Large triangle ca. 1964

[Carlos]

I was perusing Google books library of Popular Science magazine. The cover of the Dec. 64 issue caught my eye, so I began reading and lo and behold what do I find but a triangle shaped blimp.

[SMiles]

Hey, cool find Carlos!

I've heard of "sky-hook" balloons but never knew some (or all?) were triangular-donut shaped.

[Carlos]

Given the advances made in material technology, many of the large, silent triangle sightings from the 60's on were of neutral buoyancy/lighter-than-air dirigibles operated by the military. Even in today's supposedly crowded skies, such aircraft could hide in plain sight with simple camouflage outside of commercial airspace by simply appearing cloud like by floating in mid air at altitudes not normally used by commercial/private aircraft.