You're not imagining it treadigraph. There was a big black hangar type building with "Fairey" on it in big white letters located in an open area off the back road from Hayes to Southall. It was visible from the old British Airways club that was over that way. I believe it was associated with their hydraulics business. Its hard to imagine today, but there was quite a lot of aircraft manufacturing going on down that way until the seventies. Westland built Puma helicopters in Hayes.