Fernando Alonso was quickest in a truncated opening practice session in Austin
Fog and medical helicopter problems allow only 45 minutes of running
By Mike Wise at the Circuit of The Americas
Last Updated: 18/11/13 4:39pm
First fog and then problems with the trackside medical helicopter were to blame, with the former enveloping the 5.513km Circuit of The Americas and causing a 40-minute delay.
Even so, cars were only on track for about 15 minutes before the session was red-flagged. The problem this time was technical, with drivers forced to twiddle their thumbs for another half an hour as a replacement 'copter was sought.
The lack of running was clearly a frustration because by this stage conditions were bright and sunny. Toro Rosso driver Daniel Ricciardo summed up the situation perfectly when asked by his engineer whether he was ready to go back out. "I've been ready for an hour and a half," was the reply.
It came as little surprise, then, to see every driver out on track as the clock ticked down, with Alonso emerging on top by 0.028s from McLaren's Jenson Button.
The Ferrari star was cleared to drive earlier this week after a trip over the kerbs during the Abu Dhabi GP injured his back and was sporting visible strapping during the session.
Williams driver Valtteri Bottas was third fastest ahead of Sauber's Esteban Gutierrez, with Mercedes pair Nico Rosberg and Lewis Hamilton fifth and sixth. The top ten was completed by Felipe Massa (Ferrari), Mark Webber (Red Bull), Nico Hulkenberg (Sauber) and Pastor Maldonado (Williams).
Romain Grosjean was next up, with stand-in team-mate Heikki Kovalainen two places behind in 13th place. Sergio Perez's McLaren sandwiched the Lotus pair.
Elsewhere, Daniil Kvyat's practice debut for Toro Rosso ended with the 16th fastest time, just a couple of tenths down on Ricciardo's best.
Both finished directly above Sebastian Vettel on the timesheets, although the World Champion - who was 2.3s off Alonso's pace - was running with a heavy fuel load.