Why you need this? Imagine this situation: you come upon an interesting parcel on some region, there are few prims rezzed at ground level or non at all, but the parcel info says there are a lot more prims rezzed somewhere in the parcel, even in some cases to the point that there are few prims left.
Usually, that means there are things rezzed up in the sky and your curiosity wants to find them as quickly and easily as possible. The "area search" feature that comes with most viewers is not useful to find those prims because it cannot filter or identify prims by the parcel they are rezzed into.
Another non-ideal option is to max your draw distance and manouver your camera to look straight up into the parcel's air space. That way you will see most things rezzed up there but you won't have a clue how high or big they are until getting there or if they are really within this parcel's limits or in neighboring parcels. Besides you will surely fail to see small or transparent prims. If the object is big enough to be viewable from ground level and is not too far away up you can teleport there by double clicking on it, else you will have to fly up for a while for the viewer to let you select that object and teleport to it.
There is at least one scanner in the marketplace that promise to be able to filter objects by parcel, but appart from its high price of L$ 500, it does not say if it lets you look for "any" object in a parcel or just for specific ones, like those owned by someone or with a certain string in their name.
Now, with this flying vehicule you can change its shape to match the size and perimeter of any parcel, get on board and fly straight up until it is stopped the moment it bumps against something rezzed somewhere within the parcel's air space. While flying up you don't have to keep looking around with an eagle eye to spot the smallest prim. No matter how small an object is, even if it is transparent, this ship will be stopped when it bumps against it, at least it is set to be a phantom prim of course.
If the parcel is too big to cover with the shape of the bumper sized to the maximum possible, divide the parcel in areas to be scanned (temporarily rezzing reference prims in the ground) and custome the shape of your bumper to the size and shape of the section of parcel to be scanned.
The limit on the size of the sky bumper surface area is set by the limit on megaprim size (64 meters) and the linkability of megaprims. Usually you will be able to resize the sky bumper to a rectangle at least 64 meters wide x +64 meters long, or even replace square prims with triangles if matching the parcel's shape requires that. Just remember to keep a backup copy of your sky bumper in its default shape and size.
While flying up, you can use the first person "mouselook view" to look around or straitght up. Included with your purchase is a Flight Feather HUD which allows you to display altitude and speed info while using this view.
Just remember, before touching anything rezzed up there you have to stand up on the vehicule, else the bumper will loose the alignment with the parcel boundaries. You may forget to stand up and for this reason I suggest to copy the location and rotation values of the bumper before lift off so you can restore or check them easily.
PS
Most people trying to bump on things while flying up think first about wearing a supersize cube attachment but this does not work because this cube, being prim, sculpted or mesh, lacks the physics required to bump with something. It passes through other objects like a phantom prim, while only your avatar shape, which covers a small area, remains "bumpable".
