Firefighters are tackling an aircraft hangar blaze at Southend Airport.
Six fire engines attended the fire on Wednesday morning.
A spokesman for Essex County Fire and Rescue Service said the airport is running as usual.
A statement said: "Firefighters are using a aerial ladder platform (ALP) to pour water on the large building from above.
"The officer in charge at the incident reports crews are making good progress."
Pictures shared on social media showed black smoke coming from the large building.
A statement from the airport said: "Essex County Fire and Rescue Service is currently dealing with an incident at the Air Livery hanger on the north side of the airfield.
"London Southend Airport is still open and operating as normal".