As the search for information about the missing Malaysian Airlines Flight 370 continues, here are questions and answers about the black boxes searchers are looking for:
Q. What is a black box?
A. A black box is actually two separate boxlike components – a cockpit voice recorder and a flight data recorder. The cockpit voice recorder stores the last two hours of dialogue and other sounds in the cockpit, captured by a microphone, before a crash.
The flight data recorder captures information about the plane’s parameters, such as altitude, airspeed and heading, from several flight systems and the flight management computer. These parameters help investigators create a computer video reconstruction and visualize how the plane handled before it crashed.
Both of the black box components have devices known as underwater locator beacons, or “pingers,” that activate when the recorders come in contact with water. The pingers work like sonar to help investigators locate black boxes and, thus, recover information about the plane’s crash. Pingers can transmit data from as deep as 14,000 feet.
Q. Why is it called a black box?
A. Black boxes get their name from when they stored data on photographic film and were painted black to “fend off the stray rays of light” that might have ruined the data, according to the Institute of Electrical and Electronics Engineers. Today, black boxes store data on memory chips, so both components are painted bright orange to make them easier to find after a crash.
Q. Which planes have black boxes?
A. The Federal Aviation Administration requires all large commercial aircraft and some smaller commercial, corporate and private planes to have black boxes. Most black boxes are located near the tail of the plane, which is usually the last point of impact in a crash.
Representatives at Fort Wayne International Airport said that even though local planes have black boxes, they are not easily accessible for passengers to see.
Q. What do black boxes do in flight?
A. Black boxes do nothing to help the plane when it is in the air, but they help investigators learn what caused a crash.
Q. What is a black box’s role in the search for the missing Malaysian plane?
A. If investigators can find the black box for the missing Malaysian plane, they can get a better idea of what was happening in the cockpit and the plane’s flight systems before the crash, which can help them determine whether it was an accident or an intentional act.
Q. How durable are black boxes?
A. Black boxes are hailed as the most indestructible parts of an airplane. They’re wrapped in high-temperature insulation and then encased in a corrosion-resistant stainless steel or titanium shell. They can withstand temperatures up to 1,100 degrees Celsius for 30 minutes, according to the National Transportation Safety Board.
Scott Hamilton, director of Leeham Co., an aviation consulting company, told NPR he can’t remember an incident when both black box recorders were damaged to the extent that they could not produce any useful data. But there have been a few instances when no black boxes have been found after a crash, such as when an Eastern Air Lines Boeing 727 from Paraguay to Bolivia struck a mountain in 1985.
Q. Are searchers close to finding Flight 370’s black box?
A. Black boxes are battery-powered and are expected to last a minimum of 30 days. There’s a chance the boxes from Flight 370 could last longer than that, but if the pingers activated when the plane went missing March 8, they could run out of battery power any day now.
Even if pingers stop working, the data in the black boxes will still be saved. But it’s a race against time for investigators because when the black box recorders stop emitting pings, it will be harder – if not impossible – to find them in the ocean. But it has been done: In 2009, the black box was recovered from a depth of 10,000 feet in the Atlantic Ocean about 23 months after an Air France crash.
The Navy is using devices called towed pinger locators on the Ocean Shield, an Australian vessel, to listen for signals. Several instances of a pulse signal have been reported in Indian Ocean waters since April 5.
Q. Would real-time streaming of black box data help?
A. In response to the difficulty of recovering black boxes, the Guardian and other news organizations have called for the implementation of real-time streaming of black box data by satellite or radio transmission. The Guardian suggests installing a processor connected to black boxes to live-stream a limited portion of the most important data.
“A recent patent application filed by Boeing describes such a system, which specifies a limited data set including the precise location of the aircraft and the flight control inputs by the pilot or the automation system,” the Guardian said.
Elizabeth Isham Cory, external communications director for the FAA, issued a statement to The Journal Gazette that said live data-streaming is probably not technically feasible with frequency bandwidth and ground-based storage requirements for about 5,000 airplanes in U.S. airspace at any given time.
“The FAA continues to work with industry and our international partners on policy and guidance for advanced technologies that may be useful in aircraft accident investigations,” the statement said. “While recovering data from accidents is a high priority, the agency believes detecting, understanding and mitigating precursor events prior to accidents is equally important.”
Even so, companies such as Canada-based FLYHT Aerospace Solutions are working to help black boxes transmit information in real time. The company’s Automated Flight Information Reporting System uses the Internet and 66 satellites to communicate information from black boxes to the ground, Yahoo News says. It begins streaming data after an irregular event occurs on a plane, and the cost is between $5 to $7 a minute thereafter.
Richard Hayden, sales director for FLYHT, said that if the system had live-streamed for about seven hours after Flight 370’s transponder stopped emitting a signal, it would have cost about $3,000.