A gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum. Mechanically, a gyroscope is a spinning wheel or disc in which the axle is free to assume any orientation. The device's orientation remains nearly fixed, regardless of the mounting platform's motion, because mounting the device in a gimbal minimizes external torque.
Applications of gyroscopes include inertial navigation systems where magnetic compasses would not work (as in the Hubble telescope) or would not be precise enough (as in ICBMs), or for the stabilization of flying vehicles like radio-controlled helicopters or unmanned aerial vehicles.
Stabilizers using gyroscopic flywheels can be found aboard helicopters and large sea-going vessels.
— In-Game Description
The Gyro Stabilizer is a Vehicle Specialization in Battlefield 4 available for helicopters and jets. It reduces the stability penalty from Mobility Hits, allowing the jet not to dive or roll sporadically, and allowing the pilot to stay in the air without crashing at lower altitudes.
— In-game description
The Gyro Stabilizer is a vehicle specialization featured in Battlefield Hardline for helicopters. It functions in a similar manner to that of its Battlefield 4 counterpart, reducing the stability penalty when the vehicle becomes disabled, allowing the helicopter not to dive or roll sporadically.