Although the FAA does not specifically require 406-MHz emergency locator transmitters (ELTs) for U.S.-registered aircraft, it seems inevitable that owners and operators will eventually adopt the latest technology. While it remains legal to install and retain 121.5-MHz ELTs that meet technical standard order (TSO) C91a, the newer 406-MHz TSO-C126 ELTs offer much better protection, with GPS-derived position reporting that makes finding a crashed aircraft much easier.
One question that the 406-MHz ELTs raise is what kind of testing protocol they will require. FAR 91.207(d) mandates annual testing of ELTs. Sophisticated ELT test units are available, but these cost thousands of dollars. Fortunately, the improved technology of 406-MHz ELTs has had a beneficial result: a built-in test feature that meets the requirements of 91.207(d) without the need for a test rig. According to Scott Roth, business development manager at Cobham Avionics Communications, the self-test on Cobham ELTs meets all the FAA requirements.
Cobham’s Artex Products division manufactures 406-MHz ELTs that range from a complete kit for $998 for light aircraft to the commercial series for everything up to a Boeing 747, ranging in price from $3,000 to $4,500. Artex recommends that operators conduct the self-test every one to two months.
The ACK Technologies 406-MHz E-04 ELT also offers a self-test function, according to a spokesman. “This should meet the [FAA] requirements.” ACK’s maintenance manual requires that the self-test be done every three months. The ACK E-04 sells for less than $600.