With that background, what does FAA use today? If they do not use
'skin paint' why can't the 'glass' birds with a wooden prop, turn off
their transponder and fly through all the restricted areas unseen?

I live in a Class D airspace. I wanted to see my house a bit closer
than 2600 ft, so I got on the handheld and asked for permission to
come down below pattern altitude. Duly granted. Then it transpired
that the controller couldn't see me. I told him my location, altitude,
and that I was circling. He told me to report at 800 feet, which I
did. But he didn't replied, and I'm not sure that he actually saw me
on the radar at any time.

J-3 Cub with metal prop.

all the best -- Dan Ford
email: (put CUB in subject line)

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