An ELT antenna which is submerged by just a couple of cm of water will suffer to much attenuation from the water, to be effective. A fixed gear aircraft is likely to turn over, so the antenna will be in the water and covered by the wings.
I think a PLB and / or Safelink as addition to an ELT would be better for those flying frequently over water.
A non 406 MHz is quite useless, as well as an incorrect coded and / or registered ELT or PLB. It is VERY common for these to be either programmed incorrectly or not registered, which makes them quite useless. I am always amazed people spent money on these safety devices, but doesn’t seem bother to maintain them.
During testing I will frequently find the switched off with customers stating not to drain the battery. Please always leave your ELT in the ARM position.
Manually triggering would be could to do at an emergency. As NCYankee pointed out, it takes 50 seconds for the first 406 MHz burst is transmitted. If the antenna is broken, submerged in water within that time, the transmission is lost.
Been trying to find those for years.
They are out their.
I don’t think the system is perfect, but sure better that nothing.
The PLB should be in your pocket not in the flight bag… or in a quick release clamp next to the door. Most PLBs do have their own GPS. I bought one in FHA last year.
I do know of some cases where planes were found on land by zooming in on elt signals. I also recall reading about sar being triggered by the new 406 sat technology. Actual saves i don’t know.
Last year there was a case where a glider crashed on a mountain here. Elt signal was picked up but with out position. On the end FLARM sihnals were used to find the plane. Unfortunately the Pilot had died in the mean time after initially surviving. Ab PLB would have probably done a better job.
Re mh370 and Asean… naturally elts on tge bottom of the sea do not do much. On mh17 the elt did trigger.
what about all of the “saves” thanks to ELTs and PLBs ?
Been trying to find those for years. Maybe they don’t exist? Complete waste of space IMO…
Everyone always talks about the instances where the ELT didn’t work – what about all of the “saves” thanks to ELTs and PLBs ?
In GA, I fail to understand why PLBs are not accepted as replacement for ELTs. They cost less and lead the rescuers directly to you instead of a wreckage you might have already abandoned.
PLBs do not have inertia switches, so it wan’t activate automatically on impact;
Secondly, imagine you do have a real emergency, are you going to get disstracted and start looking for that damn PLB in your flight bag ?
That said, nobody’s saying you can’t bring a PLB along !
In GA, I fail to understand why PLBs are not accepted as replacement for ELTs.
According to Part-NCO they are, if the aircraft is certified for no more than 6 occupants.
The 406 ELT’s are the least worse as they are digital and if interfaced to a GPS can provide near real time position
How many 406 ELTs in the US are wired to a GPS?
I’m fairly sure that virtually none of the 406 ELTs in SEPs in europe are wired to a GPS.
The sentiment that ELTs are a waste of space is often heard from the USA – all N-reg must have a fixed 121.50 ELT, anywhere in the world.
A fixed ELT is required, but may be 121.5 or 406 MHz. Some are also 243 MHz or all three frequencies. SARSAT no longer monitors the two analog frequencies. The 406 ELT’s are the least worse as they are digital and if interfaced to a GPS can provide near real time position, but even they need about one minute before their first transmission and then repeat each minute after that. There are many issues with activation and in particular they aren’t of much use if the cable from the ELT to the antenna is pulled off or cut in the accident or the antenna is covered by debris. Without a GPS position and early activation by the pilot, a forced landing in water is unlikely to generate a position.
I can see that in a high speed loss of control (-24000fpm reported for Air Asia) an ELT will go down with what’s left of the aircraft, but how many GA planes ditch and the investigators are sufficiently motivated to spend money to retrieve them? I doubt they would retrieve most of them even if there was a floating beacon on the surface with a bit of string going all the way down to the wreckage. Down here, they could not be bothered to pull out N147KA even after amateur divers “accidentally” found the wreckage, which was obviously in shallow water (for amateur scuba).
Personally I am in favour of an ELT, so this is just making the contrary argument…
If I had an engine failure I would manually trigger the ELT.
This ELT question is also interesting in conjunction with MH370 and now the Air Asia desaster. In both cases, the ELTs were obviously not triggered. What can be the reason apart from purposeful de-activation or an (initially) perfect ditching?
In GA, I fail to understand why PLBs are not accepted as replacement for ELTs. They cost less and lead the rescuers directly to you instead of a wreckage you might have already abandoned.
