A Brazilian judge has banned three types of jets from Sao Paulo's Congonhas airport because of concerns about the length of the runway.
Fokker 100s - and two types of Boeing - are now banned
Judge Ronald Carvalho Filho ruled Fokker 100 jets and two types of Boeing 737 were too large to be accommodated.
There have also been problems reported with the airport's drainage system.
The ruling follows months of disruption in Brazil's aviation sector, including work-to-rule stoppages by air-traffic control staff.
Authorities at Congonhas airport are expected to appeal against the decision.
From Thursday, Fokker 100s, Boeing 737-800s and Boeing 737-700s will not be able to use the airport, news agency AP reported.
The judge said the main runway at the airport needed to be 388 meters (1,275 feet) longer for these types of aircraft to use it.
Federal prosecutors had argued both the length of the runway and poor drainage were risks, the agency reported.
It said that in recent months excess water on the runway had led to some planes skidding off the runway.
"The safety conditions of the runway and the airport as a whole are adequate," a spokeswoman from Brazil's National Agency of Civil Aviation said.
She added the judge's ruling could end up affecting 10,000 passengers per day.
"If the injunction stands, it will cause total chaos," a spokesman for Tam Linhas Aereas, SA, the nation's biggest carrier, said.
On Tuesday morning heavy rains caused the airport to be closed for an hour.