Plasma- and acoustic systems can hover large objects above the layer.

The Artist's impression of the UFO is levitating on the beam. (Pinterest)

The laser engine.

One version of the quantum rocket engine is the so-called laser engine. In this engine, the craft is hovering over the extremely hot ion pillar. That pillar can form by using the laser ray. The energy of the laser ray itself cannot carry the craft, but the plasma pillar inside that thing has enough force to make the plasma-levitation system possible. 

Maybe this kind of engine is one of the reasons why some people have seen UFOs:s hovering above the light ray. The laser ray would ionize the air, and the craft will hover above that pillar silently. But if some person walks in that plasma pillar, the effect will be devastating. 

The plasma must be extremely hot that it can rise the craft over the ground. And that makes it dangerous. The same system can be used as the surgical strikes. And this means that this type of engine is also useful for the weapon role. The same systems, that can use as the quantum plasma levitation systems can use as weapons. 

Acoustic tractor beams

Another way to levitate the objects is the soundwaves. In that case, the soundwave-based levitation can of course rise the aircraft from the ground. The oscillating membrane can use to make the pressure waves. Today those systems are still quite primitive, but technology advances. Nothing denies making the acoustic what can rise even cars. 

The system requires high-power loudspeakers. That can rise even the large objects from the ground.  An acoustic tractor beam can be used to levitate the microchips above the layer, or it can use to move those microchips between the work objects. 

The acoustic levitation devices can also take the small-size robot in the middle of it, and that robot can use to install and connect the wires between the small-size components. The system can locate its position with extremely high accuracy. That thing denies that the extremely small and sensitive electronic components are touching the ground and lose their program code. 

Acoustic tractor beams can use as acoustic stun weapons themselves. 

But the acoustic tractor beam can have the use also in the world of military technology. The system can be used to focus the bullet in the middle of the gun barrel, which allows to load it with the electric load. 

That system allows loading very high voltage electricity to the small piece of material. That piece is acting as the capacitor And if it is hovering in the middle of the tubes. That denies the eruption of the electric load.

The water can use as a capacitor. And that thing allows creating deadly electric stun gun, that launches electrically loaded water drops to the target. When that capacitor is launched to the target that projectile is traveling without touching the weapon's core. 

That allows rising the electricity to a higher level than in regular stun weapons. There is the possibility that the "power field" is made by using the hovering iron dust, where is loaded the extremely high electric voltage. When some object is touching those iron bites, it will get a high-power electric shock. This kind of system can use to destroy or damage the combat robots. 

()https://www.sciencealert.com/scientists-have-developed-a-new-way-to-levitate-objects-with-sound