ELT Finding After 2/1/09?

[RADIOMAN015]

Has anyone heard officially what CAP will or will not be doing in regarding to ELT signals picked up only on the 121.5 mhz by overflying aircraft, when the SARSAT ceases to monitor/alert for these ELT transmitters? 

As most of you know most the private/recreational aircraft do not have to change to the new 406/121.5 mhz transmitter, BUT only change out when the present ELT transmitter becomes unserviceable.

Our Squadron ES officer attended NESA this summer and came back with the impression that CAP would be getting out of the ELT hunting business.  I know in our state there's no other agency that has airborne DF equipment or ELT specific portable ground DF equipment.

RADIOMAN 

[Eclipse]

Our Squadron ES officer attended NESA this summer and came back with the impression that CAP would be getting out of the ELT hunting business. 

Amazing. I'd sure like to know where that came from, even the most pessimitic on this board will admit that we'll still have ELT's to chase.

The newer elt's will help reduce the number of non-distress missions we get, yes, and the newest ones, in theory, will give an indication of where the transmitter is.

However, as you say, they aren't required.

One of my guys just got back from AFRCC, and the expectation from them is that we will be in the ELT business for the foreseeable future, and in fact good DF skills will become more important.

The briefing he gave at the last staff meeting was that commercial airliners were going to become the defacto SARSAT's, and 121.5 mission would come, in large part, from their calling in a signal.

That means missions we get called on will have a much larger area of probability's, and that the initial roll out for ELT's will likely be multiple aircraft and multiple teams to be able to cover more ground.

[lordmonar]

Okay...let's be clear.

Yes...after 1 Feb 2009 we will be getting less ELT calls from AFRCC because SARSAT will no longer be monitoring 121.5.

But...the FAA and local airports will still be monitoring 121.5 and we will still be getting some calls.

Also note.....you do not nees any special equipment to DF the new ELTS....the 406 signal talks to the satellite and they still have a 121.5 signal for local DFing....so all our L-pers, Trakkers and body shielded handhelds will still work.

What will 1 Feb 09 mean for CAP?   If you get the call to track down a signal....it will much more likely be a real downed aircraft then ever before.  So we will need to be even more ready to respond the ever before.

As for the FAA requiring or not requiring the 406....over time I see that the will become manditory.

[PHall]

What will 1 Feb 09 mean for CAP?   If you get the call to track down a signal....it will much more likely be a real downed aircraft then ever before.  So we will need to be even more ready to respond the ever before.

Hunh?  Still the same old crappy ELT's that we have today. We probably won't see the false activation rate go down until a good number of the old ELT's get retired.

[lordmonar]

What will 1 Feb 09 mean for CAP?   If you get the call to track down a signal....it will much more likely be a real downed aircraft then ever before.  So we will need to be even more ready to respond the ever before.

Hunh?  Still the same old crappy ELT's that we have today. We probably won't see the false activation rate go down until a good number of the old ELT's get retired.

The false activation rate will not go down...but the call out rate will.  Unless the signal is at an active airport with a tower who complains about the 121.5 going off....no one will hear it.  Unlike now...Joe Bloe does a hard landing at the grass field 50 miles from nowhere....AFRCC gets two good passes on the signal and alerts CAP (now it is 0300).   After 02/01/09...no hears it...no one reports it.  The bad side of this...is that Joe Blow has crashed short of said grass strip and no one notices for two days when he was supposed to return from his hunting trip.

So the number of false activations will be the same.......but the number of call outs will decrease....which is a good thing in my opinion.

[Major Carrales]

What will 1 Feb 09 mean for CAP?   If you get the call to track down a signal....it will much more likely be a real downed aircraft then ever before.  So we will need to be even more ready to respond the ever before.

Well said.  Its not the "End of Days" for CAP and ELTs, it is merely going to change the nature of the call outs.

I would say, however, that I was shocked to discover that local/smaller FBOs and managers did not even monitor 121.5 MHz at all.  Some we have encountered did not even know what we were talking about and were amazed when we gave them an impromtu "lesson" in how to use a handheld to "DF" a signal.

Maybe we could provide UDF classes to these folks.

[Flying Pig]

What will 1 Feb 09 mean for CAP?   If you get the call to track down a signal....it will much more likely be a real downed aircraft then ever before.  So we will need to be even more ready to respond the ever before.

Hunh?  Still the same old crappy ELT's that we have today. We probably won't see the false activation rate go down until a good number of the old ELT's get retired.

The problem is, it costs about $7000 to outfit the new 406 ELT's to really work they way they were fully intended to work.

Per the brief at the CAWG Conference by Ron Butts, I believe, our work load is going to increase, because it will require more man power to DF the old ELT's.

He gave an OUTSTANDING briefing on the change over.  From the briefing, The 406 ELT's are not going to be as amazing as they have been made out to be, and there are going to be many large dead zones acros the US that will not be convered by the satellites that receive the signals.

[JoeTomasone]

This has been discussed before, but the long and short of it is:


1.  As stated, the 406 beacons have a 121.5 transmitter for local DFing - and contrary to the rumor mill, I have been unable to locate a manufacturer of a 406 mhz ELT with a 121.5 power output of LESS than the current 121.5's.    (Specifics: Most 121.5 ELTs are rated at 100mw, I have seen 406 ELTs with a 121.5 rating of 100mw and 200mw.   The ONLY 50mw 406mhz units I have found are PLB's -- anyone who has seen a 406mhz ELT with a less than 100mw transmitter, please let me know).   

(Sarbe G2R ELT @ 200mw: http://www.sarbe.com/Downloads/sarbeg2r_elt.pdf)

(Artex G406-4 @ "Minimum 100mw": http://www.artex.net/documents/getFile.php?fileid=392&filename=560-5012+Specification.pdf)



2.  We will have less callouts for false alarms since the beacons are required to be registered with emergency contact numbers - the idea being that they can call the owner who can confirm that it's not an emergency and shut the beacon off themselves.

3.  While the FCC requires 406 ELT owners to register their beacons with NOAA, I haven't yet heard of any penalty for failing to register the beacon, and if you have stale data or are not reachable when your ELT goes off....  We should get the callout just like now.

4.  Not all 406 ELTs have GPS - so you may not get GPS lat/long - however, the satellites are supposed to do a much better job at estimating the position than they do with 121.5 - so the search radius should be smaller; this is a good thing.

5.  Many models of 406 EPIRBS with GPS were tested and several failed to get a GPS signal in many types of circumstances in which they might find themselves (stuck in the superstructure and inverted, underwater, etc).  Some of these may translate to crashes (inverted plane with GPS antenna on top, GPS antenna is knocked off, etc) or accidental activations (parked in the metal roofed hangar and bumped).    Further, some models only get ONE position fix per activation - so it still might not be where the lat/long fix says it is. 

6.  Some people think that we need to get equipment to monitor & DF 406 Mhz -- this is erroneous; the 406 signal is a data burst that lasts less than half a second and is transmitted every minute or so.   We will still be using the same equipment as we have today.   That being said, since it *is* a 5 watt signal, monitoring it would seem to be a no brainer to get AOS.  Even though it should go roughly 1/3 the distance compared to 121.5 Mhz (inverse square law), the transmitter is 25 to 50 times as powerful as the 121.5 transmitter - so it should go roughly 8x the distance in free space, somewhat less due to easier absorption.  Let's call it 5x the distance as a planning figure, shall we?

7.  As mentioned, there is no legal requirement to replace a 121.5 Mhz ELT with a 406 Mhz model, and we may still get callouts based on reports via overflying aircraft, etc. 



So our total missions will likely decrease, but they will change in nature somewhat when they do occur.

[RiverAux]

Am I wrong about thinking that I heard that the Becker DF units can pick up the data bursts from 406 ELTs?

[Eclipse]

Good summary - I might plagiarize the heck out of that in an all-group message.

I think the failure to get a GPS fix will be the biggest pinch point with the new ones.

I've had plenty of situations standing in heavy weather (especially fog) and heavy forest canopy where my robust hand held GPS can't get a fix on enough satellites to establish position, or so few that the error radius on the position gets pretty high.

Hit the side of a hill / mountain, or go down in heavy weather, and the 406 might work, but there will be little or no data attached to it.

[JoeTomasone]

Am I wrong about thinking that I heard that the Becker DF units can pick up the data bursts from 406 ELTs?

You are - and that's not a problem since you won't be DFing a signal that is < 500ms long. 

Picking up and decoding the bursts is mostly pointless since all the data they contain will have been provided by AFRCC.   About the only value in decoding them would be to verify that you're chasing the intended ELT.

[lordmonar]

What will 1 Feb 09 mean for CAP?   If you get the call to track down a signal....it will much more likely be a real downed aircraft then ever before.  So we will need to be even more ready to respond the ever before.

Hunh?  Still the same old crappy ELT's that we have today. We probably won't see the false activation rate go down until a good number of the old ELT's get retired.

The problem is, it costs about $7000 to outfit the new 406 ELT's to really work they way they were fully intended to work.

BS.....did a quick google search and the first hit was for a non GPS 406 for $968...it even fits with the older style mouning bracket by the same company...so no major modifications....just a pop and swap.  I've heard this tired line for too long now.

[SJFedor]

Am I wrong about thinking that I heard that the Becker DF units can pick up the data bursts from 406 ELTs?

You are - and that's not a problem since you won't be DFing a signal that is < 500ms long. 

Picking up and decoding the bursts is mostly pointless since all the data they contain will have been provided by AFRCC.   About the only value in decoding them would be to verify that you're chasing the intended ELT.

Unless it's moving.

And yes, the Becker DFs ARE capable of reading the databursts. It's page 4 i believe.

[lordmonar]

Am I wrong about thinking that I heard that the Becker DF units can pick up the data bursts from 406 ELTs?

You are - and that's not a problem since you won't be DFing a signal that is < 500ms long. 

Picking up and decoding the bursts is mostly pointless since all the data they contain will have been provided by AFRCC.   About the only value in decoding them would be to verify that you're chasing the intended ELT.

The becker can recieve the 406 signal directly but it does not do any DFing off that signal.

[RiverAux]

Well, I wonder about that. 

How far away (obviously depending on altitude) could a Becker pick up a databurst? 

Possibly you could use databurst acquisition as an initial sign that you're in the right area (assuming you aren't picking up the 121.5 signal). 

Also, though it probably wouldn't be anywhere near as easy, could you use wing-null to block out databursts so as to point you in the right direction? 

[Major Carrales]

Am I wrong about thinking that I heard that the Becker DF units can pick up the data bursts from 406 ELTs?

You are - and that's not a problem since you won't be DFing a signal that is < 500ms long. 

Picking up and decoding the bursts is mostly pointless since all the data they contain will have been provided by AFRCC.   About the only value in decoding them would be to verify that you're chasing the intended ELT.

The becker can recieve the 406 signal directly but it does not do any DFing off that signal.

The data burst would only be useful if it could be decoded and read in the aircraft.

[ray]

This has been discussed before, but the long and short of it is:

2.  We will have less callouts for false alarms since the beacons are required to be registered with emergency contact numbers - the idea being that they can call the owner who can confirm that it's not an emergency and shut the beacon off themselves.

Unfortunately while beacons are required to be registered there's no way to enforce this, so false alarm missions won't drop as much as you might think.  I have already been on a 406 mission where the beacon was transferred without updating the registration and I believe California has already seen multiple 406 missions where the beacons were unregistered.

The becker can recieve the 406 signal directly but it does not do any DFing off that signal.

The becker does DF 406 signals, at least according to the manual.  I have not had enough experience to see how well this works in actual cases.  The becker also has a scanning mode which is probably what you want to use when DF'ing a 406 signal.  It will then cycle through 121.5, 243, and 406 so that you are receiving both the continuous 121.5 signal and the intermittent 406 signal.

The data burst would only be useful if it could be decoded and read in the aircraft.

The becker does decode the GPS lat/long information if it's included in the 406 databurst (again, this is according to the manual, I have not seen this happen in person).  Although presumably this is information that you would have gotten from AFRCC anyways.

[JoeTomasone]

The becker does DF 406 signals, at least according to the manual.  I have not had enough experience to see how well this works in actual cases.  The becker also has a scanning mode which is probably what you want to use when DF'ing a 406 signal.  It will then cycle through 121.5, 243, and 406 so that you are receiving both the continuous 121.5 signal and the intermittent 406 signal.

This is highly suspect to me given the short duration of the burst...   I'll do some digging into this.

Edit: Found the manual online and it does indeed decode the burst and SAYS that 406 is valid for bearing mode.   I am still skeptical that it will work that well...   But I'd love to hear from anyone who has tried how well it worked.

http://www.beckerusa.com/products/images/pdfs/SAR-DF-517%20Installation%20&%20Operation%20Manual.pdf

[lordmonar]

I guess the becker is fast enough to get a good LOB on a the 406 signal.

The scanning mode is supposed to use both the low level continous 121.5 and the high power (but short duration intermmitant) 406 signal.

[DNall]

I have a hard time believing "good" LOB, but maybe a general direction would be possible.