This document provides an overview of aircraft black boxes, which are flight data and cockpit voice recorders located in aircraft tails. Black boxes, which are actually orange, record data to help investigators determine the cause of accidents. Over time, recording technology has advanced from magnetic tapes to solid-state devices, allowing more data to be stored reliably. Black boxes contain crash-survivable memory units that can withstand extreme impacts, heat, and pressure to preserve critical recording data.

1. WELCOME TO
A SEMINAR PRESENTATION
ON
“BLACK BOX INSIDE
AIRCRAFT”

2. Black boxes - which are actually orange
- are a group of data collection devices
mounted in the tail of an aircraft.
Dr David Warren, an Australian aviation
scientist, proposed a flight recording
device and by 1958 he had produced
the prototype "ARL Flight Memory Unit".

3. Computers have now replaced
magnetic tape, meaning the devices
can record more data and are far more
likely to survive an impact.

4. World’s first flight memory recorder
(Black Box)

5. Generations of Data Recorders
First Generation Foil Recorders
Second Generation Tape Recorders
Third Generation Solid State
Recorders
Components of the Black Box
CVR - Cockpit Voice Recorder
FDR - Flight Data Recorder

6. there are several microphones built into the cockpit
to track the conversations of the flight crew. These
microphones are also designed to track any
ambient noise in the cockpit, such as switches
being thrown or any knocks or thuds. There may be
up to four microphones in the plane's cockpit, each
connected to the cockpit voice recorder(CVR)

7. Any sounds in the cockpit are picked up by these
microphones and sent to the CVR, where the
recordings are digitized and stored. There is also
another device in the cockpit, called the
associated control unit, that provides pre-amplification
for audio going to the CVR. Here
are the positions of the four microphones:
- Pilot's headset
- Co-pilot's headset
- Headset of a third crew member (if there is a
third crew member)
- Near the center of the cockpit, where it can
pick up audio alerts and other sounds

8. • Flight Data Recorders
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.

9. 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.

10. Built to Survive
• The only devices that survive are the crash-survivable
memory units (CSMUs) of the flight
data recorders and cockpit voice recorders.
Typically, the rest of the recorders' chassis and
inner components are mangled. The CSMU is a
large cylinder that bolts onto the flat portion of the
recorder. This device is engineered to withstand
extreme heat, violent crashes and tons of
pressure. In older magnetic-tape recorders, the
CSMU is inside a rectangular box.

11. Using three layers of materials, the CSMU in a
solid-state black box insulates and protects the
stack of memory boards that store the digitized
information.

12. Aluminum housing - There is a thin layer of
aluminum around the stack of memory cards.
High-temperature insulation - This dry-silica
material is 1 inch (2.54 cm) thick and provides high-temperature
thermal protection. This is what keeps
the memory boards safe during post-accident fires.
Stainless-steel shell- The high-temperature
insulation material is contained within a stainless-steel
cast shell that is about 0.25 inches (0.64 cm)
thick. Titanium can be used to create this outer
armor as well.

13. There are several tests that make up the crash-survival
sequence • Crash impact
• Pin drop
• Static crush
• Fire test
• Deep-sea submersion
• Salt-water submersion
• Fluid immersion
• After finding the black boxes, investigators take
the recorders to a lab where they can download
the data from the recorders and attempt to
recreate the events of the accident.

14. This process can take weeks or months to
complete. In the United States, black-box
manufacturers supply the NTSB with the readout
systems and software needed to do a full analysis
of the recorders' stored data.
• Modern flight data recorder
• The recorders made of strong materials, such as
titanium, and insulated to withstand a crash
impact many times the force of gravity,
temperatures of more than 1,000 degC for up to
30 minutes and the immense pressure of lying
on the seabed.

15. Modern black boxes record up to 300 factors
of flight including:
-Airspeed and altitude
-Heading and vertical acceleration
-Aircraft pitch
-Cockpit conversations
-Radio communications