[Swordmaker]

Problem One: Gliders are not radar negative. They can be swept and pinged just as easily as any other aircraft.

I would expect them not to carry a transponder though.

[dc-zoo]

They probably found that out when they got blown out of the sky.

[FairOpinion]

But couldn't gliders fly under the radar, at low altitudes?

And if they aren't expecting gliders, they could think it's a large bird?

[Southack]

"Problem One: Gliders are not radar negative. They can be swept and pinged just as easily as any other aircraft."

That's somewhat true for modern metal gliders...but back in WW2 we used all wood gliders to send spies into occupied France.

Wood has a *very*, very small radar cross-section (i.e., it's pretty much invisible).

Of course, your pilot in such a glider would need to be wearing no metal on his/her clothes and have no metal fillings in his teeth and use no metal to wire or detonate the explosives on board if decent stealth was really desired...ditto for using glue instead of rivets (or carbon fibre) to hold the wood frame and cloth fabric glider together (and it couldn't have any electronics or even analog gauges whatsoever, either).

That being said, mere civilians *can* make a stealth glider if properly motivated and informed.

It just won't be a modern metal glider.