The Federal Aviation Administration’s Safety Team recently issued a special notice advising aircraft owners of a potential problem with the newer 406 MHz Emergency Locator Transmitters.
Using the example of the high profile crash of a DeHavilland Beaver on August 9, 2010 that killed former Alaska Senator Ted Stevens, famed pilot Terry Smith and two other passengers who perished, the NTSB and the FAA have found the mounting of the 406 Mhz ELTs.
The FAA has found that there is a problem with the installation of some of the units and has advised aircraft owners about this with a notice called Potential ELT Problems. The special airworthiness Information Bulletin was issued on Feb. 21, 2013.
The ironies of this accident are that the aircraft was not equipped with ADS-B, the aircraft corporation was not a member of Alaska’s Medallion Foundation both championed by Sen. Stevens.
As Alaska’s former senior Senator Stevens helped the Medallion Foundation receive federal grant funding for its aviation safety programs. Stevens even went so far as to say, “If a carrier is not a member of Medallion, don’t get on the plane.”
Despite the warnings, awareness and professionalism of the pilot and aircraft owner, the detail of the ELT’s mounting and subsequent failure to successfully transmit its signals show yet another irony of the DeHavilland’s accident information. The information bulletin states the following details:
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.
The newer 406 MHz ELTs were mandated in 2009 by a federal ruling. The 406 ELTs replaced the 50+ year old 121.5, 243 MHz transmitters which are no longer monitored by satellite rescue coordination centers and Search and Rescue units nationwide in the U.S.
Rob Stapleton can be reached at: robstapleton(at)alaska.net