Strange siren sound on 121.350

[SCPD]

Listening to Boston Center ZBW22 121.350 when I started hearing a strange siren like sound that went on for like five min or more. The first thing that came to mind was some sorta distress beacon? Unfortunatly I don't have a line to my computer for a recording. Are there any beacons like this on civil aircraft that sound when a aircraft is in distress?

Thanks
Rob

 

[Colin9690]

Civil aircraft have what's called ELTs, or Emergency location transmitters. They make a siren sound, however they only broadcast the signal on the civilian guard frequency (121.5), and the military guard frequency (243.0).

Here's what it sounds like: Listen To An ELT / EPIRB

 

[wtp]

and....

they can test the transmission on some freqs..i just don't remember which ones

 

[SCPD]

Thanks Colin! The siren sound I got was more drawn out or slower than the examples you provided. Almost like a police car siren. Very low signal just above the static. Could have been someone deliberatly trying to jam the freq.

 

[ASTRO2001]

CAP ELT

I was in the Civil Air Patrol and we had practice ELT with the freq of 121.775- 121.300 we used them for practice in the field all over the state.

 

[Colin9690]

If it was a test, the aircraft would have to be on the ground and pretty close to you as well since you were able to pick it up. The only time ELTs can be tested is on the ground, airborne ELT checks aren't authorized.

 

[navaidstech]

If it was a test, the aircraft would have to be on the ground and pretty close to you as well since you were able to pick it up. The only time ELTs can be tested is on the ground, airborne ELT checks aren't authorized.

But it doesn't mean that they can't be inadvertently tripped off. I was chasing such an ELT a bunch of years ago here in the Toronto area. I was getting reception reports from several control towers located at a considerable distance from Toronto and yet my ELT receiver was pointing towards the lake, in the opposite direction from them. As it turned out, it was a United flight somewhere south of the border that had its ELT tripped off for some reason....strangest, and possibly the last ever ELT trouble call I received to date.

 

[majoco]

I was the avionics tech that lived closest to the airport for a while - I'm sure the ground control ATC bloke had my phone number on his speed dial! Our aircraft had the ELT switch in front of the power levers and if you threw the log book just at the right place the guard lifted up and on went the ELT. Of course the pilots had turned all the power off so there was no indication that anything was amiss. Sometimes I got there as the pilots were having a large scotch in their briefing room - of course I hated to see them drinking alone - took only a few minutes to turn the ELT off and grovel to the guy in the tower!

Now that the old 121.5 ELT's have been replaced with the SARSat there haven't been so many false alarms.

 

[AirScan]

Listening to Boston Center ZBW22 121.350 when I started hearing a strange siren like sound that went on for like five min or more.

Do you remember the date and approximate time you heard this ? There is a LiveATC feed that covers ZBW22-121.350. We might be able to hear it on the saved archive ?