There are two Emergency Locator Transmitters on the 777's I fly, one in the **** and one in the tail. I'm not sure what the Malaysians use, or if they use any at all. The ELT's are supposed to self activate if they get wet, or if they are jarred loose from their mounts by an impact such as a crash landing.

BUT...if they went down in the water, the ELT signal is going to be very weak, depending on how deep it is. If they went down in the jungle, it should be able to be picked up by any aircraft flying over within about 50-100 miles.

ELT's are in most commercial airplanes in the USA, even in a small 2 seater like a Cessna 150. We often pick up ELT signals when flying around the in the USA, because student pilots will hit the test switch and then forget to turn it off, or someone will bump one and set it off unknowingly.

As far as radio coverage, down there in Malaysia, not so much as here in the US of A. I've flown down there from Tokyo to Singapore many times and we are out of both radar and voice communication a good bit of time between the islands. So even if there were a distress radio call made from the plane, it may have been out of range of any receiver when they made it.


There's a lot of water out there, and a lot of jungle too. It will turn up someday, no doubt. They found the Titanic didn't they? It took a while, but they found it.
BUT...the ELT's are powered by an internal battery and it will only last so long, maybe a week, if it was in tip top shape to begin with, maybe less if it was an old battery.