Charlie Tango is the name of the helicopter that Christian Grey owns and pilots. It is a Eurocopter. He frequently uses it to travel between Seattle and Portland. After meeting Ana, he brings her to his penthouse in Seattle via Charlie Tango.
In Fifty Shades Darker, Jack Hyde sabotages Charlie Tango's engines. Christian and his business partner Ros were on a business trip and were taking a scenic detour over Mt. Saint Helens when the both engines had an electrical failure. He was able to crash-land without injury to himself or his passenger. Were Christian not a skilled pilot, this kind of failure would have led to a fatal crash.