Connexion by Boeing (CBB) was an in-flight online internet connectivity service from Boeing. This service allowed travellers to access a high-speed internet connection while on board a plane in flight through a wired Ethernet or a wireless 802.11 Wi-Fi connection. Connexion by Boeing was formed as a separate business unit of The Boeing Company. Major development on the service commenced with a partnership agreement between United Airlines, Delta Air Lines, and American Airlines on June 13, 2001. Lufthansa joined the partnership as the International launch customer on June 17, 2001. United, Delta, and American subsequently withdrew from the partnership after the 9/11 terrorist attacks due to the severe drop in airline travel that occurred after the attacks.