A black box is a flight data recorder that must be in every air vehicle. All flight information is recorded in the black box with a specific algorithm. This makes the recorded flight data accessible to authorities when needed.
Contrary to popular belief, the black box is mostly bright orange, not black. Black boxes that are resistant to the most extreme situations are one of the most special tools of the aviation research industry with their voice recording features.
An airplane generally houses two black boxes, one at the front and another at the back of the aircraft. It records all the communication that takes place in a cockpit and does more than just that.
Black Box is made of Titanium metal and is enclosed in a Titanium box which gives it the strength to withstand any shock if it falls into the sea or falls from a height.
So it’s vital for authorities during investigation just like for the Yeti Plane crash in Pokhara a few days back.
History of Black Box
In view of the increasing incidences of airplane crashes, it was thought to develop a device that can give information about the reasons for Plane accidents and might also help in saving planes from accidents. Hence, a black box was invented.
Earlier the box was red in color and hence the name ‘Red Egg’. The inner walls of the box were black in color, so it came to be known as a ‘Black Box’.
The Black Box has two separate boxes:
1. Flight Data Recorder: This box can contain information about direction, altitude, fuel, speed, turbulence, cabin temperature, etc. About 88 such values for about 25 hours can be recorded. This box can withstand a temperature of about 11000°C for one hour and a temperature of 260°C for 10 hours. These boxes are red or pink in color so they can be found easily.
2. Cockpit Voice Recorder: This box records the sound of the airplane during the last two hours. It records the sound of the engine, emergency alarm, cabin, and cockpit in order to predict the conditions of the plane before any accident occurred.
How does a Black Box work?
As we have already been told that the Black Box is made up of strong metal. It can work for 30 days without any electricity. It can withstand a temperature of 11000°C. When this box is lost anywhere, it keeps on emitting the waves along with a beep sound for about 30 days.
This voice can be identified by the investigators from a distance of about 2-3 Kilometers. An interesting fact with regard to the Black box is that it can emit waves from the depth of 14000 feet in the sea.
The black box helps to clarify the reasons for accidents and to find ways to prevent them. The first use of the device dates back to 1947. After 1958, it was mandatory to have them on board according to the rules set by the Civil Aeronautics Board.
The black box stores all kinds of information and conversations about the plane. Thanks to its sturdy design, it can be protected even under the hardest conditions. Passenger planes’ black boxes are able to send signals under the sea for 90 days. The black boxes, weighing an average of 5 kilos, activated as soon as they interact with the water and start sending signals. So any team looking for the location of a plane crash can even find it under the sea.
The pilots’ conversations are recorded in the black box. So the researchers can listen to the pilots’ last conversations. However, this does not apply to every black box. Some black boxes only record data about the plane, while others do both jobs.
Black boxes are subjected to many safety tests before they are mounted on aircraft. Only black boxes that can pass these safety tests are used in aircraft. Although the black box is not a new device, it still operates with the same principle today. The last 2 hours of conversations in the cockpit, together with the data from the last 25 hours of the aircraft, are recorded by this device.
How a Black Box can aid a Crash ?
After finding the black box of a plane after a crash, investigators take it to a lab and download the data from the recorders inside. They then work out how the crash might have taken place. The FDR can also be played on the recorder after connecting it to a readout system.
The complete reading and analysis might take weeks to months for the investigators. The data can also be exported through USB ports. If recorders have incurred some damage, then memory boards on them are removed and a new memory is installed and connected to a functional recorder to get it to work. To read the CVR, an expert team is brought. Often, the team comprises airline representatives, specialists, and others. They interpret words and sounds recorded by the CVR.
What are the data an airplane black box records ?
An airplane black box records far more than just the cockpit voice. The altitude of the aircraft, its elevation, fuel flow, time of communication, and more are recorded by the sturdily designed device. Find the list of what an airplane black box records below.
- Time
- Pressure altitude
- Airspeed
- Vertical acceleration
- Fuel flow
- Horizontal stabilizer
- Control-column position
- Rudder-pedal position
- Control-wheel position, and more.
Why black boxes can’t always provide the answers ?
These black box always have their limitations. Here, we will list some of the limitations a black box can have.
The voice recorder only captures the final two hours: A record of what went on in the cockpit would be a priceless tool for investigators trying to work out whether the plane was the victim of foul play or a mechanical fault. But it’s not that simple even if the black box is found.
The black box on the missing airliner – which it provided – only retains two hours of recording. That’s the length of time that regulations demand. The principle is in place because it is normally the last section of a flight that determines the cause of the crash. But in some case it might well be that the key events happened long before the actual crash.
The battery life is short: The black box sends out a ping – activated by immersion in water – that can be picked up by a microphone and a “signal analyser”. There’s another beacon – the emergency locator transmitter – which transmits a distress signal on impact. But these don’t work in water. Both the voice recorder and the data recorder have their own pinger. But there’s a problem – the battery of the pinger will only last for 30 days.
It is a small object to find: The black box is bolted into the tail of the aircraft to avoid damage in a head-on crash. It is small – about the size of a shoe box. Contrary to the name, it is bright orange. But it’s not easy to see it in the middle of the ocean. The search will aim to try to locate the wreckage before moving in to pinpoint the black box by picking up the ping. If the pinger has expired then other techniques – such as magnetic detection – are going to be necessary.
It doesn’t float: The box is made out of aluminium and designed to withstand massive impact, fierce fire or high pressure. That means it’s heavy – about 10kg for what is a small box – and will sink quickly. The Indian Ocean has very deep sections. The search area ranges between 1,150m (3,770ft) and 7,000m (23,000ft) deep, media reports suggest. So investigators will have to consider the prospect of it being out of reach of many sonar devices.
The pinger’s range is only a few miles: The signal can typically only be picked up a mile away. The aircraft really needs to be almost directly on top of the black boxes to hear the ping. There are also factors that may diminish the signal. Wreckage on the surface, or if the black boxes are submerged in mud or sediment on the seabed. But if the pinger is deep on the ocean floor navies have hydrophone technology that has a better chance of locating it than conventional detectors.The black box may be giving off pings from the ocean floor. But if those pings hit a layer of warmer or colder water above, the signal might be refracted or reflected.
Though a black box does not reflect a clear picture of plane accidents and in some of the accidental cases it could hardly be found but one fact is for sure that it plays an important role in the investigation of plane accidents.