca faster this weekend?"

It should be quicker because the track suits the car much better. Don't be fooled though, it is still early in the weekend and Red Bull have a tendency to hold something back until Saturday.

Fabio: "I'm a little worried about Ferraris. How do they look like on circuit? Any major problems?"

They haven't completed a huge amount of laps and we haven't seen much of them on the TV. No obvious problems and they haven't yet run soft tyres. I wouldn't worry until after final practice. Ferrari often prepare for the race on Friday and qualifying on Saturday.

Greg says: "According to speed trap data, Button and Hamilton have top speed - F-duct seems to work well. But the next on the list are HRTs and Renaults, which don't use such system. Could you comment this?"

HRT is easy to explain - they don't have any downforce full stop so it's almost like running a permanent F-duct. Renault is more surprising because their engine is not one of the most powerful either. Remember, an F-duct not only allows a faster top speed but also to add more wing for the corners. Also I suspect McLaren is the only team 100% happy with their system.

Adam: "Can the mclaren beat the Red Bulls?"

I certainly wouldn't put money on it. Maybe later in the season but the gap in Spain was too big to close in just three weeks. But Red Bull have had reliability problems, so who knows...

Back to the action, we've got Webber and Schumacher out on track but they aren't running the softer tyres yet.

Liuzzi runs wide at turn 8 for the second time this session. The car was visibly bottoming out so he still has plenty to think about. In other Force India news, Sutil has now completed five laps.

Jason asks: "Are both Red Bulls using that F-Duct? And if so what is the speed traps like?"

They are both running F-ducts but I can't tell you where they are in the speed trap times because my display only shows the top 6 cars...

Replays are showing the cars through turn 8, it's great to watch. The Ferrari looks stable the Sauber looks terrible. But despite that the Ferraris have set slower times than the Saubers. I expect that is a result of fuel loads rather than anything else.

Nico Rosberg is about to set his first timed lap. He's been doing aero runs so far but is about to do a hot lap on hard tyres... He goes sixth fastest, just 0.050 off team-mate Michael Schumacher.

Rosberg is hooked up in the first sector but is struggling later in the lap and remains in sixth place.

Hamilton is now out on the soft compound, as is Vettel.

Vettel goes fastest by 0.082 on the soft tyres. Hamilton was faster in the final sector, Vettel in the middle sector.

Alonso third fastest on the soft tyres, he just got baulked by Schumacher in the final corner. Schumacher is out on the softer tyres now, as are most of the runners.

Button fastest of all now by 0.310 seconds over Vettel. He set a time of 1:28.280 with a bit of a mistake in turn 8 - he had a great first sector though.

The Ferrari of Massa is off at turn 8 and he has wrecked his soft tyres. He just got a little too wide on the astroturf and the rear of the car came out.

For those asking, FOM do not allow us to display times on our live updates.

Vinoo asks: "How do the Merc's look through Turn 8? Have they improved their pace compared to the three teams in front? Are they any closer to the leading pack…"

Schumacher is taking a wider line through turn eight, missing a the first two apeices but nailing the last one. It seems to be going well but it is nowhere near as nailed as the Red Bull - they are quite comfortably flat. As for where they stack up against the top three, I think it is a little too early to tell. They are certainly in touch but I doubt they will be as competitive as in Q2 at Monaco.

Vlado: "i'm combining your page with formula1.com where i can see also live times"

A fine suggestion.

Of the front runners, just Rosberg is out on the track now. But he is on a longer run on hard tyres.

Ferrari: "Felipe aborted his run on soft tyres while Fernando's one was spoiled by the traffic at the end."

That translates to Massa spun off and then held up Alonso and Schumacher coming back onto the track.

Alonso is 0.445 off Button's best lap, Massa is 2.689 off.

Kobayashi is still having major problems in turn 8, the car is twitching and bottoming. Not good.

Adam asks: "How could Button beat Hamilton? It isn't common. Will it change?"

It'll be tough. He says that he is still not 100% happy with the car so I think we can expect him to close slightly as the season wears on. But the best way for him to beat him is with his head - like he did with strategy in Australia and China.

Red Bull is still reporting problems with a water pipe on Vettel's car. It looks as though there could still be a few reliability problems for that car.

Hamilton is back out on track on the soft tyres.

But Hamilton is 6 seconds off the best time, presumably running an early race simulation on the soft tyre to see how long it holds up.

Webber is now within 0.1 of Buttons's best time but I think that was set on his last run. He is now 4.6 seconds off Button on the soft tyre and on what is presumably heavy fuel.

Sutil is just coming back into the pits after another run. He has a pad strapped to his wrist to use the F-duct on that Force India.

Now the top five in the speed traps are all teams running F-ducts. Button 311 KPH, Hamilton 311 KPH, Alonso 309 KPH, Massa 309 KPH, Liuzzi 308 KPH.

22 cars out on track now with just five minutes remaining.

Webber has stopped on track and is rolling backwards off the track. Plenty of smoke coming out of the back and it sounded as though the engine let go after a gear change.

Webber is directing the marshals and is getting very irrate that they aren't stopping the car from rolling backwards. The team also thinks it's the engine that has let go.

Back on track we've got a matter of seconds remaining and nobody looks likely to beat Button's time.

As the chequered flag comes out, Chandhok spins off at turn eight but no damage to the car.

For those asking, Webber's engine blow up won't be penalised the drivers have eight engines to last the season and they can blow them up and use them as they please as long as they don't exceed that quota.

So the drivers make some practice starts and head back to the pits. That's the end of our live coverage today. Thank you for joining us and we'll be back for Saturday practice bright and early tomorrow morning. Make sure you check the website throughout the rest of the day for driver reaction and all the latest news.