What is an ELT?
What is an Automatic ELT?
It is an Emergency Locator Transmitter equipped with an acceleration sensor (G-switch), which will automatically activate the ELT emission when a certain acceleration is applied to the unit.This ELT is also connected to the RCP and can be activated and self tested from the cockpit.
There are two types of automatic ELT: Automatic Fixed and Automatic Portable.
Note : A Survival ELT "automatically" activated when placed into water based liquid is not considered to be an "Automatic ELT".
What is an Automatic Fixed ELT (AF) ?
This type of Emergency Locator Transmitter is “An automatically activated ELT which is permanently attached to an aircraft”
What is an Automatic Portable ELT (AP) ?
This type of Emergency Locator Transmitter is “An automatically activated ELT which is rigidly attached to an aircraft but readily removable from the aircraft"
What is a Survival ELT (S) ?
This type of Emergency Locator Transmitter is “An ELT which is removable from an aircraft, stowed so as to facilitate its ready use in an emergency, and manually activated by survivors.”
Note : "An Automatic Portable ELT, (ELT(AP)), as installed in accordance with JAR-OPS 1.820, may be used to replace one ELT(S) provided that it meets the ELT(S) requirements. A water activated ELT(S) is not an ELT(AP)."
(source ACJ-OPS 1.820;Eurocae ED-62A; RTCA DO-204A).