For those of you who don't read manuals...
I really suggest to download & READ the latest manual.
http://3drobotics.com/wp-content/uploads/2015/08/v5_08_21_15.pdf
If you experience a problem in flight, use one of the following emergency procedures to stop Solo, end your flight, or shut off the motors.
3.9.1
Pause
The controller’s Pause button allows you to stop Solo mid-air. Solo will hover at the paused location until given another command. Use the Pause button to stop Solo from hitting an obstacle or to re-orient Solo for navigation. Press Pause during Return Home or Land to pause Solo and stop the landing. Pause is available only with GPS lock.
3.9.2
Regain Manual Control
Keep the controller easily accessible at all times during flight, including during Smart Shots, and be prepared to regain manual control at any time. To return to standard flight during Smart Shots, Return Home, or Land, press the Fly button.
3.9.3
Return Home
If Solo acquired GPS lock prior to takeoff, press the controller’s Home button to return Solo to the launch point and land. Use return home after receiving a low battery notification or to end your flight easily. Solo will not avoid obstacles while returning home; always verify that the return path is clear before activating Return Home.
3.9.4
Land
To land Solo at its current position, press and hold the Fly button. Lift the throttle at any time to exit the landing procedure. If Solo does not have GPS lock, there will be no automatic positioning as Solo descends, and drifting may occur depending on environmental conditions.
3.9.5
Motor Shutoff
In the event that Solo’s motors do not stop after landing or for an emergency in-flight kill switch, Solo includes an emergency motor shutoff procedure. To shut off the motors at any time, either in flight or on the ground, hold the A, B, and Pause buttons at the same time. An initial screen will appear on the controller to confirm the shutoff command; continue to hold A, B, and Pause buttons to activate motor shutoff. Use the emergency motor shutoff only as a last resort.

I really suggest to download & READ the latest manual.
http://3drobotics.com/wp-content/uploads/2015/08/v5_08_21_15.pdf
If you experience a problem in flight, use one of the following emergency procedures to stop Solo, end your flight, or shut off the motors.
3.9.1
Pause
The controller’s Pause button allows you to stop Solo mid-air. Solo will hover at the paused location until given another command. Use the Pause button to stop Solo from hitting an obstacle or to re-orient Solo for navigation. Press Pause during Return Home or Land to pause Solo and stop the landing. Pause is available only with GPS lock.
3.9.2
Regain Manual Control
Keep the controller easily accessible at all times during flight, including during Smart Shots, and be prepared to regain manual control at any time. To return to standard flight during Smart Shots, Return Home, or Land, press the Fly button.
3.9.3
Return Home
If Solo acquired GPS lock prior to takeoff, press the controller’s Home button to return Solo to the launch point and land. Use return home after receiving a low battery notification or to end your flight easily. Solo will not avoid obstacles while returning home; always verify that the return path is clear before activating Return Home.
3.9.4
Land
To land Solo at its current position, press and hold the Fly button. Lift the throttle at any time to exit the landing procedure. If Solo does not have GPS lock, there will be no automatic positioning as Solo descends, and drifting may occur depending on environmental conditions.
3.9.5
Motor Shutoff
In the event that Solo’s motors do not stop after landing or for an emergency in-flight kill switch, Solo includes an emergency motor shutoff procedure. To shut off the motors at any time, either in flight or on the ground, hold the A, B, and Pause buttons at the same time. An initial screen will appear on the controller to confirm the shutoff command; continue to hold A, B, and Pause buttons to activate motor shutoff. Use the emergency motor shutoff only as a last resort.
