What's the slogan on the roof?

A film studio built next to the airport wrote a big sign on the roof to avoid the interference of plane sounds: "Please be quiet!" " "Every letter is eight feet square. As a result, the slogan brought more noise, because all the pilots wanted to see what was written on the roof and competed to fly the plane lower.

Stupid methods will only make things worse. If we don't have a smarter solution, we'd better keep the status quo.