No, its not a real fire on the airliner, neither its a huge prominence. This is an optical illusion caused by the hot fume coming from the airliner's exhaust.
Gear: Nikon D5600, Sigma 150-600c lens
Exif: f/11, ISO 100, 1/500 second, 600mm
Date: 7th January 2021
Location: Kolkata, India