ELT Search

[Flying Pig]

Funny story.....

Yesterday, two helicopters coming over the Sierras reported hearing an ELT on 121.5.  They said they picked up the ELT at Kaiser Peak which is about 10,000 ft. then lost it as they went down into a gorge.  They went back to where they had lost it, and picked it up again.  Their deduction was that the ELT must be on or near Kaiser Peak.  This was reported to the Sheriff's Department dispatch, which was then reported to me at the Sheriff's Aviation Hangar.

Then, deputies began driving to the location, which is basically inaccessible this time of year due to snow.  I told dispatch on the radio and told them over the air that in our area, Civil Air Patrol were the only people who had the equipment and training to find out where this was coming from.  (recruiting plug) So there was no reason for everyone to start randomly driving though the 2700 sq. miles of the Sierras looking for an airplane wreckage on the side of the road.
The Sgt. asked me what I thought.  I told him there is absolutely no way of determining where it is coming from.  They are picking it up when they go back to the peak because they are at 10000 ft. not because its on the peak. It could be ANYWHERE. 
I called ATC and reported it and my Deputy CC and told him to expect a call for an ELT search.  Ironically, my Squadrons 182 was parked right next my Sheriff's 206. Of all the days.
I told the Sgt. that the CAP plane is the only plane I know of that has the equipment to find the ELT. He asked "Arent you a CAP pilot?" I said Yes.  He said, "OK, take it then."   He was more giving me permission to do what I needed to do to find the ELT, not giving me "permission" to fly a CAP plane.  I explained the CAP process to him on missions and he understood.  So, as a precaution, he asked me to launch in Sheriff's 206 and fly up to Kaiser and just look around.  I launched, and at 1500 ft. picked up the ELT on 121.5.  I reported back that seeing as how I picked it up at such a low altitude, this again confirmed that we had no idea where signal was coming from.   Possibly even on the airport.  Then as I was coming back, the signal was crystal clear and then suddenly went off.  Who knows.  However, an R-22 had crashed a few miles north about 2 hours prior.  Our thought is that nobody had thought to turn off the ELT.  Were thinking that was it.  About 30 min later, I went back up and flew around and nothing.  It was just funny that since they know I am a CAP pilot, their reaction was "Go find it."  A CAP mission was activated, but the signal was gone.

Now, the only thing was, the CAP mission was activated about 2.5 hours after the initial signal was heard.  I could have been airborne within about 10 minutes.  I guess it is what it is.   But with the SARSAT satellites no longer putting out the Lat/Long, it would have been a good way to launch and determine it was nothing.  Of course....CAP members like to launch as much as I do.  I told the Sgt. that the huge benefit to CAP was that we would foot the bill if we did it, but that CAP comes and goes and shut off 100's of ELTs per year nationwide without a hiccup.   However, as a Deputy, my department has been handed ELT searches in the past because there were no CAP crews available.  So it was reported to the Sheriff who had no idea what this "Civilian Air Patrol" was talking about and dispatch put out a "Be on the look-out for an Emergency Locator Transmitter" to patrol.  So now you have patrol car-bound Deputies running around looking for this thing like its going to be sitting on the side of the road or something.  So nothing happened.  It would have been nice to have a DF unit in my Dept plane to immediately start DF'ing the signal.

[DG]

Did you do a wing null search?

[Flying Pig]

I tried all of the techniques we use with the DF, but I did not detect any difference.  My Observer was not a CAP member and had no idea what I was trying to do.  Is there something I could have done different with just hearing it on 121.5?  I went from 1500 up to 10,000 and could hear it all the way up and flew probably 25 miles in each direction.  I didnt even have an idea of where to start.  The helicopters picked it up about 35 miles east of the airport and I was still hearing it 35 miles WEST of the airport. Making turns, etc. and heard no change in the tone.

[N Harmon]

Is there something I could have done different with just hearing it on 121.5?

You could have attempted an Aural Search, however that usually works better in flat terrain.

[TXCAP]

I've had good luck going off frequency to narrow down the range.  Start out 121.6, 121.7, ect. until you lose the signal than try to wing null or aural on the last off frequency you had tone.  You can keep going until you are so far off frequency you won't get tone unless you are pretty much over the ELT.

As a suggestion you might consider putting a copy of the CAP Flight Guide in your 206.  Then your observer can turn to the DF audible and wing null sections and read the step by step instructions while you fly. 

[Flying Pig]

Hmmm...interesting.  I didnt know that about switching he channels.

[NIN]

Suggest to your local CAP unit (Hey, ain't you the Commander?) that they make inroads to the local LE community for other times like this.

The Sheriff has a guy working for him that is the commander of a CAP unit in that area, and he's not "CAP-smart?"  Rob, man, if I didn't know better I'd accuse you of falling down on the job! 

Explain how the National SAR system works and how to get in touch with AFRCC (who, as a clearing house, might just be working a signal reported by someone else, like, say, an airliner, in the same area) to kick off a search.  And how to "pre-alert CAP" so that people are leaning forward in the saddle when the call comes from AFRCC.

Next time, dispatch doesn't put out a BOL for a nebulous package, but rather calls the right people and gets the machine rolling.

Or have the Sherriff put a Becker in your plane.

But explain to him that CAP doesn't cost him for this, whereas a Becker will.

EDIT: I was at my National Guard unit one drill weekend when I noticed our Maintenance Officer standing in the middle of the ramp with an Elper. I walked outside, said "Sir, what the hell are you doing?" and he said "Well, you see, aircraft are equipped with this little transmitter and-" I held up my hand "Sir, I'm in CAP, I know what an ELT is.."

He shoved the Elper into my hands and said "Good! Then you know way better than I do how to run this thing!" and ran away.

I spent about 20 minutes bombing around the airport on our aircraft tug (driven by a madman, no less) when we finally noticed the signal moving.  And I looked up just in time to see a big lowboy trailer with a UH-1 on it being repositioned near the hangar.

Sure enough, they'd trailered this thing, hauled it home from Cp Grayling, and never bothered to safe the ELT.  I called our wing alerting officer (then-Lt Col Bill Charles) and said "hey, that ELT you're about to get a call about near Lansing and Grand Ledge? Yeah, I just turned it off..."

AFRCC called me and ask for particulars.  It was fun to close a mission as "SP4 Ninness" not "Captain Ninness."  For awhile they used to jokingly say that I closed a mission before it was even opened. 

[TXCAP]

I have had success using that technique to narrow down an air search to a single airport then land and use it with a hand held to locate the specific aircraft or hanger.  Seems to work well in situations like you describe where other techniques aren't working well or if your DF gear is on the fritz and you're not getting any steering.

We found one a couple days ago doing that after an aircraft with a Becker unit had been searching with no joy.  Similar sounding situation, other than the no mountains in Dallas part, where initial reports from aircraft were 20,000', 10,000', and 5,000' making for a large search area.

[DG]

Hmmm...interesting.  I didnt know that about switching he channels.

You will learn that and much more when you train for and qualify as a Mission Pilot.

I assume from what you said that you did not perform a Wing Null Search.

For Wing Null,

Turn the audio down until it is barely perceptible.

Then put the airplane into a steep turn, e.g., 45 degrees angle of bank, at about maneuvering speed.

If you are using your com antennae to pick up the 121.5 signal, you will lose the audio when your high wing blocks out the signal, and that wing will point to the ELT.

[Flying Pig]

I am a mission pilot.  However, I dont recall the part about changing from 121.5 up to .6 and .7.

I ddi try the wing null, but the signal never really changed.

[jimmydeanno]

I am a mission pilot.  However, I dont recall the part about changing from 121.5 up to .6 and .7.

I ddi try the wing null, but the signal never really changed.

The frequency change is something that I definitely teach GTM trainees.  It works extremely well when your REALLY close.  The L-Per that we have at our unit has 121.5, 121.6 and 121.775 available.   

You know you're really close when you can hear it on 121.6 without the antenna 

[DG]

I am a mission pilot.  However, I dont recall the part about changing from 121.5 up to .6 and .7.

I ddi try the wing null, but the signal never really changed.

Then you need to reduce the audio to barely perceptible levels.  The Wing null doesn't work at high audio.

If that doesn't work, you may have been right over the ELT.

That's when you go off frequency.  That gives you the discrimination that the audio level does not provide when you are right over it.

The off frequency technique is also used when close to the ELT when locating the ELT on the airport with a body block.

These techniques are covered rigorously at the NESA MAS in Indianapolis.

[es_g0d]

*smiles at the learning that occurred*

Off-frequency tuning ... *big grin*

[Flying Pig]

I am a mission pilot.  However, I dont recall the part about changing from 121.5 up to .6 and .7.

I ddi try the wing null, but the signal never really changed.

Then you need to reduce the audio to barely perceptible levels.  The Wing null doesn't work at high audio.

If that doesn't work, you may have been right over the ELT.

That's when you go off frequency.  That gives you the discrimination that the audio level does not provide when you are right over it.

The off frequency technique is also used when close to the ELT when locating the ELT on the airport with a body block.

These techniques are covered rigorously at the NESA MAS in Indianapolis.

OK.  I had the volumn up.  Ill have to try it next time.

[DG]

The Wing Null DF is great fun, especially as you get to fly with precision and track down the ELT.

The person who was with you can be a big help, and even if they are inexperienced, all you need to tell them is to listen very closely and signal you when the sound disappears.

And it is great fun to "spin" the airplane in a steep turn of 45-50 degrees to get the most wing block.  Just sit there in the steep turn.  If you are using your com antennae on the top of the plane, and you are in a left bank (pilot side down) the ELT will be at your 3 o'clock on the heading indicator when the audio disappears.  Watch your heading indicator and note the compass reading at the 3 o'clock.  Works better than noting the 12 o'clock and adding 90 degrees.

For an intense signal, go off frequency and then lower the audio to a barely perceptible level.

For a weak signal, climb to a higher altitude.

For a strong signal, descend to a lower altitude.  Then you can use the terrain to discriminate.  This is especially helpful if there are 2 ELT's going off.  I have had that in actual missions several times, and it happens frequently at NESA MAS.

And in a steep turn at 1500 feet AGL, you are demonstrating why we need to be proficient.  What we do is serious business, especially when we are flying low and slow.

This is standard stuff for mission pilot training and qualification.

If you are getting an audio signal, you can get the ELT.  Every time.

[dbarbee]

Very useful information to us up & coming MP trainees. Thanks for the post and helpful replies!

[Captain Morgan]

Also, no one mentioned that you need to turn off the squelch while doing a wing null.

[es_g0d]

Its not technically always necessary to turn off the squelch, but if you don't you will need to be significantly closer to the ELT before you receive a signal.  If you don't understand why, ask one of our excellent communications experts what squelch does and maybe even how it works.

Incidentally, you may find yourself wing-nulling much more often if you are working with a Becker DF unit.  How is this possible, you ask?  The Becker SAR-DF-517 requires a fairly strong signal to work properly (relatively speaking).  Once you DO receive the signal with a Becker, well, then we all know its pretty easy.  The tough part is getting close enough to the beacon for the Becker to operate.  This is where your unsquelched-radio wing-null skills come into play.  Obtain a signal with an unsquelched radio, do a turn or two to get a wing null direction, and proceed in that direction until the Becker becomes operational.

If you're chasing a 406 technology beacon, I would start my long-range DF on the Becker (in the 406 band).  You will probably (but not always) receive the 5 Watt signal before the homer on 121.5 on your unsquelched radio.  Please send me your "war stories" if you find them in the wild and that's not true.  Like any DF scenario, its important to know the frequency of the 406 beacon.  Aren't they always 406.025 MHz, you ask?  No, not at all.  The reserved frequencies are 406 .000, .025, .050, and .075 respectively.  Ask your IC to quadruple-confirm which frequency the beacon you're chasing is on.

[sardak]

Aren't they always 406.025 MHz, you ask?  No, not at all.  The reserved frequencies are 406 .000, .025, .050, and .075 respectively.  Ask your IC to quadruple-confirm which frequency the beacon you're chasing is on.

One of your friendly ICs checking in. :angel: Yes, check what frequency the beacon is on. The Sarsat Channel Assignment table is shown on page H-2 of Cospas/Sarsat Document T.012, October 2008 version.
                  Freq MHz             Beacon Assigned Dates
Channel A     406.022    Used for orbitography/reference, system beacons only
Channel B     406.025    1982 to 1 Jan 2002
Channel C     406.028    1 Jan 2000  1 Jan 2007
Channel D     406.031    Reserved, not to be assigned
Channel E     406.034    Reserved, not to be assigned
Channel F     406.037    1 Jan 2004 to TBD
-----------------------------------------------------------
Channel G     406.040    1 Jan 2012 to TBD   Planned
This is the last channel with a planned date, but the list continues in 3 kHz steps through Channel S at 406.076 MHz.

A check of a couple of the latest PLBs on the market, the McMurdo FastFind 200 and 210 show they transmit on 406.037 MHz.

The satellite receiver systems are "wideband" to cover 406.0 to 406.1 MHz.

C/S T.012 is a swell read if you want to know about packet theory, probability theory, like calculus, and how C/S calculates how many beacons are allowed on each channel.

Mike

[es_g0d]

I love it when I'm corrected.  I learn every time.    Good stuff, thanks Mike!

By the way, the Becker SAR-DF-517 unit is tunable in the 406 MHz band.  I implied it but did not say that outright in my last post.  Hence the reason to get the proper frequency.  Clearly Mike's research is much better than my memory!