What Are Black Boxes and How Do They Function?

When discussing aircraft and their standard equipment pieces, most people would recognize the black box. As the term reaches public ears most often during the discussion of aviation accidents, many have strong negative associations with such devices. Despite their grand importance during accident investigations, black boxes serve a great role in improving the safety of flight and aircraft operations. To best understand how black boxes benefit the aviation industry, one first must be aware of their functionality and capabilities.

While many refer to such devices as a “black box”, this is simply a nickname given to such equipment. Within the aviation industry, many individuals use the more technical name which is to call such equipment an “electronic flight data recorder”. Depending on the aircraft in question and the various jurisdictions it falls under, an electronic flight data recorder may refer to either a cockpit voice recorder (CVR), flight data recorder (FDR), or a combination of the two in one system. For safety, most aircraft are required to have two separate systems to ensure redundancy in the case of a failure or issue.

The flight data recorder is a device that is capable of recording any instructions that are transferred to aircraft electronic systems. With modern devices, an average of 700 different parameters can be captured for later analysis despite some federal regulations requiring much less, such as 88 parameters in the United States. Additionally, many FDRs are capable of recording upwards of 25 hours of data in a continuous loop, meaning that new information will consistently replace the oldest information when space becomes limited. As analyzing information can often be a complex procedure when investigations are conducted, most current aircraft models will provide pilots with an event button that can mark a time in the FDR when abnormal occurrences happen.

With a cockpit voice recorder, on the other hand, recordings will consist of any captured audio from the aircraft flight deck. With devices commonly featuring 4 channels of audio data and 2 hours of capacity, pilot headset microphone and earphone audio is captured alongside noises within the cockpit such as radio transmissions, automated alarms, and pilot conversations. While cockpit voice recorders were a later addition to black box devices, they have been crucial for many investigations as they can provide information on what was occurring in the cockpit at the time of an incident and how pilots were reacting to such situations.

With the various black box technologies available and required for aircraft, investigators can reconstruct the situations leading up to an accident or downing, allowing them to increase the safety of aircraft to avoid similar situations in the future. While black boxes have the nickname that they do, almost every single device is painted a very bright international orange color. This is due to the fact that black boxes are designed to stand out and be easily retrievable by accident investigators. This is extremely important when an accident occurs in remote areas of the ocean, as spotting an orange device can be much easier.

Beyond the coloring of the device, black boxes also contain underwater locator beacons that are designed to begin emitting signals once the device has come into contact with water. With a battery charge to last about a month, the underwater locator beacon will continue transmissions until losing charge. As remote stretches of ocean can be very difficult to search when you do not have a precise location, many have called for improvements to the beacon to ensure stronger signals for easier search expeditions.

As black boxes are critical to accident investigation, such equipment pieces are designed to be extremely robust so that they may survive many different environments for a long period of time. To test that black boxes are fairly indestructible, they are often launched straight into a concrete wall at 750 kilometers an hour to simulate the most catastrophic crashes. In addition to wall tests, the black box will also be tested for its ability to withstand up to 2.25 tons of pressure for five minutes, survive an hour in temperatures reaching 1,100 degrees Celsius, and continue to function underwater at extreme depths.

In order to achieve the near-indestructible qualities required for surviving the harshest conditions, black boxes have their components sheathed in a multi-layer protective shell. For the key components of the device, the power supply, memory circuits, and controller board are all separated into individual units so that each module may be removed and replaced as necessary without disassembling the entire device. As the memory unit is considered the most important part of the assembly, it is placed within multi-layer protection consisting of steel armor plate housing, insulation, and a thermal block to ensure that the temperature at the core is always safe. With a variety of mounting shelves, insulating layers, and heavy metal plating spread throughout the device, all components within the black box can be better protected.

As we move into the future, many manufacturers are experimenting with new technologies to improve aircraft accident investigation. For example, flight recorder manufacturer Smith Industries has already begun development for a device that is known as an Integrated Data Acquisition Recorder (IDAR). As a single device, the IDAR would fully replace the FDR and CVR, allowing for flight parameters and voice data to all be transferable through data transfer systems. Also featuring reduced weight, such devices can prove to be the future of black boxes. As more legislation continues and more parameters become required, many manufacturers may soon join in development with new technologies to improve aircraft safety.

With black box technology, the aviation industry can continue its mission to increase safety for the benefit of all who travel across the skies. At Aviation Store Online, we are a premier online distributor of aviation parts with an unrivaled inventory of over 2 billion items. We invite you to peruse our offered listings at your leisure, and you may request a quote at any time for items you are interested in through the submission of an Instant RFQ form. Begin the part procurement process today and experience how Aviation Store Online can fulfill all your operational needs with ease.


October 12, 2022

Recent Twitter Posts

Semiconductor's Certifications and Memberships

The only independent
distributor with a
  • All Orders are Fulfilled in the U.S.A.
  • All shipments must comply with U.S.A export laws.
  • No exceptions.
Intrepid Fallen Heroes Fund

“We Proudly Support Intrepid Fallen Heroes Fund that serves United States Military Personal experiencing the Invisible Wounds of War : Traumatic Brain Injury (TBI) and Post Traumatic Stress (PTS). Please visit website (www.fallenheroesfund.org) and help in their valiant effort”.

Thank You for Visiting Us today!

We Hope You'll Remember Us the Next Time If You’re Looking for Aircraft Parts.

Request for Quote

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.