Avionics News July 2013 - 39

one based on older, analog technology and another transmitting a
digital signal, which can include GPS-based position information.
As if that isn’t enough, a quarrel over ELTs has broken out between two federal agencies. On one hand, the Federal Communications Commission wants to eliminate approvals for older ELTs
in favor of the newer technology. Its actions have been met with a
storm of protest from aircraft operators and industry. The Federal
Aviation Administration, meanwhile, persists in allowing ELTs
manufactured under the older standards to be used, even though
the international agency tasked with identifying and tracking
ELT signals stopped listening for them more than four years ago.
Even the National Transportation Safety Board has chimed in.
What’s going on with ELTs? What’s required? And
what’s next?

A Checkered History
Whenever the ELT gets discussed, it’s often accepted the
ELT came into being in the aftermath of the Oct. 16, 1972,
disappearance of a Cessna 310 carrying U.S. House of Representatives Majority Leader Hale Boggs (D-La.), Rep. Nick
Begich (D-Alaska), Begich’s aide, Russell Brown, and the pilot, Don Jonz, from Anchorage, Alaska, to Juneau. As of this
writing and despite a massive 39-day search, no trace of the
flight has ever been found.
In fact, the original law mandating ELTs (then called emergency locator beacons) was tacked onto the bill creating the Occupational Safety and Health Administration some two years earlier. That legislation was enacted with President Richard Nixon’s
signature on Dec. 29, 1970, mandating the devices in new, fixedwing aircraft by the end of 1971, and aboard in-service airplanes
by the end of 1973. Its timing – well before the 310 carrying
Boggs and Begich disappeared – was a preemptive response to
laws passed in California and Washington requiring the devices,
and to legislative proposals in other states. Rather than have a
patchwork of possibly conflicting state laws requiring the devices, it’s better to have one federal law, the thinking went.
By early 1973, however, it was clear (even to Congress)
there weren’t enough ELTs available to equip the fleet by
the new deadline. Congress again changed the deadline, to
June 30, 1974, giving owners and operators additional time
to comply. By 1975, however, those same owners and operators were telling Congress ELTs didn’t work. Further,
replacement parts and batteries were scarce, and the FAA
was interpreting Congress’ intent to mean an aircraft without a working ELT wasn’t airworthy. In 1977, Congress
acted again, loosening the statute and allowing aircraft op-

Allowing the FCC to intrude
into even this relatively
small portion of the FAA’s
jurisdiction would be an
extremely poor precedent.
eration when the ELT was removed for “repair, modification or replacement.”
Pilots, owners and operators quickly learned those early, firstgeneration ELTs, produced under the FAA’s Technical Standard
Order-C91, frequently needed repair, modification or replacement. They failed to activate in a crash more than 75 percent of
the time. When they did activate, a whopping 97 percent were
false alarms, according to the Aircraft Owners and Pilots Association, resulting from something like a hard landing. Many of
the false-alarm and activation failures were addressed with improved standards of TSO-C91a, which replaced the earlier TSOC91 and went into effect in 1985.
By 1990, the FAA proposed terminating future installations
of TSO-C91 ELTs, noting their “known unsatisfactory performance.” And in December 1992, the FAA issued TSO-C126,
which embraced the digital 406 megahertz technology, although
compliant ELTs still would transmit on the “legacy” 121.5/243.0
MHz frequencies. At that time, devices approved under any of
the three then-current TSOs could be used to comply with the
FAA’s requirement to carry an ELT. Effective Dec. 19, 1994, the
original TSO-C91 was canceled, and ELTs complying with the
older standard no longer could be manufactured. Beginning June
21, 1995, they couldn’t be installed, either.
But the damage was done. The ELT was universally reviled
throughout the aviation industry as a relatively expensive government-mandated device that simply didn’t work, despite their better performance under TSO-C91a. They required attention during aircraft inspections and, periodically, a new battery. But they
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