Ahead of today's second free practice session, the air temperature is 35 degrees C, and the track temperature is 50 degrees. It remains hot and sunny, with barely a cloud in the sky.

As the lights go green the long queue at the end of the pitlane, headed by Adrian Sutil, sets to work. In moments there are ten drivers on track.

Vettel clearly has a problem, the German drives at snails pace around the circuit, desperate to get back to the pits. In an effort to avoid the Toro Rosso, Davidson goes ludicrously wide, kicking up a great cloud of dust.

Fisichella goes quickest, then Kovalainen, but Hamilton is already on a hot lap. Sure enough, the McLaren driver crosses the line at 28.914 to go quickest.

A 28.947 sees Alonso go second, as Kubica goes fifth ahead of Barrichello.

Having made it back to the pits, Vettel enjoys a cooling drink in the Toro Rosso garage as his crew works frantically on his car.

Ten minutes into the session, Felipe Massa heads down the pitlane, the first appearance by a Ferrari driver in this session. Despite going wide in the third sector, the Brazilian posts 29.932 to go fifth.

Next time around Massa improves with 28.884, but Raikkonen has already banged in a 28.762 to go second to Hamilton.

No sign of David Coulthard yet following his little bonfire at the end of the first session. The Scot and Vettel are the only drivers that haven't posted times in this session.

Twenty-two minutes into the session the red flags come out, though it's not clear why. Then it is revealed that there is a loose drain cover at the exit of Turn 10. Rubens Barrichello is one of several drivers to have encountered it. Charlie Whiting and Herbie Blash head off in the safety car to inspect the errant drain cover. Those bloody drains are playing up again.

Amazing isn't it? This multi-billion pound sport comes to a standstill due to a loose drain cover. We watch, with some amusement, as the FIA officials stamp on the loose drain covers.

After twenty minutes, officials confirm that the session will resume at 14:50, the teams therefore having lost 28 minutes of practice.

Sure enough, at 14:50 the lights go green and fifteen cars stream on to the circuit, among them the big four, Alonso, Hamilton, Massa and Raikkonen.

A 29.148 sees Trulli go sixth, as Kovalainen goes wide. Elsewhere, Yamamoto enjoys a 'detour' across the Turkish countryside, as Webber improves to thirteenth.

With less than half-an-hour remaining, there's still no sign of either Vettel or Coulthard, with neither driver having posted a time.

Hamilton and Alonso are both on track, the Englishman still heading the timesheets.

Button complains of understeer and oversteer, "you don't really know what the car's going to do in any particular corner," he laments. The Englishman is currently fifteenth, three places behind his teammate.

Schumacher goes third and Trulli fourth, but Raikkonen and Massa are both on track, both on the softer compound.

Coulthard and Vettel are both given the all clear, and within minutes the Scot has gone twelfth (29.689) and the German twentieth (30.801).

In the first session both BMW drivers posted their best times on the harder compound. When both Ferrari drivers fail to improve on the softs it seems to confirm that the harder option is the better of the two, at least for now.

Hamilton is on a hot lap, breezing past the charging Alex Wurz as though the Austrian is on a Sunday afternoon cruise. That said, for the next couple of corners the Williams driver sits on the McLaren's tail.

Massa goes quickest in the second sector, but a poor final sector sees him fail to improve. As the Brazilian heads back to the pits, teammate Raikkonen comes out to play. Within moments the Finn is all crossed up.

It's all over for Davidson. The Englishman goes off into the gravel finally hitting the tyre barrier. It's a low impact accident but its enough to bend his suspension. Moments later, Kovalainen goes wide, as does Raikkonen, who is running just behind the Renault driver.