# How to lose an aircraft?

I've just read this article about the disappearance of QZ8501 and was surprised by the following statement:

Even with automated beacons (we can assume these weren’t used, weren’t on board or were intentionally disabled) and EPIRBs, losing an aircraft is actually not that difficult.

Now, is it?

I was under the impression that if Breitling can make a watch with a 406 MHz distress beacon, a €70 million aircraft must surely be equipped with an automated ELT that can start to transmit automatically and whose signal can be picked up by [LE/GE]OSAR.

As it seems, US-registered civil aircraft are not required to carry 406 MHz ELTs while aircraft registered in Australia must be equipped with ELTs that operate on both 406 and 121.5 MHz (see the same reference).

Can you shed some light upon what is the current state of ELT regulations, how ELTs fitted to commercial aircraft operate in case of distress (automatic/manual?), what are the relevant regulations for EU-registered aircraft, and how can one lose an aircraft when all these systems operate?

I don't buy that “losing an aircraft is actually not that difficult” if all available technology is used (even assuming little redundancy and an adequate price range).

• A general remark (not sure what the article says) but an ELT dropped in a big body of water like the ocean, is pretty hard to find. The range of the signal in water is severely limited (compared to the size of an ocean), and you need to take into account that the distance from the ocean floor to the surface which might be substantial as well. – falstro Dec 29 '14 at 22:57
• @falstro The article is focused on non-emergency radar contact, briefly mentions that GPS is a one-way connection, and ELTs are only mentioned in the quoted bit (apparently as EPIRBs). While you raise a good point relevant to the process of actual rescue, we are only interested in locating the crash site for which the last transmission above ground should suffice. 406 MHz ELTs transmit a burst of signal every 50 seconds, which, assuming GPS data are included, should greatly reduce the search area (even without GPS, it should be approximately 3 nm). – Harold Cavendish Dec 29 '14 at 23:06
• It is now confirmed that QZ8501 wreckage has been located close to the position of the last contact. – Jan Hudec Jan 3 '15 at 21:37
• Actually, when crossing the big pond from Europe to the Caribbean I sometimes think about how incredibly difficult it would be to find a plane back when we haven't seen a ship or plane but only water for 9 hours straight...... There is a lot of surface on the earth when you think about it.... – Ron Oct 23 '15 at 20:53