This information makes good sense for a being so obviously associated with air as to be called an aerial servant. However, the description of these same beings which accompanies the clerical spell Aerial Servant indicates they hail from the Ethereal Plane:Aerial servants are beings native to the Elemental Plane of Air. They are only encountered on the Prime Plane when conjured by a cleric. On their home plane, they are known by a name which sounds like "haoou." [O]n their home Plane, the haoou have their own evil empire, which reigns in places where there are few or no other creatures. Their enemies are the helions and the djinn. They fear earth-type creatures and attacks.
Note that this spell is explicitly stated to have no effect on the Plane of Air, but functions normally elsewhere.An aerial servant is a very intelligent humanoid being from the Ethereal Plane. With this spell, the cleric summons one of these beings, which appears immediately.... It can become ethereal at will, and thus can travel to most places easily. However, it cannot pass a protection from evil spell effect. If it cannot perform its duty within the duration of the spell, the servant becomes insane and returns to attack the caster.
How to reconcile these inconsistencies which all occur within the Companion Rules? I think the intent was for the haoou to be from the Elemental Plane of Air, but I like the idea of it's being able to become ethereal and have some connection to the Ethereal Plane. Perhaps something about the spell always causes the summoned servant to travel from the Plane of Air via the Ethereal Plane, hence the connection and associated powers. This can be so whether the servant is summoned to the Prime Plane, another elemental plane, the Astral Plane, or an Outer Plane. If it is summoned to the Ethereal Plane itself, well, the whole business becomes irrelevant anyway.
Anyone else have thoughts about the topic? Has anyone decided the haoou actually do originate in the Ethereal Plane instead of the Plane of Air?