How to hide an airplane factory during wartime

Lockheed company is manufacturing F - 22 Raptor which is said to be the strongest fighter at present. It seems that during the Second World War, I hid it covering the Burbank plant in California with a net.

Details are as follows.

Before:
First, when not doing anything. From the top you can see that there is a factory.


After:
Next, after hiding the factory. As far as I'm looking at from the top, I do not know that there is a factory here.


Seen from the side, it feels like a set of movies.


But inside is a proper factory.


GoodShit: thanks to Chris J. ... Please open thumbs