Whirlybirds S01E29 - Cycle of Terror

A lone gunman is going around town taking potshots at people from his motorcycle. Chuck and P.T.'s secretary, Helen, is out for a motorcycle ride with her boyfriend when they are forced off the road by two hoodlums, who then harass the couple with knives. Luckily, Chuck and P.T. spot the assault from the air and land to help. The assault is thwarted, but as the helicopter lifts off to get back to business, a sniper's bullet hits the 47, damaging the throttle control.