What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

My ELT activated in-flight causing panic to family and friends

MS19087

Well Known Member
So yesterday was my son's birthday. He is at university in Winston-Salem, NC so I figured I'd fly down from Philadelphia in the AM, have lunch and be back by sunset. Due to headwinds, flight was planned for 2 hrs and 40 mins. Apparently 40 minutes into the flight my 406 Mhz ELT activated. This ELT also has GPS data as well. This prompted the Air Force SAR Center in Florida to call my listed contacts. Needless to say my contacts got very spun up. Thankfully I was in the system, using flight following in continuous contact with the many ATC centers along my route. IN ADDITION, I had my APRS tracker operating.

My upset fiancee called my flying buddies who quickly went online to view my APRS track and also FlightAware. The APRS track data gave everyone some comfort that i was likely not in peril. In the meantime when I landed 2 hours after the activation, my cell phone was loaded with missed calls and text messages. With that I tuned to 121.5 and sure enough, I could hear the distress tone. I immediately hit the reset button and it silenced. BTW - Return flight was uneventful with a nice tailwind - home in 2 hrs:). Monitored 121.5 the whole way home when I could.

So help me with a few questions:

1) What would cause my ELT to activate in flight? Air was smooth, no turbulence.
2) I appreciate the matter of urgency the Air Force has when reacting to a distress signal, but why don't they contact the FAA too? I was in the system, the FAA could have provided some info as well as contacting me to silence the beacon.
3) I called the Air Force for further information as to how the event was handled. They told me my beacon was received by the satellite with my GPS coordinates. I asked whether they received multiple locations given that I was moving and at a steady altitude. Their comment was that they received one alert and then acted, when another alerts were received (AFTER ANOTHER SATELLITE PASS) they said that they tend to assume one of the locations was in ERROR!!

Lessons learned:

1) Monitor 121.5 when possible during all flights.
2) I was very happy that I had my APRS tracker turned on - gave friends and family more data to understand my fate. Be sure to let family and friends know how to track you online.
3) A personal locator or APRS tracker is a great tool - however would love to be able to send and receive messages through the APRS tracker. SPOT has this feature which really allows for confirmation of situation.

Thoughts?
 
I would start looking at the telephone cable that connects the indicator on the panel to the ELT.

Perhaps twisting/misalignment at the cheap telephone connectors?
 
All new ELT installations - by definition that would be any 406 MHz unit - require a switch and indicator light within the pilot's view. Do you have one? If the light did not come on, check the wiring. Is it possible you bumped the switch to "on"?
 
All new ELT installations - by definition that would be any 406 MHz unit - require a switch and indicator light within the pilot's view. Do you have one? If the light did not come on, check the wiring. Is it possible you bumped the switch to "on"?

And an audible alert is now required with a 406 install to let you know its been activated.
 
Last edited:
..and monitor!

And an audible alert.

I think we should take this as a reminder to add to our 'cruise' and 'after landing' checklist.

...monitor 121.5

the life ( or embarassment) you save ....may be someone else's too!
 
All new ELT installations - by definition that would be any 406 MHz unit - require a switch and indicator light within the pilot's view. Do you have one? If the light did not come on, check the wiring. Is it possible you bumped the switch to "on"?

My thought was a cable fault could cause an "activate" signal, perhaps without the "transmitting" light coming on.

There are only four wires involved...:)
 
And an audible alert.

Hmmm...I don't believe 406 is required; 121.5 is still legal, just not monitored by satellites.

And..."audible alert"? How? My ELT has no "audible alert" line out to which to connect anything (nor is there any mention of it in the installation manual).

I think perhaps you mean "or" and not "and"?

Could be all wrong, because I think they're deadweight anyway (which is why I have a PLB on the harness), so I went as cheaply as possible. But it's still legal AFAIK.
 
Yep, you are right 406Mhz ELT's aren't required, but they sure are more effective.

By the TSO they have both the switch unit with a visual light and an audible alert that activate when the ELT is transmitting.

If you have a 121.5 ELT it is a dead weight- no one is listening.

If I had to have an ELT, it might as well be doing some good. 406 with GPS input gets the SAR folks right to you if you need it.

I hope it is $700 spent that I will never use.
 
SAME STORY FOR ME

I had the exact same story this summer.
Elt activated by my passenger accidentally without knowing it. ( i was with my 3 brother kids flying back to their home after a week at my house)

The first to know was my wife at home by ( here is search and rescue calling)
!0 minute later i had a radio call from the controller asking me if everything is ok...... because your elt is ON)

I have the audible alert but didn't hear anything with the noise in the aircraft.
The led from the remote switch was hard to see in the sunlight. It didn't catch my attention.

After 5 min to calm down , my wife went on flight aware. I was on a IFR flight plan on VFR condition. She saw me at 10 000ft and moving.
5 minute later she had a call from search an rescue saying that i was OK

Me too, I monitor 121.5 since that day .

Still amaze that my wife can find me in less time than search and rescue. :)
 
How long into the flight did your ELT activate?

I've worked/relayed many ELT reports from the FAA side, almost all false alarms. 121.5 reports are a shot in the dark, sometimes a day or more to track the signal to a hangered aircraft. 406 is much better, I'm not sure how long it takes from the AirForce hearing the first signal (or second satellite sweep), but I've handled numerous situations where the AirForce calls me with a call sign and location of an 406 transmitting in my airspace. I'll find out more on my next Monday.
Personally I think PLB's are a much better emergency device if you have friends/family.
 
406

This past march I had the 406 installed in my super cub. It went off while tied down at the city airport. 4 hours later my wife finally got a call asking if she new where I was. She said ya he is in Oregon and the plane is at the airport. They searched 4 hours and still could not find my plane. Did not find out why it went off. Was not to impressed that after 4 hours they couldn't locate my plane. They where looking all over town and even10 miles out. to say the least I am not impressed with it and not counting on it if I were to go down after this little event. My 406 was installed by an certified mechanic since it was on my super cub.
 
. . . They searched 4 hours and still could not find my plane. Did not find out why it went off. Was not to impressed that after 4 hours they couldn't locate my plane. They where looking all over town and even10 miles out. to say the least I am not impressed with it and not counting on it if I were to go down after this little event. ... .

Funny and sad, but not totally surprising.

In 1974 I was a Service Manager at VW. Long story short, we "lost" a new loaner car, and reported it stolen. 30 days later the bright red bug showed up in my service lane. I walked out to greet the customer (whom I knew). I told her that the car was reported stolen and she nearly fell down laughing. She worked for the sheriffs department at the county headquarters and it was co located with the city police department. She parked the car in the same lot with the squad cars every day and dozens of officers walked right by it each day !!

Gotta go sign up for health care now while it is early. :D
 
Some answers to your questions

I had the exact same story this summer.
Elt activated by my passenger accidentally without knowing it. ( i was with my 3 brother kids flying back to their home after a week at my house)

The first to know was my wife at home by ( here is search and rescue calling)
!0 minute later i had a radio call from the controller asking me if everything is ok...... because your elt is ON)

I have the audible alert but didn't hear anything with the noise in the aircraft.
The led from the remote switch was hard to see in the sunlight. It didn't catch my attention.

After 5 min to calm down , my wife went on flight aware. I was on a IFR flight plan on VFR condition. She saw me at 10 000ft and moving.
5 minute later she had a call from search an rescue saying that i was OK

Me too, I monitor 121.5 since that day .

Still amaze that my wife can find me in less time than search and rescue. :)

1) Same with me - I could not hear the audible warning coming from the ELT.
2) LED on control panel was in sunlight - didn't see it on. It is on right side - probably should be in direct view of pilot OR have another remote indicator on an annunciator panel.
3) Someone asked when it activated . . . approximately 40 minutes into the flight. I definitely did not touch the control panel.

I called ACK Avionics yesterday to discuss possible causes. They claim I was the first report of accidental activation. They asked that I check the wiring, etc, which I will - this unit has been installed for 2+ years with no issues.

On the positive side, when activated it worked! Not worth installing a 406Mhz unit without adding a GPS input (IMHO). . . this should cut down dramatically on the search effort.

I'll report back after I have done a thorough check of the installation.
 
I've been a CAP mission pilot and aircrew member and would tell anyone that the FAA should absolutely mandate the 406 MHz installation on all aircraft. When 406's first came out, a ground team was dispatched to find one at a Class B airport. They located it on a shelf in a maintenance shop in about 10 minutes. This was without any GPS input. The GPS input, by the way, narrows the circle from about 300 yards without GPS to 10 yards with GPS. Hardly worth it considering the 121.5 circle is 20 miles. When our club plane had a mishap that caused an ELT activation at a remote airport, the designated phone person was notified of the activation from Coast Guard Station Hawaii (mishap was in MI) and the location of the plane before the pilot could even call anyone to tell of the mishap. We've had 406's in both planes for almost 5 years now. Would not fly without them.

The audible signal on our installs is located in the tail with the ELT, with a light on the activation switch on the panel. The manual said that when exiting the plane, you will hear that the ELT has been activated.
 
Battery

I know first hand that a low battery has been know to cause the Artex units to activate inadvertently.

I don't know if anyone else mentioned it, but you need to be sure to replace your battery since the ELT was active for more than an hour.
 
406 PLB

I carry an ACR 2881 PLB in my plane. It is located in the cockpit. If I have to abandon the plane, the PLB can go with me. If the plane goes in the water, a 406 beacon in your empennage won't do you much good. A PLB will do everything a larger, more expensive beacon will do with the exception of activate on impact. It also will not accidentally activate! The internal battery is good for 24 - 36 hrs as opposed to 48 hours for the larger units.

My personal view is that 406 PLBs should be allowed as a substitute for the integrated units.

Mugsy
 
Like all ELT's since their very beginnings they are not very reliable, but if they work they do what they are intended to do.
 
Public thanks to Dvalcik & Al RV8

Dave and Al helped calm the situation with family and friends through their efforts of looking for my track on APRS and FlightAware - Dinner on me next week! Happy now David?:rolleyes:
 
This was without any GPS input. The GPS input said:
Thanks for that info. I had wondered why for some reason, Vans elects to NOT use the GPS input on the RV12 ELT, this explains it and reduces my concerns. I would hope the flames from my crash could be seen from 300 yards anyway:p
 
Just another reason that my choice to add an APRS to my experimental was a good choice.
Dave and Al helped calm the situation with family and friends through their efforts of looking for my track on APRS and FlightAware - Dinner on me next week! Happy now David?:rolleyes:
 
ELT Signals

Loose wires, low batteries and jarring events can all have an impact on an ELT to set it off. Monitoring 121.5 before and after each flight is advisable. If you are on a long leg then please by all means "listen" in on 121.5
I have been in Civil Air Patrol going on 8 years and qualified in Urban Directional Finder (UDF) as well as aircraft based positions within the air crew. Electronic signal equipment on the ground and in the air can and do give false readings. I have seen incredible events including signals bouncing off of metal buildings (hanger) to locations over 10 miles away from the ELT. Heavy ore based ground, like what is found in Missouri and Arkansas can displace a signal. We were called out one night for a signal picked up by satellite and reported to Air Force Coordination Center (AFCC) to begin a search in Springfield, MO. We dispatched a team to the local airport (high probablility) as it was within a 5 mile radius of the signal picked up on the first pass of the sattelite. No signal detected by our handheld device at the airport. Second satellite pass showed continuous signal. Second team sent out to triangulate on the ground. We ended up having the local law enforcement contact the manager of Bass Pro (in the wee hours of the morning) to open the store up so we could locate the PLB, still in the showcase, where a curious customer apparently (and accidentally) activated the device.
Also, CAP members are not allowed to enter your aircraft to shut off the ELT if it accidentally activates. CAP will locate the ELT and the owner will be contacted to come out for a visit to deactivate. There are no fines levied or cost for CAP to locate ELT signals. If the owner cannot be located, CAP may wrap aluminum foil around your ELT antenna to mute the signal.
Personally, I agree with others on this site that a PLB wore on your clothing is a good idea as a secondary device to the plane ELT.

Pat Garboden
RV9A N942PT Phase I
Katy, TX

Dues paid
 
Dave and Al helped calm the situation with family and friends through their efforts of looking for my track on APRS and FlightAware - Dinner on me next week! Happy now David?:rolleyes:

More evidence that everything comes with a cost attached when these two are involved! (fkkas). :D

Very glad for this outcome!
 
They located it on a shelf in a maintenance shop in about 10 minutes. This was without any GPS input. The GPS input, by the way, narrows the circle from about 300 yards without GPS to 10 yards with GPS. Hardly worth it considering the 121.5 circle is 20 miles.

Imagine being is a heavily forested area and you are not able to help in your rescue/alerting of rescue assets.

Would you rather that they know your location to 10 meter radius or 300 meter radius?

If you are going to install a 406 MHz unit, get one with integrated GPS.

Personally, I carry a GPS integrated 406 MHz PLB.

I have no expectation that my ELT will work.
 
Let's see if we can get some helpful info written down here for the reading pleasure of this august group.

- 406 ELT's are required to have an audio alerter
This audio alerter normally takes the form of either an external buzzer mounted in close proximity to the ELT or a buzzer contained within the ELT itself. The audio alerter must be stand-alone, therefore it does not have a connection to the aircraft audio system. I have not yet encountered one of these audio alerters that was loud enough to be heard any time the engine is running. Most aren't loud enough to be heard inside the aircraft if you are wearing your headset.
HINT - 406MHz ELT's broadcast on 121.5MHz continuously, save for a less-than-one-second interruption every 50 seconds when the 406MHz signal is being transmitted (in most ELT's). TUNE 121.5 WHENEVER YOU CAN. At a minimum, make 121.5 part of your post-landing check to make sure that last "greaser" landing didn't set off your ELT.

- with only one exception I know of, 406 ELT's are required to have a cockpit control panel with a visible means of indicating the ELT has been activated
While there is a requirement for there to be a visible annunciation of ELT activation, the TSO doesn't contain a meaningful specification as to how visible that annunciator should be, nor is there anything other than vague guidance as to where this remote control panel/indicator should be mounted in the cockpit. Most remote control panels use red LEDs as their indicators, and virtually none of those red LEDs are visible in sunlight - it doesn't take much light to wash them out. It is absolutely reasonable to expect that an ELT could be transmitting without its remote control panel indicator summoning the attention of the pilot while in flight.
HINT - tune 121.5 to check whether the ELT is transmitting!

- many 406MHz ELT's can receive position info from a GPS
GPS can be your helper in being rescued, but keep in mind that GPS also sometimes provides incorrect position, and if your GPS antenna is pointing downward because the airplane has flipped on impact, you're not going to get a valid GPS position. ELT's with a built-in GPS receiver will only have that receiver activate after the ELT is activated. We know it takes time for a GPS receiver to get a position "fix", so the first 406MHz burst transmitted by your ELT likely won't have GPS data - if the airplane is on fire or sinking in water, GPS data may not be transmitted before ELT signals cease to be transmitted. While there is often a large cost penalty for ELT's which interface to the existing aircraft GPS system, they have the advantage of having access to the last known GPS fix and broadcast it in the first 406MHz burst. It's something to think about... The benefit of GPS position data contained in transmitted 406 signals is clear, but let's be sure we also understand its limitations - it's not a panacea but it is one way we can help stack the odds in our favour.

- 406MHz ELT's are supposed to have a lower false-activation rate
While most 406 ELT's have benefitted greatly from advances in G-switch design over the years, some have not. One manufacturer, Artex, has had sufficient G-switch failures that Australia has issued an Airworthiness Directive covering a range of Artex 406MHz ELT's. G-switch failure can lead to uncommanded activation. It happens - be prepared.
HINT - Tune 121.5 to verify your ELT (and anybody else's) isn't transmitting.
HINT - If your ELT has gone off without you being able to confirm why it activated, get it into an appropriately-qualified avionics shop and get it checked out!

- all ELT's have a finite battery life
After intentional or unintentional activation of ANY ELT, the remaining battery life is a critical consideration. 406MHz ELT's are required to record total "on" time and set a "low battery failure" code visible on the remote control panel. Use the self-test function to allow the ELT to tell you whether or not it's battery is safe for continued use. While the lithium batteries for 406MHz ELT's are fairly expensive. If in doubt, don't take a chance - replace the battery, because your life may depend on it.
HINT: Your 406MHz ELT has a built-in test (BIT) function. USE IT!

Another poster has mentioned that he carries a 406MHz PLB. While in many jurisdictions a PLB is not a legal replacement for an ELT, PLB's make a heck of a good backup to your aircraft's ELT's. We fly with two magnetos, a backup means of determining aircraft attitude, a second electrical system, etc. Why not a second emergency locating device? It just makes good sense to do all we can reasonably do to improve our odds of being rescued should an emergency arise.

OK, I'll get off the ole' soap box now. Let's fly safely!
 
I'd also like to add that even with a "standard" 121.5 ELT, you should test it periodically using the remote switch. I have found numerous installations where the remote did not work or never worked (wired with phone cord or bad wiring), remote batteries that were dead (no indication of ELT activation) and on a number of occasions, the ARM switch on the ELT was found in the OFF position :eek:
 
Back
Top