kmacka
Member
I was wondering what an ELT would sound like if it had been activated on 121.5. I heard some noise on 121.5 and was just wondering.
What an ELT sounds like...
- Thread starter kmacka
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kmacka
Member
I heard the noise once again just now. It sort of sounds like a high pitched whistle, it only lasted about 15 seconds now. I have picked it up on 2 diff. scanners.
kicktd
Member
Here is what it sounds like: http://www.grc.nasa.gov/WWW/MAEL/ag/elt.wav kind of like a siren sounding tone that would be hard to mistake.
Also note that people are allowed to test them for 5 minutes on the hour every hour.
Also note that people are allowed to test them for 5 minutes on the hour every hour.
N4JNW
Member
I didn't visit the link, but when I worked at an airport for a summer, we tested one in a Cessna and it made a high pitched warbling sound..
kicktd
Member
Yeah thats what it is. A high pitch warble that kinda sounds like a siren. A lot easier to identify that it's an emergency distress beacon that way, other wise it could be mistaken for interference.
kmacka
Member
Ok that wasnt the sound I heard...that sound is pretty unmistakeable. But one other thing, how far is the range on an ELT. Like how far would someone be able to hear one going off, square miles?
you need to call the authorities... even if the sound doesn't match the recordings.. If you heard it on 121.5 thats cause for concern.. That frequency is designated to emergency transitions only and you should not be hearing ANYTHING, let alone a high pitched tone...
It may be nothing, but it may also be someone in real trouble...
What area are you in?
It may be nothing, but it may also be someone in real trouble...
What area are you in?
kicktd said:
Most ELT's sound just like the link he posted... Although there are some that sound different and some you will never hear at all...
If your radio has a signal meter you can still pick up the signal. Watch the needle/display for burst at a rather quick regular interval.
If you have any other ?'s regarding ELTs just PM me...
I have been searching, locating, and turning them off since I was 14... I'm 30 now... It falls under one of Civil Air Patrol's Missions.
I just noticed your location is in NE Pen.. Your claim actually makes sence because about a week back another guy from your area reported tones on 121.5 as well...
check out http://www.radioreference.com/forums/showthread.php?t=57715
This was only a few days ago..
check out http://www.radioreference.com/forums/showthread.php?t=57715
This was only a few days ago..
ryangassxx said:
Great link for ELT Sounds...!
if your hearing it on 121.5, tune to 243.0 as well...
243.0 is primarilly for Military aircraft...
although there are still many civilian aircraft out there that signal on both frequencies simultaniously...
If your hearing it in NE PA, Willow Grove occasionally has some aircraft going off...
N4JNW
Member
kmacka said:
Range on an ELT would probably be 20 or 25 miles, depending on terrain. If the downed aircraft was in the sea, or lake or body of water, range would be greater, but if it went down in a forest, vice versa.
It is to my understanding, ELT's, also have some sort of a satellite beacon, that goes up and when a satellite recieves it, it will alert the proper parties for the search mission. This is how downed aircraft can be found in jungles and such.
Of course, by filing a flight plan before take-off, rescue times can be cut to a minimum in the event of a accident.
In a quick explanation:
SARSAT is Search and Rescue Satillite. Last I remember there was at least 12 orbiting earth searching for ELT signals.
Only after a SARSAT Satillite passes over a location 3 times with a positive signal does the AFRCC (Air Force Rescue Coordination Center) take actions to search for the device... This eliminates the occasional testing or the similar.
121.5 Civilian
243.0 Military
Some devices can transmit on both freqs.
406.0 is the newest evolution, this one actually send a data burst along with the audio, in incorporates a GPS location code, helping recuers find the device quicker.
AFRCC dispatches the most local appropriate units to find and turn the devices off.
When the satillites get "hits" for 121.5 and 243.0, there is a 30 mile radius from the Lat/Long that the device could fall in... multiply that by the 3 passes it made to become alert status... 3 different Lat/Longs... Your search grid can get pretty big!
The thing to look for is airports in your search grid. 90+ percent of all ELT activations happen when the aircraft is on the ground. (Battery getting low, Hard Landing... More then 3G's of force)
SARSAT is Search and Rescue Satillite. Last I remember there was at least 12 orbiting earth searching for ELT signals.
Only after a SARSAT Satillite passes over a location 3 times with a positive signal does the AFRCC (Air Force Rescue Coordination Center) take actions to search for the device... This eliminates the occasional testing or the similar.
121.5 Civilian
243.0 Military
Some devices can transmit on both freqs.
406.0 is the newest evolution, this one actually send a data burst along with the audio, in incorporates a GPS location code, helping recuers find the device quicker.
AFRCC dispatches the most local appropriate units to find and turn the devices off.
When the satillites get "hits" for 121.5 and 243.0, there is a 30 mile radius from the Lat/Long that the device could fall in... multiply that by the 3 passes it made to become alert status... 3 different Lat/Longs... Your search grid can get pretty big!
The thing to look for is airports in your search grid. 90+ percent of all ELT activations happen when the aircraft is on the ground. (Battery getting low, Hard Landing... More then 3G's of force)
kmacka
Member
ryangassxx said:
After listening to the various tone links that were posted I'm 99% sure what I heard was not an ELT. I know someone from my area posted on this forum last week about something being heard, I did tune into the freq and couldnt hear anything. The reason I first posted was because my squelch was set a little high and it broke silence. It hasnt done that before. So I then took out my pro 97 and went to a high hill approximately 10 miles out of KAVP. I'm pretty much 1/2 way between the Lake Henry Vortac and KAVP. I still heard the noise. It was like a high pitch humming embeded in regular noise. I havent heard it since my second post.
The satellite locating info is interesting, but, once a hit is made it shouldn't be hard to triangulate.
bwhite said:
yes but with an approx. 30 mile radias from each hit... your area could be huge...
Essentially, with the proper equipment, you take strength reading from several locations and take several Compass Asthmiths... from that you can triagulate it on a topo or even a ADC road map...
kicktd
Member
I was in CAP for about a year or so a long time ago. Learned a lot about aircraft and SARs. Wish I would have stayed in longer but had to go to college 
kmacka
Member
vtlo910 said:
Yes I don't believe that had anything to do with it. As I stated I took my pro 97 and went up to a high hill and and still heard the noise, so i dont know what to think. But whatever it was I haven't heard it since, and I have had my scanner on all day.
trainman111
Member
ryangassxx said:
This isn't always true. Often, I will hear aircraft comms. on this frequency. I've never heard an ELT before but I do hear a lot of voice communication. It's usually by mistake but nevertheless. Also, I've heard from other people that when military aircraft intercept a civilian aircraft during a Combat Air Patrol, they communicate with each other on 121.5. Whether or not their supposed to, they do anyway.
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