Black Box (FDR)

The flight data recorder (FDR) is designed to record the operating data
from the plane's systems. There are
sensors that are wired from various
areas on the plane to the flight-data
acquisition unit, which is wired to the
FDR. When a switch is turned on or off, that operation is recorded by the FDR
In the United States, the Federal Aviation Administration (FAA) requires that commercial airlines record a
minimum of 11 to 29 parameters,
depending on the size of the aircraft.
Magnetic-tape recorders have the
potential to record up to 100
parameters. Solid-state FDRs can record more than 700 parameters. On
July 17, 1997, the FAA issued a Code
of Federal Regulations that requires
the recording of at least 88 parameters
on aircraft manufactured after August
19, 2002. Here are a few of the parameters
recorded by most FDRs:
• Time Pressure
• Altitude
• Airspeed
• Vertical acceleration
• Magnetic heading
• Control-column position
• Rudder-pedal position
• Control-wheel position
• Horizontal stabilizer
• Fuel flow

Solid-state recorders can track more
parameters than magnetic tape
because they allow for a faster data
flow. Solid-state FDRs can store up to
25 hours of flight data. Each additional
parameter that is recorded by the FDR gives investigators one more clue
about the cause of an accident.