Is kml altitude mode "absolute" equivalent to altitude over WGS84 ellipsoid?

Question

I am working with an aviation software which outputs points with altitudes over WGS84 ellipsoid.

Now I want to represent those points in Google Earth, writing a kml file. I know I have to convert the altitudes from ft to m.

Do I have to do any other conversion besides that, or is it "absolute" equivalent to altitude over WGS84?

Documentation is not clear enough for me:

The absolute altitude mode measures altitude relative to sea level, regardless of the actual elevation of the terrain beneath the feature. In this way, features can be placed underground, and will not be visible. Portions of a feature can extend underground, as in the example below. Negative values are accepted, to place features below sea level.

This altitude mode is useful in situations where the altitude value is known precisely. GPS tracks, for example, can use the absolute altitude mode to display paths created while flying or diving.

Answer 1

I recommend you to read this article.

An extract:

Height can be measured in two ways. The GPS uses height (h) above the reference ellipsoid that approximates the earth's surface. The traditional, orthometric height (H) is the height above an imaginary surface called the geoid, which is determined by the earth's gravity and approximated by MSL.

MSL: mean sea level.

So, you need to convert ellipsoid height to orthometric height