The SB2283MG is an ultra high speed servo running at .048sec transit @ 7.4V. This servo is a great choice for your heli gyro. 

Features:
Combines leading edge technology with super high 12 bit (4096) resolution and titanium gears.
Super light-weight.
Brushless motor provides longer life and cooler operating temps.
The aluminum case design not only looks good but also allows for cooler and smoother operating temps.
Our servos are totally green - from materials to production, these servos are environmentally friendly.
Intended for use in heli rudder applications only.

Dimensions(mm)    40.3 x 20.2 x 38.7
Weight(g):    69.0
Speed @6.0V:    .06sec
Torque@6.0V:    69.4 oz-in
Speed @ 7.4V:    .048sec
Torque @ 7.4V:    138.9 oz-in.
Gear Type:    Metal
Bearings:    2 BB
Frequency:    250-333Hz
Pulse Width Frequency:    1520>