Virgin stop testing after wing failure
In better weather conditions at the Spanish circuit, the red flags waved when the wing aboard Timo Glock's VR-01 single seater came off.
"We're missing one or two spare parts which will hopefully arrive this evening, so we won't be able to run for the rest of the day," said technical director Nick Wirth.
The problem is a major blow for the new British team, following Wednesday's rain and the bad weather that is apparently set to return on Friday.
In two days of testing, the car is yet to post anywhere near a competitive lap time.
The star of the first half of Thursday's dry running was Sebastien Buemi in the new Toro Rosso, followed by Jenson Button's McLaren, which has again been wearing some odd aerodynamic sensor appendages.
After a huge device drew some consternation on Wednesday, the team explained that it was "instrumentation to gauge flow structures".
Among the mere spectators on Thursday are Mercedes reserve driver Nick Heidfeld, as well as Felipe Massa who will take over from Fernando Alonso on Friday.
Rubens Barrichello also arrived in the early afternoon, after his Williams teammate Nico Hulkenberg spent time in the garage having an hydraulic leak fixed.