SkyTrac Systems has obtained a supplemental type certificate (STC) for the installation of its automated flight following and satellite communications equipment on the de Havilland DHC-6 Twin Otter airframe type. The DHC-6 is a 20 passenger STOL (Short Takeoff and Landing) utility aircraft developed by de Havilland Canada. The aircraft's fixed tricycle undercarriage, STOL abilities and high rate of climb have made it a successful cargo, regional passenger airliner and MEDEVAC aircraft. SkyTrac’s long and growing list of STCs include popular rotary and fixed wing aircraft from Cessna, de Havilland, Robinson, Bell, MBB, Sikorsky, Eurocopter, Beechcraft, Raytheon and Agusta Westland.