Simplify the following text for a Grade 10 native English-speaking person.
Original: London Stansted Airport is a passenger airport located at Stansted Mountfitchet in the local government district of Uttlesford in Essex , 48 k northeast of Central London .
Simplified: London Stansted Airport is a large passenger airport located in the Uttlesford District of the English county of Essex about 30 miles ( 48 km ) north-east of London .