This is the text of an email message sent out by FAASafety.gov this morning:
Potential ELT Problems
Notice Number: NOTC4589
We are not sure how familiar you are with this issue, but there have been several accidents where the installed ELTs have separated from the mount and broken from the installed antenna, resulting in an ELT that does not transmit effectively. The FAA Aircraft Certification Branch has issued guidance in the form of a Special Airworthiness Information Bulletin (available at the link below) aimed at eliminating the problems and we are trying to help them get the message out.
Here is an example:
On August 9, 2010, about 1442 Alaska daylight time, a single engine, turbine-powered, amphibious float-equipped de Havilland DHC-3T airplane, N455A, impacted mountainous tree-covered terrain about 10 miles northeast of Aleknagik, Alaska. Of the nine people aboard, the airline transport pilot and four passengers died at the scene, and four passengers sustained serious injuries. The airplane sustained substantial damage.
The National Transportation Safety Board (NTSB) found that the emergency locator transmitter (ELT) became dislodged from its mounting tray, detached from its antenna, and failed to transmit radio signals to alert personnel of the downed airplane. Aircraft involved in the search and rescue efforts and satellites did not detect any ELT signals. A pararescuer found the ELT loose on the floor of the airplane. The ELT had activated but had separated from its mounting bracket and antenna.
This Special Airworthiness Information Bulletin (SAIB) (https://www.faasafety.gov/
Questions or comments can be addressed to Ms. Charisse R. Green, Aerospace Engineer, Avionics Systems Branch, 470 L’Enfant Plaza, Suite 4102, Washington, DC, 20024; 202-385-4637; FAX: 202-385-4651; email: Charisse.Green@faa.gov