But many aviation experts wonder why, in our increasingly networked world, divers are scouring the Indian Ocean for a metal box when technology already exists that would enable planes to stream black box data to the ground in the event of an emergency.
"Look at how much money has been spent, on this crash and others, just to do the post-mortem," says Doug Perovic, a professor of materials science and engineering at the University of Toronto.
"It's crazy, when the technology [to stream the data] is already there."
By some estimates, it would have cost just a few thousand dollars in satellite time if MH370's black box had been primed to live-stream its data over the estimated seven hours that followed that first dramatic veering off course.
Black boxes have been on planes since the late 1950s, and now every commercial aircraft has two: a flight data recorder (FDR) and a voice recorder. (Although they are referred to as black boxes, they are typically orange in colour, making them easier to spot in murky waters.)
According to standards set by the U.S. Federal Aviation Administration, the FDR must contain a minimum of 88 data "parameters" on the flight conditions of an aircraft, from time of day to altitude, air speed and acceleration.
Housed in a metal shell built to withstand extreme temperatures and pressure, black box recorders are mainly used to investigate the cause of in-flight accidents.
While black boxes are built to survive a crash and long-term submersion in water, they also have a built-in design flaw – if a plane has gone down in the ocean, it can be an enormous challenge to find the device. While each box contains a beacon, the unit only has enough battery power to transmit a signal for 30 days.
After the crash of Air France Flight 447 in the Atlantic Ocean in June 2009, it took divers two years to find the black box.
Technology in place now
The disappearance of the Malaysian Airlines flight, and the thwarted efforts thus far to locate its black boxes, has led some aviation experts to doubt their usefulness.
Pierre Jiennot, a Canadian engineer who helped perfect black box technology while working at Air Canada about 40 years ago, feels that the device, in its current form, is "obsolete."
He started to question its effectiveness more than a decade ago, after seeing the extent of the plane wreckage in the 2001 attacks on the World Trade towers in New York.
"The black boxes were pulverized," he says. He thought back then that it would be far more efficient to be able to transmit that flight data to the ground.
"It seemed obvious to me that we could have had the information piped through a satellite instead of having to … look for a black box," says Jiennot, who is now on the advisory board of Star Navigation Systems Group, a Toronto-based firm that has built a live-streamed black box system.
Calgary-based FLYHT Aerospace Solutions sells a similar system. Called the Automated Flight Information Reporting System (AFIRS), FLYHT's product combines the infrastructure of the internet and the constellation of 66 satellites operated by Virginia-based Iridium Communications.
When a plane experiences an adverse event, AFIRS can send streaming data off the aircraft to one of Iridium's 66 satellites and then down to ground-based servers, where the message is interpreted and sent to the airline.
The infrastructure for this type of system has existed since about 2000, but it wasn't until after the Air France crash that airlines took it seriously, says Richard Hayden, sales director for FLYHT.
"The loss of one of the most sophisticated aircraft in the sky in 2009 [the Airbus A330-203 in the Air France flight from Brazil] basically woke people up to the fact that the tools that were being used at that stage were inadequate for dealing with emergency situations," says Hayden.
Even so, he notes, "aviation doesn't move very quickly to adopt change."
Because of ever-present safety concerns, the industry is highly regulated and new technology is subject to rigorous vetting.
"Some of that inherent caution and conservatism is why airplanes are so safe," Hayden says.
The cost factor
While there is widespread approval of a live-streamed black box system, most airlines see the cost of integrating it prohibitive, says Bill Norwood, vice-president of products and technology for JDA Aviation Technology Solutions, a Maryland-based consultancy firm.
Norwood says that the airline industry is reticent to add costs that will further erode the bottom line. This is an industry with notoriously low profit margins, he says.
According to The Economist magazine, airlines have average profit margins of just one per cent, and in 2012, "they made profits of only $4 for every passenger carried." This is largely due to the cost of fuel and government fees.
Norwood says the chief cost in using a live-streamed black box system is transmitting the data through satellites, which will have a direct bearing on the cost of every flight.
"In the realm of making the flight profitable or not profitable, if they start [live-streaming black box data], the flight is no longer profitable," he says.
That view reflects a lack of understanding about what the technology is capable of, says Hayden, who adds that FLYHT has sold 350 units of its AFIRS system and has orders for 250 more.
He says the AFIRS system doesn't stream black box data for every hour of every flight. It only begins streaming data once an irregular event has occurred, which reduces the satellite transmission costs significantly.
Hayden says that based on Iridium's pricing, it would cost about $5 to $7 US per minute to transmit black box data via their satellites to the ground.
He estimates that if this technology had been on board the missing Malaysian Airlines flight and live-streaming for the estimated seven hours after the flight first experienced a problem, it would have cost about $3,000.
Given how much time, money and effort has been expended on the luckless search for MH370's black box, the cost of operating a live-streaming version seems like a trifle, says U of T's Perovic.
"I don't think it's a prohibitive cost, particularly with something where the risk factors are high."
Mystery of Malaysia Flight 370
Tune in Sunday, March 30 at 10 p.m. ET/PT to The Passionate Eye on CBC News Network for a documentary that unravels the theories and probes the mysterious disappearance of Flight MH370.