[Zancarius]

> Btw, what's the transmission range of a black box? If it's 10,000 ft down, how close do you have to be to hear it?

Apparently 2-3 kilometers according to [1], which I found in the comments from here [2].

[1] http://www.hydro-international.com/issues/articles/id1098-Ai...

[2] http://www.aticourses.com/blog/index.php/tag/side-scan-sonar...

[melling]

So, if the plane is traveling at 13 km a minutes and you have a 20 minute window, it's going to take a long time to find it.

Doesn't the technology exist to detect low power signals from a much greater distance? The US military must be able to do it?

[teamonkey]

The black box pinger isn't really designed to locate a crash site, IIRC, it's to locate the black box within a crash site that could cover several square kilometers.

[adanto6840]

I'm more surprised that there isn't a single (imagery-related) satellite that would, over the last 24 hours or so, have taken imagery (or been able to be re-assigned to do so) of the area(s) of interest.

If for nothing else than to rule out some areas / possible outcomes... But yeah, very far out of my realm of expertise, though I do hope to finish my PPL fairly soon & am an avid AVHerald & LiveATC follower! :-)

http://www.liveatc.net/forums/

http://www.avherald.com/

[Maxious]

You can look at Landsat imagery for some of the search area http://www.geosage.com/Special/Landsat8_Flight370.pdf

[Zancarius]

> Doesn't the technology exist to detect low power signals from a much greater distance?

The pingers are sonar (well, sonic, but detected with sonar), with all the limitations that implies.