In WEC (World Endurance Championship), in case it is not necessary to deploy the safety car, but it is judged that it is necessary for safety reason, full course yellow (FCY) is deployed.
If full course yellow is deployed, a message is displayed on the timing monitor, and yellow flag is waved and FCY board is displayed at the all observation posts.
The car speed is limited to 80km/h, and the driver must from a single row without overtaking.
During full course yellow is permitted to pit in, but it is not permitted to digest the drive-through penalties or penalty stops.
The end of the full course yellow is notified to the driver and a message is sent to each team by timing monitor. At observation posts, yellow flag and FCY board is removed and green flag is waved.
14.5 Neutralisation of the race: Full Course Yellow (FCY)
14.5.1 Placing the race under FCY
The Race Director may declare a Full Course Yellow period if he decides that this is necessary for safety reasons.
Once under FCY, cars will slow down to 80kph, in single file, and maintain their distance to the car in front and the car behind.
Overtaking is strictly prohibited under the FCY.
All marshal posts will display a waved yellow flag and a board with the indication FCY.
Any car being driven unnecessarily slowly, erratically or in a manner deemed potentially dangerous to other drivers at any time whilst the FCY is in use, will be reported to the stewards. This will apply whether any such car is being driven on the track, the pit entry road or the pit lane exit road.
14.5.2 Access to the pit lane under the FCY
The pit lane entry and exit remain open and cars are free to pit.
Cars going into the pit lane may overtake cars that are on the track once they cross Safety Car Line 1.
Cars exiting the pit lane may overtake other cars until they reach Safety Car Line 2.
On the pit lane entry and exit roads, the maximum speed is also limited to 80kph.
14.5.3 End of the FCY period
Once the problem(s) is/are solved, the Race Director will return the track to green; this is done by posting a message on the monitors.
At this stage, all marshal posts will replace the yellow flags and FCY boards with waved green flags. Racing and overtaking will normally resume without restrictions, regardless of the positions of the cars relative to one another and to the Line.
14.5.4 FCY and Safety Car
A FCY period may be followed by a Safety Car intervention if the problem remains unsolved and safety may be at risk.
14.5.5 Stop & Go, penalty in the pit lane under the FCY
Unless the driver was already in the pit entry for the purpose of serving his drive through and/or Stop & Go penalty when the FCY procedure was deployed, he may not serve the penalty until the race has been resumed.
14.5.6 Lap count under the FCY
The number of times the driver crosses the Line during the FCY procedure will be added to the maximum number of times he may cross the Line on the track.