Phil Hynes raised the alarm after spotting a house fire from 2,000ft up.
The 35-year-old private pilot was on his way home when he saw flames coming from a building in London Road, West Kingsdown, yesterday afternoon.
There were no emergency crews on the ground, so he radioed air traffic controllers to explain what he had seen.
He said: “You get told when training to report anything unusual on the ground if you can.
“I was coming back from the Isle of Wight and it was a lovely day on my way to Stapleford and I saw this smoke in the distance.
“I thought it was a bit more aggressive than normal and was almost at my level at 2,000ft up straight ahead on my path.
“I diverted a bit to have a look at what was going on and it looked like it was burning quite aggressively.
“From that height you can just about make out buildings for example a block of flats or a church and I couldn’t see any fire engines.
“It was the first time I’ve reported anything like that. I spoke to the controller on the radio and said there seems to be something substantial alight near Brands Hatch.
“When I’d just passed the QEII bridge I heard back saying they’d informed the fire brigade and they were on their way."
Firefighters from Dartford fire station were sent to the scene at about 5pm and found the empty house, one of two on the site, well alight.
In total four fire engines were sent to the scene to tackle the flames with crews spending about four hours there.
It is understood the properties had previously been boarded up and had been derelict for some time.
A spokesman for Kent Fire and Rescue Service said: “One of the houses was totally destroyed by the flames in what was a possible arson attack.”
Essex resident Mr Hynes, who was flying a PA28 Warrior, was on his way back from taking his 70-year-old mum for a birthday treat flight to the Isle of Wight, after a balloon ride got cancelled.