Unassisted you can fly to an altitude of about 180 meters above ground level, and you can hover at up to about 50 meters above ground level. A flight assist device allows you to fly and hover much higher than that, and allows you to fly faster than you can unassisted.

The Vengeance Flight Assist device provides three capabilities:

High Altitude Hover

With the device enabled you can fly to and hover at any altitude. When you release the flight controls you do not drift downward.

Speed Boost

The Vengeance Flight Assist device provides a speed boost that you can turn on and off independent of the hover capability. It increases your movement speed. You get a larger boost at high altitude than you do at low altitude. You can also vary the amount of boost. When attached to a lower HUD position you get a numeric readout of your current speed.

Momentum Arrest

Normally, assisted or not, you drift quite a bit after you release the flight controls while moving, making precise movement impossible. With Momentum Arrest enabled you will stop moving as soon as you release the flight controls. The trade-off is that the quick stop looks quite unpleasant for the avatar, and not at all graceful. I do not know how to stop the violent twist you get when Momentum Arrest kicks in, so if you find the lack of grace not worth the flying precision it enables, you can turn Momentum Arrest off.

Credits

The idea for Momentum Arrest came from another freely available flight assist script, the source code for which you'll find on the Second Life discussion forum.

The Vengeance Flight Assist script was written by Anya Ristow.