One black box would stay with the plane. The other would be prepped to be ejected should the plane descend below a set altitude and not be under the control of a control tower.

In other words, when the plane went below 1,000 feet, and a control tower did not deactivate the black box ejector, the black box would be dropped away from the plane.

It could be encased in a flotation device, settle gently to the ground with a parachute, and have a GPS transponder set to beam its location from the moment it's ejected. It would be easy to find, nearly impossible for someone on the plane to tamper with, and provide a ready signal and up-to-date information about the plane's condition direction, and possible location.

Oh, certainly, a determined individual could descend to 900 feet and be rid of the device, but in an emergency situation it would make locating the aircraft far easier.

Aircraft are never "under the control of a control tower". They are always under the control of the pilot.

There is no requirement that they even talk to a control tower in many places.

Nice thought, but it is clear you have no knowledge of how aircraft fly and how they navigate.


A much simpler answer is for them to transmit periodically some basic parameters- location, altitude, direction, speed. That is easy to do with technology we have now.

Or do the pilots just willy-nilly land wherever they please?

And after a commercial aircraft takes off, how often do they maintain cruising speed below 1,000 feet? Or does such a dip in altitude only reasonably take place while preparing to land?

Please enlighten me. I have no idea how planes fly.

Airspace is "controlled" only to the extent that in some (not all) areas around airports, the tower knows who is within the five mile radius inbound or outbound. The controller tells the pilot if he is clear to land, or if he must circle or steer to get in line. At the largest airports, the controller may direct the plane to get in line with other planes. But it is the pilot who is flyiing the plane, not the controler.

Cruising speed? They never do cruising speed at low altitude. The speed limit below 10,000 feet is 250 kts, with few exceptions.
Jets usually fly less than 200 knots when approaching an airport. Approach speed is typically from 120 to 160 knots for most Boeing jets. http://www.boeing.com/assets/pdf/commercial/airports/faqs/arcandapproachspeeds.pdf

Cruising speed for jets is usually much higher, and is not reached until they are at a cruising altitude.

Low level flight is usually only for landing.

If a plane crashes close enough to a control tower to see it, you don't need anything special to find the flight data and voice recorders.

you only need an ejectable flight recorder when the crash site is a thousand miles or more from land.
but then again, I said the answer previously- its not a flight recorder, but rather real time data being transmitted during flight. Even if it is simply a one-second burst of flight data every two or three minutes, you'd get most of the data you need to figure out where to look.

A simple one-second databurst report of Position, speed, direction, altitude, spit out every two or three minutes, and you could narrow the crash site down significantly.

... should have been part of the search effort from the first few days. D'uh.

as a "black box detector"

Once again, reporters are writing things that don't exist.


All that is is an acoustic hydrophone (listening mic) that is towed. Yes, they have been listening with them since day one.

Many Navy ships are equipped with them to begin with, although not all.

Even now it doesn't look like they really know just where to look.

They WILL JUST find the black box, IN THE NICK OF TIME....

Except the black box only lets them know what happened a couple of hours BEFORE crashing into the sea.
Good luck with finding out anything.

They've known where it is...this is all a diversion....I just wish I knew a diversion from what?

this is getting tiresome

I predict two more weeks of this uselessness.