A few recent posts discuss mirrors for signalling if trapped in a car. Our retired CHP officer, old bald guy and I have both been involved in searches for vehicles that have gone over the side. Some of our canyons in California are so deep and covered in dense chapparel the best of mirrors are hindered. A portable, self powered emergency horn such as those used on small boats is a good idea. Like any limited life unit, make sure somebody is listening. Sometimes a car can be completely hidden. Our periodic brush fires always reveal a vanished motorist from the past.

And not just in So Cal either. We had similar experiences on the Mt. Lemmon highway near Tucson. I would rather use a whistle than a horn - longer active life and a more distinctive sound. Of course, like mirrors, most vehicles come with a horn these days.

How do you know when someone is listening?<br><br>I'm not being facetious; there have been a number of cases where downed pilots have turned off their ELTs to "save the batteries", thereby prolonging the search. (Well, I know of one; I'm sure there have been others.)<br><br>The general rule for an ELT is:if you need immediate assistance (e.g. someone is badly injured), turn it on and leave it on. If you're not in imminent danger, turn it off until the SAR time on your flight plan (at which point you know the authorities will be starting to look for you), then turn it on and leave it on until (a) someone finds you, or (b) the batteries run out. <br>That supposedly gives you the best shot at being rescued if you know there's an organized search for you. Of course, a radio signal will carry much farther than a loud noise, so presumably, if they search party were close enough to hear the horn, you'd be able to hear them. Is that a reasonable assumption?

Relying on the vehicles horn is not the best way to go. It doesn't take much of a front end impact to shatter the vehicles battery, leaving you dead in the water, so to speak...<br><br>A whistle on your person, and a canned air horn in the trunk is cheap insurance...

I've seen where vehicles have gone off the road and down into deep ravines and canyons in our area and they weren't visible at all from above or below and the tangles of brush and scrub oak would make it near impossible to signal with a mirror. In many cases I would think that getting out of the vehicle is out of the question because of steep angles, the precarious possition of the vehicle or injury and a whistle can be ruled out in others because of the inability to blow on it, due to injuries. An airhorn with extra cylinder or a battery operated horn would probably be good to carry with the other devices for all around trouble. Kinda makes a case for keeping the emergency kit in the backseat instead of the trunk don't it?

I remember reading of a couple incidents, years ago in the LA Times, where drivers went off a road and were trapped for days. I recall them saying they could see sections of the road in the distance, and helicopters and aircraft flying overhead, but they had no way to signal them. A mirror would have helped unless the angle of the sun precluded them from getting a good reflection. These incidents happened years before cell phones were in common use. <br><br>If I recall correctly, a horn wouldn't have been much help given the din of traffic, especially since no one was searching for these drivers. A mirror is one option, but one of the best if sunlight is accessable to the trapped occupant. A horn, though less useful in the particular situation in the TImes stories, might be useful in other scenarios. <br><br>I always keep road flares in my car, which might be useful in some scenarios, if there's no risk of me starting a fire that could trap and kill me. <br>

You are right about the back seat thing...

I always kept my emergency equipment under the passenger seat in the front. That way it can´t hit at head level and it doesn´t get caught between the pedals when the car stops suddenly. I once saw a bottle roll behind the pedals during a hard stop. After the driver interrupted breaking shortly, the bottle kept the pedals up. It wasn´t exactly a pleasing experience.

I found the two incidents in the Los Angeles Times Archives. Since they are copyrighted, I summarized the two incidents below.<br><br>Mar 21, 2000<br> <br>Lee Risler's van ran off the S. Gabriel River Freeway near Downey. His van went down an embankment and turned over. His left arm was mangled and trapped under branches that punched through his windshield. Risler, 53, using a pocket knife tried to cut off his left hand, cutting at the wrist and finger of his left hand. The amputation attempt was unsuccessful, and he was trapped for 2 1/2 days waiting for help. <br><br>By chance Caltrans workers discovered his overturned van and he was rescued.<br><br>After the rescue, doctors amputated his left arm.<br><br>..........................................................<br><br><br>Dec 26, 1999<br><br>Jolene Donohue, 52, was trapped in her car after it ran off the Foothill Freeway in Sylmar. The vehicle rolled over and came to rest on its wheels 70 feet below in rugged terrain. The crash jammed her doors shut and cut electrical power to her Mazda 626, and wedged her in. The widow from Santa Clarita operates her own industrial welding distribution and supply business. She was trapped in her crumpled car for two nights before being rescued. <br><br>A passing motorist stopped beside the freeway for a rest and spotted her car by chance. <br>............<br><br>Note: They were found by chance: they could have gone undiscovered much longer. Food and water would have helped. These incidents are less likely in todays cell phone saturated society. If you don't have a cell phone, get one.<br><br>Also they were all in their early 50's, which must be a risk factor. :-)