originally printed in SARSCENE.
Discarded ELT triggers search - a first-hand account
by Jack Onisimchuk
On April 20, 2004 Industry Canada was called to track down and
deactivate an emergency locator transmitter (ELT). At 15:45, the
Edmonton District Office of Industry Canada was contacted by the Joint
Rescue Co-ordination Centre (JRCC), Trenton. The
COSPAS-SARSAT satellite the JRCC monitors had detected a signal on
the international emergency frequency of 121.5 MHz, and they were giving
us the heads-up that our help might be required.
The JRCC quickly deployed a
Hercules aircraft to sweep the area in an attempt to locate the
source from the air. Nothing unusual was spotted, and it was decided
that a ground search should be initiated. At 16:10 Industry Canada's
assistance was formally requested. The responsibility to find and
silence the beacon had now been handed to our department.
While not a routine occurrence, many of our Spectrum Management
Officers have been called upon in the past by the JRCC for similar
duties. Our staff is trained, equipped and experienced in tracking down
Since the air search had not spotted a likely source (such as a
downed aircraft) we felt we were dealing with an ELT that had been
inadvertently activated. And while relieved to know that it was unlikely
the result of a plane crash, we still had to act swiftly to find and
deactivate the source. The possibility existed that the false alert
could interfere with a genuine distress signal should an actual
emergency occur in the same area.
With the approximate location of the beacon loaded into our vehicular
mapping/GPS system, and with the aid of our direction-finding equipment,
we began our ground search. Within a half kilometre of the geographical
coordinates JRCC supplied to us, our direction finder locked onto a
signal and began providing bearings towards its origin. By 17:30 we had
arrived at the entrance to the property where we believed the signal
Almost nine out of
every 10 ELT
distress signals prove to be
In the past we have found ELTs in diverse locations from aircraft and
aircraft hangars, to maintenance shops and private homes. However we now
found ourselves at the entrance to a large landfill site. Presented with
acres of refuse, we realized this investigation had the potential to
become an extremely difficult and time consuming process.
With limited vehicular access, our Officer was soon on foot -
switching to a handheld device for its portability. That allowed her to
narrow down the signal to a large pile of garbage that had been hauled
in that day. What followed could best be described as a team effort
between our department, and the on-site workers. While we analysed our
equipment readings and relayed the results to the workers, they began to
sort through the rubble with their back-hoe.
By carefully moving aside the debris one bucket at a time, we were
finally able to zero in on the culprit. It was a small discarded ELT
that could easily fit in the palm of the hand. Once located, the unit
was opened, the batteries disconnected, and the transmitter silenced. It
was now 19:05, less than 3 hours since our vehicle began its patrol.
other than having a broken switch, was fully functional. As ELTs, by
design, activate when jarred we speculated it may have been triggered by
the heavy equipment used at the landfill site. However, the only thing
we can be certain of is that it had not been properly disposed of. The
ELT had been discarded still connected to its antenna and a live battery
pack, and obviously quite capable of triggering a satellite-borne
receiver while buried in trash.
While this exercise does highlight the effectiveness of the emergency
beacon locator network that is currently in place, its use comes at a
significant cost. Almost nine out of every 10 ELT distress signals prove
to be falsely triggered and this has created a tremendous burden on the
resources of all agencies involved. Yet with some due diligence on
behalf of the users, most if not all of these false alarms could be
Some common causes of inadvertent ELT operation are improper storage
or disposal where, as occurred in this instance, the unit was not
properly deactivated. On board aircraft we have seen units that have
been tripped by a hard landing or even severe air turbulence. As well,
inadequate equipment maintenance procedures could contribute to false
activation. When in doubt regarding the use, storage, maintenance or
disposal of ELTs, the manufacturer's recommendations should be followed.
It is our hope that the information presented in this article will
help reduce the waste and potential safety issues that are associated
with false distress signals.
Jack Onisimchuk is a Spectrum Management Officer with the Spectrum
Management, Information Technologies and Telecommunications sector of
Industry Canada, located in the Prairies and Northern Region - based out