It can be said that 406 MHz ELT technology evolved too late to be the huge seller that industry leaders predicted. While 406 ELT systems were stuck in a lengthy certification process, satellite tracking systems emerged from the transportation industry and into aviation applications.

New Zealand-based Spidertracks was an early player with the Spider S3 (there’s also the competing Spot line of products that we’ll look at in another article). The new $1795 Spider S5 sends and receives SMS messages through a smartphone. It also interfaces with Lockheed Martin’s surveillance-enhanced search and rescue (SE-SAR) system.