ELT issues

In that time we have gone from having them as an optional item to having their use mandated by the regulator. At one point the regulator wanted to have ELTs only mounted in aircraft, but following a campaign by AOPA it was agreed that an aircraft could have a fixed or a portable unit.

The main requirement was that an aircraft had to have an ELT aboard if flown more than 50nm from home base.

The 121. 5/243 MHz units suffered from electronic equipment interference and, more critically, there were too many accidental false alarms and too many deliberate false alarms.

Over the years there has been more than one trailer boat being towed across Australia with a dislodged ELT creating a moving signal! Then there have been cases where a search aircraft has been homing in onsignal and then that signal has been turned off, the person operating the unit having no regard for the cost of mounting a search or that a search crew was possibly risking their lives by being involved in a search.

The new 406 MHz units narrow down the search area and more importantly they carry a digital signature so that the unit can be traced back to an owner and in so doing markedly reduce the number of false the 121. 5 MHz frequency at startup or shutdown can assist with the early detection of an operating ELT and thus facilitate early assistance to the occupants of a downed aircraft.

While more than adequate advance notice was given regarding the changeover from 121. 5/243 MHz units to 406 MHz units, anecdotally a very large number of aircraft operators and pilots left the acquisition of the new unit until closealarms. That trace can also assist to see if the unit has been activated by accident or for good reason. Some 406 MHz units can transmit the GPS location which in turn effectively pinpoints the crash location. While the 406 MHz transmission is essential for satellite monitoring, a 121. 5 MHz component of the transmission is still necessary to assist with the final homing of an activated beacon.

Indeed, aircraft monitoring to the February 1 start date. The result has been that both fixed installation and portable units have been in short supply. Some aircraft had not had their fixed installation units changed over by early June.

Interestingly, in Canada, their regulator has mandated that aircraft carry an ELT if flown more than 25nm from home base. In the US the FAA is pushing to mandate the carriage of 406 MHzELTs, but the US AOPA is resisting the move on the grounds of cost to the owner or pilot. Given the number of aircraft that go missing in the US each year, one has to wonder about this attitude.

On the technical side it has been noted that in a few Australian accidents the ELT did not operate automatically on impact. It is understood that the FAA is seeking to have better design requirements that will have all fixed unit ELTs work on impact.

For a number of years this writer has been carrying a personal ELT while on any flight beyond 50nm from home base, even if the aircraft has its own ELT fitted. The first unit was a compact 121. 5/243 unit, the current unit is a 406 MHz unit complete with GPS position data transmission capability.

My unit is carried on the pants belt, not in the aircraft glove box, with the idea being that should the aircraft come down and burn or is ditched, and I can exit alive, then I have a reasonable chance of being located in the short term.

This was also the idea behind AOPA wanting the pilot to have a choice between a fixed or portable ELT.

ELTs are a worthy bit of technical kit that can assist the occupants of a downed aircraft.

They may not be perfect but they are the best we have available at this time. To not have one is stacking the odds against a good outcome in the event of the occupants surviving an accident.

In short, adopt the Scouts’ motto and be prepared. Given that frame of mind you may never have to use the ELT. n Contact Dave by email at: flyer02@optusnet. com. au

To not have one is stacking the odds against a good outcome in the event of surviving an accident.