Hamilton topped qualifying at Interlagos on Friday afternoon, beating title rival Max Verstappen by four tenths of a second at the end of Q3.
But FIA technical delegate Jo Bauer found in his post-session checks that the DRS (drag reduction system) on Hamilton’s Mercedes W12 car did not comply with the rules.
The gap between the two rear wing aircraft when DRS is open should not exceed 85 mm according to the FIA’s technical regulations, but the DRS on Hamilton’s Mercedes was found to exceed that limit.
That put Hamilton at risk of being excluded from qualifying, with Mercedes being summoned for questioning beginning at 7:15 p.m.
A long wait followed before the confirmation arrived just before the 22nd in Sao Paulo that there would be no decision on Friday night.
An FIA spokesman confirmed that the hearing had been postponed by the stewards “while they await further evidence which will not be available until the morning”.
This was followed by a bulletin from the stewards asking Bauer to “check the removal of the rear wing assembly of Auto 44, and confiscate this part under seal.”
It added: “Furthermore, the Technical Delegate must oversee the transition from Car 44 to overnight conditions, allowing only those actions necessary to store the car.”
Pole Lewis Hamilton, Mercedes, is interviewed at Parc Ferme
Photo by: Steve Etherington / Motorsport Images
A video appeared on social media showing the DRS test performed on Hamilton’s rear wing while officials check whether the flap opens beyond the allowed 85mm margin.
A fan video of the viewers also appeared to show Hamilton’s title rival, Max Verstappen, watching and briefly touching Hamilton’s back wing after parking his car at the end of qualifying.
The FIA confirmed during the wait that an examination was completed on the rest of the field and found no other breaches of rule, amid a plot by fans about Verstappen’s back wing during qualifying.
If the stewards chose to exclude Hamilton’s car from qualifying, he would start Saturday’s sprint race from the back of the field.