Aircraft Transponder What's the reason why auto-detaching buoy transponders don't work on commercial aircraft?
They do. They're called ELT's. However, like all radio equipment, they have a limited range. One must be close enough to detect it's signal. They are generally mounted in the aft cabin above the ceiling panels. There are water-activated types and G activated units. One would assume that since this was an ETOPS aircraft that it was equipped with a water-activated type, but sometimes they substitute aircraft and 'cheat'. If it has a G unit on it, the impact would have to be great enough to activate the pinger.
However, they are not "auto detaching", why would you want to to flow away from the aircraft in the current?
High Quality Content by WIKIPEDIA articles The Transponder Landing System (TLS) is an allweather, precision landing system that uses existing airborne transponder and ILS equipment to create a precision approach at a location where an ILS would normally not be available.Conventional ILS systems broadcast using a number of single purpose antennas. One, located just off the end of the runway, provides a fanshaped signal for azimuth direction (side to side) and another located beside the runway provides elevation to indicate a standard glideslope. ILS installations also include one or more marker beacons located off the end of the runway to provide distance indications as the aircraft approaches the runway. This complex set of antennas is expensive to install and maintain, and are often difficult to site in builtup areas. Author: Surhone, Lambert M./ Timpledon, Miriam T./ Marseken, Susan F. Binding Type: Paperback Number of Pages: 80 Publication Date: 2010/11/18 Language: English Dimensions: 9.02 x 5.98 x 0.19 inches
High Quality Content by WIKIPEDIA articles In telecommunication, the term transponder (shortfor Transmitterresponder and sometimes abbreviated to XPDR, XPNDR, TPDR or TP) has the following meanings: An automatic device that receives, amplifies, and retransmits a signal on a different frequency (see also broadcast translator). An automatic device that transmits a predetermined message in response to a predefined received signal. A receivertransmitter that will generate a reply signal upon proper electronic interrogation. Author: Surhone, Lambert M./ Timpledon, Miriam T./ Marseken, Susan F. Binding Type: Paperback Number of Pages: 100 Publication Date: 2010/05/19 Language: English Dimensions: 5.98 x 9.01 x 0.23 inches