For immediate release: April 21, 2003

U.S. Air Force to Deploy Terminal Instrument Procedures System Developed by MDA

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA) announced today that the United States Air Force has exercised an option to acquire 50 Terminal Instrument Procedure licenses for a system designed and developed by MDA Information Systems.

First announced in May 2001, and expanded with additional ‘taskings’ in October 2002, the USAF Terminal Instrument Procedures program (officially known as AFTERPS-R) has become a $5.6 million (CDN) development program at MDA. The licenses exercised today are valued at an additional $2.5 million (CDN).

The Terminal Instrument Procedure system is used to create a virtual flight path for pilots, helping procedure design specialists ensure that all aircraft remain safely clear of obstacles and obstructions, no matter what type of approach they are flying.

“This is a major development for our Information Systems team”, said MDA President and CEO Dan Friedmann, “and a good example of our ongoing, positive working relationship with the United States Air Force. We've worked for almost two years with our American colleagues to make today's announcement possible.”

The U.S. Air Force has now decided to deploy the system at Air Mobility Command, with the potential to expand to all other Major Commands and Units within the USAF in the future. As well, it has the potential to improve the safety of air transportation for other air forces and civil aviation authorities around the world.

Related Websites:
www.mdacorporation.com
www.af.mil



For more information, please contact:

Ted Schellenberg
Media Relations
MacDonald Dettwiler
Telephone: (604) 231-2215
E-mail: teds@mda.ca