In the event of a plane crash, a lot of people have a lot of questions running through their minds. Experts and aviation authorities often rely on Flight Data Recorders (FDR also commonly called black boxes) to answer these questions. However, when a plane ends up in the water, we’re always faced with an important question: “Do black boxes float?”
Black boxes don’t float due to their high-density constructions, which have to withstand extreme forces in the event of a crash. To find a sunken black box, most black boxes are equipped with an Underwater Locator Beacon (ULB). Alternatives to floating black boxes are being investigated, including real-time cloud data streaming.
Many people consider this fact quite disturbing. And they may be right to think so. If we rely so much on black boxes to get all the information we need after a tragic flight, we don’t really want them underwater where they may be harder to find. The aviation industry is filled with so many smart minds who work hard continuously to make flying safer. So, one begins to wonder why black boxes haven’t advanced so much as to fit each plane with one that floats.
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Top Reasons Why the Majority of Black Boxes Don’t Float
The main reason why most black boxes don’t float is closely related to their engineering. Due to the extreme circumstances black boxes are built to withstand, they are highly regulated by the International Civil Aviation Organization (ICAO). These regulations often require that they meet certain crashworthiness and fire protection specifications.
Some of these requirements include:
- Heat/Fire (High Intensity): More often than not, planes explode when they crash. This leads to the industry’s demand for all black boxes to be able to withstand very high temperatures. They are hereby tested in a flame (at a temperature of 1100°C) fully submerging them for either 30 or 60 minutes.
- Heat (Low Intensity): Black boxes also undergo an oven test under 260°C for a more prolonged period of 10 hours.
- Impact shock and static crush: Black boxes should withstand 3,400 Gs for 6.5 milliseconds and 5,000 pounds for a duration of 5 minutes on each axis.
Looking at these above-listed requirements, one thing becomes clear. Any device that can withstand such conditions must be pretty dense.
Typically, black boxes are made nearly indestructible by protecting the working components with a multi-layer protective shell. These layers are often made up of materials like aluminum, stainless steel, and or titanium. What we get in the end is a device with a density higher than that of water.
But aside their engineering, there’s also another logic behind the inability of black boxes to float.
The major problem with black boxes that float is that they may be significantly more difficult to locate. A floating black box will easily drift away from the spot of the crash making it harder to find.
In many recent air crash cases, most black boxes are found despite sinking deep underwater. Nonetheless, a couple of airplanes are fitted with black boxes that float. These are mostly military aircraft.
Retrieving Information Underwater
So, if black boxes don’t float, how then do we access the information they hold after they go underwater?
First of all, it is important to note that black boxes aren’t built to record information only. Of what use is the recorder if it can’t be found after an accident after all?
This is why a flight recorder is equipped with an Underwater Locator Beacon (ULB). In the industry, this beacon is informally referred to as a pinger. Once a black box is immersed in water, the pinger is immediately activated. The search personnel can then use a special receiver to locate the black box. A pinger can transmit signals from depths as low as 14,000 ft (4.2km) underwater.
When the black box is found, it is quickly immersed in freshwater. This is necessary to undo the corrosive effect of saltwater. Saltwater is highly corrosive and easily depletes stainless steel which is normally waterproof. Though black boxes can survive long exposures to saltwater (two years or even longer as in the case of Malaysia Airlines Flight 370), they won’t hold out forever. Drying the black box immediately after retrieval will actually cause more damage as saltwater becomes more corrosive at higher concentrations.
Now that the black box is salt-free, it is then opened carefully and dried properly. Technicians at the laboratory can now download the stored data into their special computers and access the information.
The Cost of Floating Black Boxes
As earlier mentioned, some aircraft are actually equipped with black boxes that float. This kind of engineering is not common to date for valid reasons. Being able to achieve a low density while meeting all the ICAO requirements always comes at a relatively high cost. Such black boxes are generally known as deployable and have been in use by the US Navy since 1993. With civil aviation in mind, it was estimated that a single unit of a deployable black box will cost $60,000.
But here’s the catch—the unit is also equipped with satellite technology enabling immediate location of the crash site.
In March of 2014, a US House lawmaker, Rep. David Price called for the implementation of a “deployability” requirement for all black boxes in all commercial aircraft. This call came in the wake of the Malaysia Airlines Flight 370 search. Price argued that the government could provide funding in partnership with the manufacturers and airlines who were reluctant to bear the cost implications. Considering that the Transportation Security Administration received $3.5m in 2008 to study a similar proposal, the likelihood of implementation in the near future is still open to debate.
The Future of Black Boxes: Will They Float?
Discussions concerning the future of black boxes are generally charted in 3 directions. Black boxes may take either or several of these forms in the future:
- Black boxes that can be ejected.
- Black boxes that float.
- No black boxes at all.
The most interesting of these options is the last. In fact, the idea of completely doing away with the physical black box is now at the center of the race for the next-generation black box.
The concept is to be able to stream vital information from the aircraft to remote cloud storage in real-time. In a time when wireless connectivity is achievable on mobile phones and even in the plane mid-air, this appears to be a very easy task. But in aviation, safety parameters may make things more complicated than they seem.
One of the companies at the forefront of developing this cloud-to-cloud model is Honeywell. In collaboration with Curtiss-Wright, they believe a new cloud-based device should be available for use by August 2020. But a Canadian company, FLYHT Aerospace Solutions seems to be even ahead of the curve. As of 2016, they were already installing a black box streaming service on their partner’s planes for a whopping sum of $100,000 per plane (hardware included). At the time, they had installed this service in about 400 planes for over 50 customers—one of which was Canada’s First Air. But their approach to streaming data is different. The system only activates when it detects an anomaly. It then quickly sends huge chunks of data to the airline where it is analyzed.
Ending Words
In a nutshell, black boxes may not be improving as fast as the other components of an airplane. However, while the majority of them do not float now, we might be looking at a safer future where we no longer need physical black boxes anymore.
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