Black Box: How it works and Why is it so important?

Share on facebook
Share on twitter

Every time a plane crashes or anything bad happens to the plane, one thing the investigators must look for is the so-called black box or the more accurate name “Flight Data Recorder (FDR)”. Since the black box recorded a lot of information that will help investigate the cause of the crash.

Today, ACES Aviation, aviation experts, will help you take a good look at black boxes, what it is, how it works, its special features, as well as how it contributes to plane crash cases.

In this article:

  1. What is a Black Box?
  2. What is Recorded in the Black Box?
  3. How can the Investigators Locate the Black Box?
  4. How does the Recorded Data help the Investigation?

What is a Black Box?

The Black Box or the Flight Data Recorder is the instrument used to record every activity of the aircraft during the flights. It will record everything from time, pressure altitude, fuel flow, and as far as every sound in the plane. 

Normally, an airplane will have two black boxes, located in the front and back of the airplane. One near the tail part of the aircraft, and another one in the cockpit where the pilots are at.

The black box comes in two parts which are the Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR). The FDRs record 88 values about the operation of the aircraft for about 25 hours while the Cockpit Voice Recorders will record 2 hours of all the sounds on the airplane.

black box

The black box is not black

When you hear the term black box, obviously, you will have the idea that this instrument is black. However, this ‘black box’ usually comes in orange or other bright colors. Painting the flight data recorder orange will make it easier to locate if needed.

There are many theories on why these devices are called the black box. One is that the inside of the box in the early design was completely black. Another theory is that the journalists wrote about the flight data recorder as the “wonderful black box”, due to the fact that they saw the charring from the fire on the outside of the boxes.

The black box is indestructible

You might wonder how can the FDR (Flight Data Recorder) survive the crash when something even bigger and looks even stronger like the aircraft itself could not. The answer is that the FDRs are made of one of the most durable and strongest materials, which is titanium.

The black box is heavily protected, made of titanium and stored in a titanium box. This makes it almost impossible to destroy or damage. A black box can survive any condition no matter where it was dropped and is able to work for 30 days without any electricity.

The titanium box helps protect the FDRs tremendously. It can withstand the fall to concrete floor at 750 km/h, water pressure of 6,000 meters depths, and even survive temperatures up to 1,100 degree Celsius for one hour.

What is Recorded in the Black Box?

As mentioned, there are two parts of the recorded data, the 88 values of the information about the aircraft operation and the recorded voice.

The 88 data from the FDRs include location, speed, turbulence, cabin temperature, pressure altitude, and many more. The flight data recorder will record 25 hours worth of data, and keep recording over itself after 25 hours. 

Here are the example lists of the data recorded on the Flight Data Recorders:

  • Date and Time
  • Pressure altitude
  • Airspeed
  • Fuel flow
  • Rudder-pedal position
  • Control-wheel position
  • Horizontal stabilizer
  • Vertical acceleration
  • Control-column position

Another part is the cockpit voice recorder that will record every sound on the aircraft in both the cockpit and cabin including the conversations, crews’ interactions, air traffic control, as well as, the background noises like the noises from the seats, machines, and even objects dropped. 

These days, only the last two hours or about 120 minutes of the sounds will be recorded. The recording will record the sound over itself in a loop.  However, the older version of cockpit voice recorders can only record the voice for 30 minutes. 

black box

How Can the Investigators Locate the Black Box?

Do you ever wonder how the investigators can locate the black box since it might have fallen far away from the crash site or when it dropped in the ocean? We have the answer for you in this article.

The black box is designed and developed to be easy to find everywhere. First of all, bright colors like red and orange are used to make the boxes stand out from the surroundings, even at night. 

As mentioned earlier in the article, the black box can work for 30 days without electricity, the function for these 30 days is to emit the beep sound for 30 days straight. This will make the investigation team locate the black box easily and faster. The beep sound from the black box is loud enough to be heard from 2-3 km away. 

And for the black box that has fallen into the ocean, the black box will emit the waves as well as the beep too. It can emit the waves or the signal when it comes into contact with saltwater and can emit the waves even being at 140,000 depth in the sea. These waves can be spotted within a radius of 2-3 km, making the investigation team pinpoint the plane wreck easily.

How does the Recorded Data help the Investigation?

The information recorded in the flight data recorder will be used to determine the cause of the crash by reconstructing the situation and events in the aircraft in every aspect before the crash happens. The data about the airspeed, pressure altitude, fuel flow, and many more will be used to predict and simulate what happens to the aircraft, and what causes the fall. 

As well as the sounds from the cockpit and the cabin will be listened to and find clues to what happened before the plane crashes. The little sounds that you might not think will matter, like the sound of the pushed-back seat, can tell the investigators that the pilot had left the seat and the cockpit before the crash. 

Final Thoughts

A black box or the flight data recorder is the most important instrument that helps the investigators find out what happened in the plane crash. The result and answers obtained from reconstructing the incident with data from the black box can help put the mind of the family and friends of the victims of each plane crash incident.

Subscribe !

free and exclusive

Articles on aviation