The X-48B first flew on July 20, 2007, reaching an altitude of 7,500 ft (2,286 m); the flight lasting 31 minutes.
 The remotely piloted aircraft was successfully stalled for the first time on September 4, 2008, with fixed leading edge slats, a forward center of gravity, and 23-degree angle of attack (2° beyond the maximum coefficient of lift).
 Stall testing was repeated on September 11 with a NASA pilot at the console.

On March 19, 2010, NASA and Boeing successfully completed the initial flight testing phase of the X-48B. Fay Collier, manager of the ERA Project in NASA's Aeronautics Research Mission Directorate commented on the completion of the first phase of testing saying, "This project is a huge success.
Bottom line: the team has proven the ability to fly tailless aircraft to the edge of the low-speed envelope safely."

Following the installation of a new flight computer in 2010, the X-48B was to continue a new phase of flight tests to investigate controllability aspects.
 The second phase of flight tests with the X-48B began in September 2010.

The X-48C first flew on August 7, 2012.
Engine yaw control was among the aspects to be studied.
 The X-48C completed its 8-month flight test program with its 30th flight on 9 April 2013.
The X-48B first flew on July 20, 2007, reaching an altitude of 7,500 ft (2,286 m); the flight lasting 31 minutes.  The remotely piloted aircraft was successfully stalled for the first time on September 4, 2008, with fixed leading edge slats, a forward center of gravity, and 23-degree angle of attack (2° beyond the maximum coefficient of lift).  Stall testing was repeated on September 11 with a NASA pilot at the console.
On March 19, 2010, NASA and Boeing successfully completed the initial flight testing phase of the X-48B. Fay Collier, manager of the ERA Project in NASA's Aeronautics Research Mission Directorate commented on the completion of the first phase of testing saying, "This project is a huge success. Bottom line: the team has proven the ability to fly tailless aircraft to the edge of the low-speed envelope safely."
Following the installation of a new flight computer in 2010, the X-48B was to continue a new phase of flight tests to investigate controllability aspects.  The second phase of flight tests with the X-48B began in September 2010.
The X-48C first flew on August 7, 2012. Engine yaw control was among the aspects to be studied.  The X-48C completed its 8-month flight test program with its 30th flight on 9 April 2013.
Boeing X-48