Iran’s aviation authority
said it would not hand over to Americans the recovered black boxes of a
Boeing 737 that crashed on Wednesday, killing all 176 passengers and crew.
Details
Under the rules of the
International Civil Aviation Organization (ICAO), of which Iran, Ukraine
and the U.S. are all members, air crash investigations are led by the
country where the accident occurred.
However, according to
aviation experts, the countries that are capable of analysing black boxes
are few — notably Britain, France, Germany and the U.S.
What is
Black Box?
A flight recorder is an
electronic recording device placed in an aircraft for the purpose of
facilitating the investigation of aviation accidents and incidents.
Flight recorders are also
known by the misnomer black box—they are in fact bright orange to aid in their recovery
after accidents.
There are two different
flight recorder devices:
The flight data recorder
(FDR) preserves the recent history of the flight through the recording of
dozens of parameters collected several times per second
The cockpit voice recorder
(CVR) preserves the recent history of the sounds in the cockpit,
including the conversation of the pilots.
The two devices may be
combined in a single unit. Together, the FDR and CVR give an accurate
testimony, narrating the aircraft’s flight history, to assist in any later
investigation.