Inside the Black Box

Inside the Black Box

What is the Black Box?

The black box (which isn’t actually black), or flight data recorder is an electronic device placed inside aircraft to automatically document all manners of information from the flight, from speed and position to the settings on the flaps and trim.

There are two types of black boxes. The flight data recorder tracks all the physical information, while the cockpit voice recorder collects audio data from the flight deck, so investigators can piece together what transpired in the events of an accident. Black boxes are designed to be nearly indestructible, in accordance with ICAO regulations. They are made to withstand long periods of temperatures of 1,000 °C (1,830 °F) or more, and impacts of 3400gs (for referencing, sitting on your couch, you’re subject to 1g of atmospheric pressure).

A History of Black Boxes

The “Flight Recorder,” as it was listed on the filing, was invented and patented in the United States by Professor James J. “Crash” Ryan, a professor of mechanical engineering at the University of Minnesota in 1960. Ryan also invented the retractable seatbelt, which has saved an estimated 375,000 lives in the US alone. He invented the first crash survivable data recorder alongside General Mills’s (yup, the food giant) mechanical division. It recorded basic things, like altitude and speed, but with high levels of accuracy.

Simultaneously, David Warren at the Defence Science and Technology Group in Melbourne, Australia, was working on a similar design, which included a voice recording aspect. However, it has limited success with crash survivability until it was redesigned and relocated in 1965, after Professor Ryan in the United States had filed his patent.

Before Professor Ryan patented the modern flight data recorder, its earliest iterations date back to François Hussenot and Paul Beaudouin in 1939. Unlike modern black boxes, which use digital memory, their system worked by projecting data onto strips of film using a light-sensitive mechanism. This device was known as the “hussenographe.”


The Modern Flight Data Recorder

There are 88 parameters required to be collected as a minimum under current US federal regulations. This includes a wide scope of aircraft data, including from the engines and flight control surfaces. Generally each parameter is recorded a few times per second. They’re made of corrosion resistant materials, capable of withstanding the harsh depths of the ocean or the impact of a 500mph crash. FDRs are also equipped with locator beacons, which beam continuously for up to 30 days and can function at a depth up to 20,000 feet beneath the water’s surface.

After a crash, the flight data recorder is one of the most critical components in determining how and why the accident occurred, especially if nobody from onboard survives.


Sources and Further Reading

FlightLine Weekly
Minnesota Public Radio News
National Transportation Safety Board
USA Today
Honeywell Aerospace
AIRBUS
HistoryNet
Image Credit

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So it would be bust at the bottom of the Mariana Trench.

In all seriousness - great article as always Mort - amazing job!

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Yep. Hopefully there’s never a situation where a plane goes down there.

Thank you!

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