Ten fire engines and around 70 firefighters tackled a grass fire on Haydock Avenue in Northolt.
Fifty-five 999 calls has been taken to this visible blaze.
Station Manager James Ryan, who was at the scene said:
"We believe the fire started in trees behind a row of terrace house and spread to open grass land. Firefighters are worked hard to stop the fire from spreading to nearby houses."
The Brigade was called at 1552 and the fire was under control by 1828. Fire crews from Wembley, Harrow, Ruislip, Southall and surrounding fire stations were at the scene. The cause of the fire is under investigation.