I'm pretty sure it's common. My adult jade plant does this. If you take a cutting and stick it in the soil or a cup of water, it'll keep on living. I'm assuming that is the purpose.

Aerial roots are not normal for healthy plants imho. These roots grow if a vascular tissue (xylem) cannot conduct a nutrients due to the fact they are clogged

If it is a cutting I wouldn't necessarily consider it to be healthy as there is no way for it to take up water, so they start sending out these feeler roots to find water wherever they can. It is doing the same thing under the soil. Once the in-ground roots have established themselves the aerial roots will likely dry up and fall off. Or, once you are sure there are in-ground roots you could remove them.

Patrick, I 'm thinking the same, this plant was searching for water. Three weeks ago I noticed a lot of leaves starting to shrivel from lack of water, I started misting once a day and the leaves plumbed right up. I'm assuming I have some root growth below the soil at about the same rate as the aerial roots.

rina, the stem is 8" in length, about 3/4 inch in diameter. It surely has new roots, I'm seeing signs of new growth this morning.

I had a couple of large cuttings of jade and all of them dropped leaves, the plant is using the water that are stored in the older leaves to support new growth and provide energy for root growth. No need to worry.