I've seen three low flying craft always at night with head lights, blue and red strobes and white constant wing lights flying a regular route over our area.

The first time I saw it, it was producing a very quiet jet engine sound and was flying so slow I thought it was going to stall.

The second time it flew over my house but seemed to hover making me think it was a helicopter until I opened the skylight window only to hear it fly over without any sound at all. They seem to be designed to look like commercial liners from far away but from my house I can judge their distance and speed.

I don't believe for one instant that these are manned craft. They appear too small, too light and fly too low. They also appear too bright as if they are using some sort of display matrix to produce the wing and fuselage shape. I live in the hills so I get a good view of the surrounding valleys. They seem to navigate by church spires.

I'm pretty sure these are experimental drones - probably DARPA glass fiber models. I can't think why they'd want to fly them over my area especially at 1.30am.