Friday practice for this weekend's Eifel Grand Prix was cancelled after fog prevented the medical helicopter from operating during both the morning and afternoon sessions.
The two 90-minute practice sessions failed to get underway and were eventually called off by the sport's governing body, the FIA. Low cloud in the local area meant the medical helicopter was unable to fly to the Nurburgring's designated hospital in Koblenz in case of an on-track emergency.
Under FIA regulations, a Formula One track session can only take place if the transit time to the designated hospital can be guaranteed in under 20 minutes.