Sen. Stevens Plane Crash, NTSB Issues
January 6, 2011 - The National Transportation Safety
Board on Wednesday issued two safety recommendations to
the Federal Aviation Administration requiring a detailed
inspection of all emergency locator transmitters (ELT)
installed on general aviation aircraft to ensure that
their mountings maintain their retention capabilities
during an accident sequence.
ELT is designed to broadcast a signal through an
externally mounted antenna that contains the aircraft's
registration information and the global positioning
system coordinates of the original signal. Also, the
"homing signal" can be detected locally by other
aircraft, air traffic control facilities, or rescue
personnel who use a compatible receiver.
"In this case, the airplane was equipped with a
functioning 406 megahertz ELT, which can be a tremendous
aid to search and rescue operations," said NTSB Chairman
Deborah A.P. Hersman. "But this vital life-saving
technology won't do anyone any good if it doesn't stay
connected to the antenna."
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 flight was operated by General Communication, Incorporated (GCI), Anchorage, Alaska, under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The flight originated at a GCI-owned remote fishing lodge on the southwest shoreline of Lake Nerka about 1427 and was en route to a remote sport fishing camp on the banks of the Nushagak River, about 52 miles southeast of the GCI lodge.
the time of the accident, marginal visual meteorological
conditions were reported at the Dillingham Airport, in
Dillingham, Alaska, about 18 miles south of the accident
site; however, the weather conditions at the accident
site at that time are not known. No flight plan was
filed. About 1815, GCI?s onsite lodge manager contacted
the fishing camp to inquire about the airplane's
proposed return time and was told by fishing camp
personnel that the airplane had not arrived.
The lodge manager attempted to contact the pilot by phone and radio. Lodge management personnel were unable to locate the airplane and initiated an aerial search along the pilot's anticipated route. Additional personnel in airplanes and helicopters voluntarily joined the search for the missing airplane. The airplane was officially reported overdue to the FAA at 1859.
|ELT tray with webbed strap mounted on sidewall of accident airplane|
|Artex ME406 ELT and separate mounting tray|
ELT in mounting tray,
The de Havilland
DHC-3T airplane was equipped with an Artex ME406 ELT, which was designed
to broadcast a 406 megahertz (MHz) signal, via an externally mounted
antenna, that contained contact information for the airplane owner and
the global positioning system coordinates of the originating signal.
When activated, the signal would be received by orbiting satellites and
relayed to appropriate rescue organizations. In addition, the ME406 ELT
would broadcast a 121.5 MHz ?homing signal? that could be detected
locally by other aircraft, air traffic control facilities, or rescue
personnel who use a compatible receiver.
An ELT is
activated automatically by crash forces and then transmits radio signals
containing the airplane?s identification and location, which are used by
search and rescue organizations. These transmissions are a key component
in the rapid location and rescue of passengers once an accident has
volunteer airborne search personnel located the wreckage near the
anticipated flight route, in steep, heavily wooded terrain, about 19
miles southeast of the GCI lodge. After the search team located the
wreckage site, the weather deteriorated. Poor weather and night
conditions prevented military pararescue personnel from reaching the
accident site until the following morning when they transported the
passengers from the scene. The pilot and four passengers, including
former U.S. Senator Ted Stevens, sustained fatal injuries. The other
four passengers were seriously injured.
investigation of an amphibious float-equipped de Havilland Dash-3T
(DHC-3T) airplane accident, 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.
United States Air Force Special Operations Command (AFSOC) and Air
Combat Command (ACC) operatives tasked with recovery and medical
treatment of personnel in humanitarian and combat environments. They are
the only members of the DOD specifically organized, trained and equipped
to conduct personnel recovery operations in hostile or denied areas as a
Also known as
"PJs" (Para Jumpers), these special operations units are also used to
support NASA missions and have been used to recover astronauts after
water landings. They are attached to other SOF teams from all branches
to conduct other operations as appropriate. Of the 22 enlisted Air Force
Cross recipients, 12 have been awarded to Pararescuemen. They wear the
maroon beret as a symbol of their elite status. Part of the little-known
Air Force Special Tactics community and long an enlisted preserve, the
Pararescue service began commissioning Combat Rescue Officers early in
the 21st century.
investigator and Artex personnel examined the ELT unit at Artex
The precise reason that the ELT did not remain attached to the airplane is not known. However, it is possible that the ELT was not installed correctly, either at the time of installation or after the periodic inspections. A number of ELT manufacturers5 employ mounting designs similar to the one used for the Artex ME406; the ELT unit is attached to a mounting tray by various types of straps.
In all cases, the
retention capabilities of each system are dependent on proper
installation, and any looseness or misalignment of the retention strap
would increase the chance of accidental detachment of the ELT. The NTSB
concludes that proper installation and inspection of ELT units is
imperative to ensure they remain connected to the antenna and maintain
functionality for rapid notification of aircraft accidents and prompt
Because so many
ELTs employ a mounting strategy similar to the Artex ME406, the
The NTSB concludes
that a thorough inspection of all installed ELTs could identify and
correct any existing mounting problems. Because of the critical
importance of having an operational ELT, the NTSB recommends that the
FAA require a detailed inspection, during annual inspections, of all
ELTs installed in general aviation aircraft to ensure that the ELTs are
mounted and retained in accordance with the manufacturer?s
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