Defense Play

Defense Play is a 1988 American action-drama film directed by Monte Markham, and starring David Oliver, Susan Ursitti, Monte Markham, Eric Gilliom, Jamie McMurray, Jack Esformes, and William Frankfather. The film was released by Trans World Entertainment on September 9, 1988.
Plot.
Professor Vandemeer works on a secret project for the US-Air-Force called DART: a very small helicopter for scouting and defense. When he gets killed, Colonel Denton gets under suspicion. His son Scott and Vandemeers daughter Karen believe in his innocence and search for the true murderer and his motives.