Originally Posted by
Eryeal
(CNN) Investigators have determined that the missing jet was equipped with four emergency locator transmitters, or ELTs, which are designed to transmit a plane's location to an emergency satellite when triggered by a crash or by contact with water, the source added.
The ELTs were at the plane's front door, its rear door, in the fuselage and in the cockpit, said the source, who was puzzled over why they appear either not to have activated or, if they did activate, why they were not picked up by the satellite.
I've seen several comments on them including:
- 4 were included at delivery, but may not still be there.
- They have independent battery packs, which may not have ben maintained.
- There have been two distress frequencies in use (~100Mhz old and ~400MHz new
?), and monitoring of the old one stopped in 2009 so maybe they were using that frequency.
- They can be deactivated from the cockpit.
- They are water activated, but the plane sank before water made it into the ELT housing and the radio waves then don't travel well through water to be detected.
- They are G-force activated, but the surface impact wasn't violent enough to trigger them.
No idea which of these are facts in general or relate to the ones installed on MH370. Has anyone seen anything vaguely authoritative?
Last edited by EsherFlyer; Apr 22, 2014 at 1:38 pm
Reason: Minor typo correction