SAKHIR, Bahrain -- Alpine's Esteban Ocon set the fastest lap time on the second morning of testing in Bahrain as a number of teams encountered issues in the desert heat.
The second day of testing took place in 37 degrees Celsius (98 degrees Farenheit) heat, providing unusually hot conditions for both cars and drivers.
The most dramatic of the problems occurred on the Williams when the rear brakes of Nicholas Latifi's car caught fire. The first sign of trouble came when smoke started pouring from the rear wheels, but Latifi attempted to make it back to the pits.
He got as far as Turn 13 -- two corners from the pit lane -- when the left rear wheel buckled under the cornering load, causing the car to spin off into the run off area.
Flames engulfed the rear of the car once it stopped and a small explosion occurred as a marshal attempted to put out the fire. Both Latifi and the marshal were unharmed, but the issue put an end to Williams' running and the car has not left the garage since the incident.
McLaren continued to manage brake cooling issues during the second morning of testing after its track time on Thursday was also limited by brake problems. Although the team did not experience anything as dramatic as Williams' fire, Lando Norris was limited to 29 laps in the morning after just 50 laps during the whole of Thursday's running.
Norris was only driving on Friday because Daniel Ricciardo ruled himself out for a second day in a row because he felt unwell. Ricciardo fell ill on Thursday morning, but the team has confirmed he has not tested positive for Covid-19.
Sebastian Vettel stopped on track in the Aston Martin in the final hour of the morning, but quickly returned to the track once the car had been recovered, suggesting there was no major issue with the car.
Valtteri Bottas' Alfa Romeo also caused a red flag when his car stopped at Turn 9 in the final minutes of the session. The FIA had hoped to test its race restart procedure with a mock grid at the end of the session, but after lining up on the grid for an aborted start procedure, Bottas' car stopped on track on the following lap before the grid could reform for a race-style restart.
Ocon's fastest time was 0.4s slower than the benchmark set by AlphaTauri's Pierre Gasly on the opening day of the test, but the Alpine driver was using a tyre compound one step harder than Gasly (Ocon was on the C4 and Gasly on the C5) and Ocon set his time in much hotter track temperatures.
Harder tyre compounds tend to be slower over one lap, at the payoff of being more durable over longer runs.
Ferrari continued to occupy the upper reaches of the timing screens, with Charles Leclerc second fastest with a time just 0.090s off Ocon despite using the harder C3 compound tyre. The third fastest driver from the morning session was Max Verstappen, who set a time 1.598s off Ocon using the C2 compound.
Times at lunch:
1. Esteban Ocon - Alpine - 1:34.276 - 59 laps
2. Charles Leclerc - Ferrari - 1:34.366 - 54 laps
3. Max Verstappen - Red Bull - 1:35.874 - 45 laps
4. Sebastian Vettel - Aston Martin - 1:36.020 - 46 laps
5. Lando Norris - McLaren - 1:36.0354 - 29 laps
6. Yuki Tsunoda - AlphaTauri - 1:36.802 - 44 laps
7. Valtteri Bottas - Alfa Romeo - 1:36.987 - 25 laps
8. Mick Schumacher - Haas - 1:37.846 - 23 laps
9. George Russell - Mercedes - 1:38.585 - 67 laps
10. Nichoals Latifi - Williams - 1:39.845 - 12 laps