ELTs are a joke

I've said it before, though I haven't done an extensive web search on it, There's gotta be an elt available that sends one short burst with your exact GPS location to a satalite, instead of having the boy scouts try to hunt down an AM signal with a directional antenna, while the transmitter is operating continuosly draining those questionable D cells that have been in the unit for...how long? Hokey Smokes! let's get caught up with the '90's. It's crazy, flying along and having center call you to ask if you hear an elt signal while you're at FL310 over the LA basin. Yeah, we hear it, so now what? If it were a gps signal, center would know right away it's just a helicopter sitting in the hanger an hour after a firm landing. A millisecond burst would require very little power, and could encode position, aircraft type & 'N' number and whatever else. The signal only needs to be sent once, and would save time, money, and lives. A hunter or hiker or pilot could add a brief text message as well, to indicate urgancy. Oh, one other thing, considering the cost of a gps & transmitter, it should be affordable to anyone, maybe the price of a 'chute or less. Why don't we all have these?

The 1.6 GHz EPIRBs are already available:

The 1.6GHz EPIRB uses the INMARSAT satellites in geostationary orbit. These satellites do not fly around the planet and appear to remain in one fixed spot over the earths surface, (the stationary part of geostationary).

They are equipped with a GPS receiver so that when they are activated the alert signal, beacon ID and beacon position are transmitted.

See http://www.navtec.de/english/epirb2.htm

Tony V.

Most because a TSO'd 121.5 MHz ELT costs around $200, whereas a TSO'd 406 Mhz ELT costs $5000+ (a GPS with a 429 bus will cost you a few thousand more). You can get a marine 406 MHz ELT for under $1000, but they don't have a G-switch...

Sorta off-topic, but sorta not:

Last year, me and a couple of friends sitting around the table at Air Sailing had a big ol' discussion about that. One of the controversial ideas that came out of that was that perhaps the best predictor of accident survival was how long it took emergency crews to reach the accident site. What we figured is that glider pilots need something like the OnStar system that they put in Cadillacs and such.

What we hashed out was a GPS-enabled system capable of sensing a crash impact, and further capable of determining the proximity to civilization and the nature of the surrounding terrain. With that information at hand, the box would assess the impact energy and location, and place a satellite call for a MediFlight helicopter or ambulance as appropriate.

Just some into-the-box thinking.

Bob K.

Though much better thatn the 121.5 MHz units, I don't believe that the 406's transmit GPS coordinates like the 1.6 GHz units do - they use doppler shift instead. My understanding is that the 406 MHz units provide a 1KM resolution. Much better than the 121.5's but if you go down into a forest.... not good enough, IMHO. See http://www.navtec.de/english/elts.htm

Tony V.

Also a bit off topic but this summer (July), a club member made an 'off-field landing' in a forest in an LS4-b. He was slightly injured and was trapped in the aircraft. He radiod his GPS cooordinates to a club tow plane, 20 miles away. The plane landed at the gliderport, loaded an oberver with a portable GPS and set off. Even though they had the exact position, it took several minutes to spot him though the forest canopy. They circled over the crash site and guided rescuers until help arrived.

The police later credited the tow plane crew for significantly reducing the rescue time.

Tony V.

A 406 MHz ELT can transmit GPS position. I believe EPIRB was designed primarily for marine applications. The primary receivers are on geostationary satellites, which may not be very helpful if you happen to be in a canyon, or on the wrong side of a mountain...

A single tone modulated am transmitter can consist of very few parts. You're thinking something that can be activated after the crash has already occurred, highly unlikely all that circuitry would function after a crash.

However, let us know how your development comes along. Just remember the market is too small to pay more than $50 per year to the developer.

Sorry, dud, but digital encoding may be relatively simple and now small, but making complex and accurate is going to blow the hell out of development costs.

Probably not for SAR since PLT's work fine BUT what a great idea for team flying.

I note that Winpilot can plot team members position on the moving map display. Link members of the team with APRS and feed the data to Winpilot and each could see the position of the others.

Bill Daniels

Hi Gang, me again. Let's be realistic about ELT's. Automatic activation in a crash situation has got to have a very low sucess probability. The ship and therefore the ELT antenna, may very well be upside down. The ELT may be damaged in the crash. At best, we can't expect a search plane on scene in anything less than 24 hours.

So what's our best way to communicate a distress signal? I would think it's our aircraft radio. Transmit on 123.3 and 123.5 to your buddies or anyone who answers. The local soaring operation should send out a search plane in the evening. In a contest, you can expect a search to be activated about 7:30 in the evening. I think it would be a good idea to carry a hand-held radio, as a back-up. If your aircraft radio is functioning (transmit light on) but the antenna lead is broken, then I would pull out as much wire (RG-58) as I could and strip away 24 inches of the outside (grounding) shield. Then get your new antenna as high as possible. The survivor that started this thread, could have done this and then tied the end of his antenna to a parachute shroud line and the other end to a stone. Toss the rock over a tree branch and start calling, MAYDAY MAYDAY MAYDAY on all frequencies that might have listeners. Don't forget about 121.5 (emergency freq) To conserve your battery, the best time to brodcast is 15 to 18 and 45 to 48 minutes after the hour. Any SAR forces will be listening at these times.

I cary a small survival kit with 2 quarts of bottled water in my ship, but what if I bailout? So, I just added several book matches and a very thin pocket knife to my parachute inspection pouch holder. With that parachute, a knife and matches, I feel I would have a fighting chance.

Now, lets all conduct our soaring activities in a manor that doesn't require any of the above. JJ Sinclair