Revised TSO adds class-C TAWS

Technical standard orders for terrain awareness and warning systems (TAWS) have been revised as TSO C151b, which includes a new class-C category intended for voluntary installations on smaller aircraft not covered by the requirements for class-A and -B TAWS. In March 2005 class-A and -B TAWS are required in turbine aircraft with six or more passenger seats, with class-A systems intended for larger Part 91 airplanes and commercial aircraft. Current TAWS manufacturers include ACSS, Goodrich, Honeywell, Sandel Avionics and Universal Avionics. Garmin plans to introduce a TAWS before year-end.