David Coulthard endured his second big crash of what could be his last season in Formula One yesterday, prompting an investigation by the stewards and the possibility that Red Bull could be banned from tomorrow's Malaysian Grand Prix because their cars are unsafe.

Coulthard managed only six laps in the first session of Friday practice when his car suffered a fault to one of its steering arms, resulting in the front right wheel failing to respond as the 36-year-old Scotsman tried to take a corner at speed.

His Red Bull RB4, designed by Adrian Newey, slewed off the track before recrossing the racing surface at right angles. As it hit the edge of the tarmac, the car suffered catastrophic damage, with both front wheels and the front wing exploding off the chassis.

The extent of the damage mirrored similar consequences for Coulthard's car when he was involved in a crash with Felipe Massa's Ferrari during the Australian Grand Prix a week ago. On that occasion, Coulthard hit Massa as the Brazilian was trying to overtake on the inside at a corner. While the Ferrari continued the race unaffected, the Red Bull suffered severe failure in its suspension and chassis and looked as if it had fallen apart.

Speaking after yesterday's smash, Coulthard said that he was not worried about his safety as word spread in the paddock that Christian Horner, the Red Bull team principal, along with Newey, had been summoned by Charlie Whiting, the race director, to explain why the cars should be allowed to race tomorrow.

“Mechanical failures are part and parcel of grand prix racing unfortunately,” Coulthard said. “We did 10,000kilometres in testing in the car. It was just a new part which did just six laps. It was just a fault in the manufacturing process and game over. There was so much damage and, with the regulations banning us using a spare car, it was impossible to fix in time.”

However, the former McLaren Mercedes driver also remarked that he was lucky the accident happened at the Sepang circuit, which has plenty of run-off area, unlike a track such as Spa in Belgium, where grandstands are much closer to the racing line. “I am glad it happened here rather than Spa ... otherwise you'd be picking bits of me out of the grandstand right now,” Coulthard said. “Formula One is a dangerous sport. Things occasionally fail.”

Red Bull were asked by the stewards to compile a report into the accident, demonstrating that the car's suspension is up to the job and that it is not, as the rules put it, “of dangerous constructions”. The report was due to be considered this morning, after which a decision will be taken on whether or not Coulthard and Mark Webber, his Australian team-mate, will be allowed to race.

Horner said that he was certain the cars were safe, while Newey explained that a manufacturing error had caused the failure in the steering arm. “We had a track rod end failure, which caused the accident with David earlier. We know what the problem is and are confident we will be OK for the rest of the weekend,” he said.

Over at Renault, Nelson Piquet Jr, the rookie driver, was savouring a good day in Malaysia after a woeful debut weekend in Australia, where he missed much of Friday practice after spinning and retired from the race after starting second from last. This time, Piquet ran throughout the day and was seventh quickest in the morning session, just behind Fernando Alonso, his illustrious team-mate.

“I did a lot of laps today and I was able to complete the planned programme, which has really made a big difference,” Piquet said. “The fact that I know the circuit also helps and I feel comfortable.”