In response to recent commercial aviation disasters and new ICAO requirements for autonomous tracking of aircraft in distress, Cospas-Sarsat is finalizing specifications for ELTs for distress tracking (ELT(DTs)) to meet the ICAO requirements. Whereas present ELTs are designed to activate on impact or by manual activation by the flight crew, ELT(DT)s will activate autonomously when an aircraft enters threatening flight configurations that have been predetermined by expert agencies. In this way, ELT(DT)s will allow a plane in distress to be tracked in-flight, prior to any crash, without human intervention aboard the aircraft. ELT(DT)s are being specified using both the existing beacon transmission method (narrowband BPSK) and the second-generation (spread-spectrum QPSK) modulation schemes.