Plasma it is.
In Eric Lerner's book you will find false V2 radar returns are
now considered radio returns from meteorites.
Trails made plasma active by some means.
If indeed in theory a Tesla craft made the trail augmented
by making a chemical trail, a highly radar reflective trail
might be generated.
To get more than electron beams out of a craft enveloped in electrons
might mean expelling a highly metallic smoke for a trail.
Again, with Tesla craft theory, no trail is made so to make flights
look like a jet means making a chemical trail.
'The Big Bang Never Happened' by Eric J. Lerner (the plasma universe)
FILAMENTS OF THE UNIVERSE
No mention of momentum in those but in:
Physics Before and After Einstein
By Marco Mamone Capria
Search Electromagnetic Momentum Thomson 1893
for history and background of momentum in the ether.
The equations I have indicated before but are stated in the
text. However the text does not go far enough because only Tesla
achieved the expected ether momentum reaction.
Momentum and tubes of force in beginning of Lyne interview:
Date / Time: 9/5/2008 12:00 PM
The UFO Town Meeting!
ET and Tesla craft and historical UFO origins.