الثلاثاء، 8 يناير 2013


The End of the Black Box: There’s a Better Way to Capture Plane Crash Data

The black boxes were sitting on the ocean floor in what would have been plain sight, if there were any light at a depth of 12,800 feet. They were guarded by silent corpses, the passengers and crew of an Airbus A330 that plummeted to the bottom of the Atlantic in June 2009. For nearly two years, the boxes—not black, actually, but bright orange—had lain amid some of the most rugged undersea terrain in the world, 11,500-foot mountains rising from the ocean floor, covered with landslides and steep scarps. Until the days in May when an advanced robotic submersible, the Remora 6000, brought the two black boxes from Air France flight 447 to the surface, they were among the world’s most sought-after artifacts, the keys to understanding why a state-of-the-art widebody jet fell out of the sky on a routine flight from Rio de Janeiro to Paris, killing all 228 aboard. Since no one knew the exact coordinates of the crash, the searchers had to extrapolate their grid from the plane’s last known location. It took a team led by the king of undersea searchers, Dave Gallo of the Woods Hole Oceanographic Institution, to find the wreckage; Phoenix International, a deepwater recovery company, finally brought the recorders home. Why did it take so long? “You can find a needle in a haystack,” Gallo says, “but you have to find the haystack first.”
French accident investigators removed the memory cards, carefully dried them, plugged in the right cables, and soon announced that the boxes had preserved nearly all the data they had captured—two hours of audio recorded from the cockpit and a complete record of thousands of measurements taken between takeoff and the moment the Airbus crashed. It was regarded, rightly, as a technological triumph. Although voice and data recorders are built to withstand the most extreme conditions of shock, fire, and pressure—they get fired from an air cannon as part of the testing regimen—they are not designed to preserve data for so long at such depths. The black boxes, built by Honeywell, had greatly exceeded their specifications.
But this elaborate and expensive undersea search could have been avoided; the technology has long existed that could make the recorders obsolete. As the BEA, the French agency that investigates air accidents, struggled to explain the crash in two inconclusive interim reports in 2009, the question was already being asked: If real-time stock quotes can be transmitted to anyone with a smartphone, why does the vital work of investigating an airplane crash still depend on reading physical memory chips that must be rescued from the wreckage?
The tragedy of Air France 447 might have been on the minds of executives from Bombardier, the Canadian aircraft manufacturer, when they announced in 2010 that their new CSeries narrow-body jets, scheduled to come to market in 2013, would be the first commercial airliners built with the capability to transmit telemetry data instead of merely recording it. The idea—to stream black box data in real time, either directly to a ground station or by satellite relay—isn’t new, even though there remains no consensus on whether to call it an uplink, which is conceptually accurate, or a downlink, which expresses the physical relationship of an airplane to the ground.
Bombardier is advertising the innovation not as a way to improve crash investigation—survivability of data after a crash isn’t something airplane manufacturers like to boast about—but as a way to give airlines a central database for routine information on airplane operations and mechanical performance. At a minimum, the data could be stored securely as a backup to black boxes in the event of an accident. One company, Calgary-based FLYHT AeroMechanical Services, already provides this service as an aftermarket retrofit; so far, smaller carriers and charters have been the main customers.
But until the Air France crash, streaming data was mostly considered a solution in search of a problem. Black boxes were almost always found: The last US or European accident from which onboard data recorders were not recovered was the World Trade Center attacks, in which both planes were essentially vaporized. When planes crash into the ocean, locator beacons on the black boxes send out an ultrasonic ping designed to be heard through the water at distances of up to several miles. “Approach and landing accidents are half the crashes in a given year,” says Bill Voss, president and CEO of the Flight Safety Foundation, “and then you just walk over and pick it up.” Even in the more difficult cases, black boxes usually survive. Data was retrieved from the recorders aboard the hijacked United Airlines flight 93, which nosed into a Pennsylvania field on 9/11 at an estimated speed of over 550 miles an hour, gouging a crater 8 feet deep.
Invented in the 1950s after a spate of accidents involving the de Havilland Comet, the first commercial jet, flight data recorders have become standard equipment on all but the smallest aircraft. The earliest models recorded data with a moving stylus on a roll of foil; as recently as 1994, when USAir flight 427 rolled over and crashed on approach to Pittsburgh, the flight data recorder on the Boeing 737 measured only 13 parameters, such as altitude, airspeed, heading, pitch and roll, and whether the pilots were pulling or pushing on the control column. It did not, for instance, record the position of the rudder or of the rudder pedals in the cockpit—information that turned out to be crucial in the investigation, which took five years before probable cause was ascribed to a malfunction in the rudder’s hydraulic control valve.
As a result, the latest black boxes are far more sophisticated. The FAA requires most planes flying today to monitor only 88 parameters, generally once or twice per second, but data recorders on modern commercial jetliners may track as many as 3,000 data points, including the status of every system on the aircraft, the positions of cockpit controls, and pressure and temperature readings from fuel tanks and hydraulic systems. Sensors monitor every point in the engines from intake to exhaust. And starting next year, new rules will require that critical measurements such as the positions of flaps, ailerons, and rudders get sampled eight times per second. Some airlines use this data for routine purposes like scheduling engine maintenance, but you never know what might turn out to be important in a crash investigation. It is, of course, far more information than is available to pilots in the cockpit—or that they could possibly absorb during a crisis. When something goes wrong at 550 miles an hour, it can go wrong very quickly.

Black Box
The "Black Box" Voice-plus-Data Recorder is the invention attributed to Dr David Warren of what was then known as the Aeronautical Research Laboratories (ARL) at Fishermans Bend, Melbourne, Australia. At the time of the invention, ARL was part of the Commonwealth of Australia's Department of Supply - ARL later became part of the Defence Science and Technology Organisation (DSTO), part of Australia's Department of Defence.
Dr Warren's work was first published in 1954 (Black Box Ref. 1 below). My involvement peaked around 1961 when the development of a pre-production prototype of airborne recording and ground station recovery equipment was undertaken prior to in-flight testing. This was the first time I met David Warren and found him then to be an inspirational scientist well capable of "thinking outside the box". Our friendship has endured through the years.
My involvement, together with that of other scientific staff (Lane Sear and Walter Boswell, both deceased) aimed to update the early model Flight Memory system pioneered by Dr Warren (who died in July 2010) to a pre-production standard, suitable for recording cockpit voice and instrument readings on a crash-survivable medium. Airborne and associated ground recovery instrumentation was developed for in-flight demonstration purposes. The pre-production prototype was installed in the Department of Civil Aviation Fokker Friendship aircraft, VH-CAV, and the maiden test flight took place on 23 March 1962 departing from Essendon airport (in Melbourne, Australia). Recording and recovery of cockpit voice and flight data was 100% successful. In anticipation of the coming mandatory requirement, the British firm of S. Davall & Son approached ARL for the production rights and their "Red Egg" crash recorder was developed from it, winning a large part of the British and overseas market at that time.
Dr Warren, together with the team involved in the pre-production prototype development, were recognized in the Lawrence Hargrave Award granted by the Australian Division of The Royal Aeronautical Society in February 2001 (almost 40 years after the successful flight demonstration occurred). The award was presented by The Hon John Anderson MP, who was the Australian Minister for Transport at the time.
Apart from the Lawrence Hargrave Award mentioned above, Dr Warren has received a number of prestigious awards. In November 2000, he was awarded the Millenial Hartnett Medal from the Royal Society (Victoria Chapter) for the Encouragement of Arts, Manufacture and Commerce. In January 2002, he was appointed an Officer in the General Division of the Order of Australia for his "service to the aviation industry, particularly through the early conceptual work and prototype development of the black box flight data recorder".
My involvement in the Black Box development has been reported in my Publications 9, 10, 25 and 41. I still find it hard to comprehend that the work I did at about age 24 (my age at the time of the successful flight demonstration on the Fokker Friendship aircraft) is the item for which I have received most accolades.
Most of the Black Box hardware is held at the Scienceworks Museum, 2 Booker Street, Spotswood, Melbourne, Victoria 3015, Australia. The wire recorder is held at DSTO's Melbourne Laboratory, 506 Lorimer Street, Fishermans Bend, Victoria 3207, Australia.

الأحد، 6 يناير 2013

History of Flight Image Gallery
Photo courtesy U.S. Department of Defense
The cockpit voice recorder from the downed Alaska Airlines Flight 261, held by the robotic arm of the remotely piloted vehicle that retrieved it.  See more flight pictures.
On January 31, 2000, Alaska Airlines Flight 261 departed Puerto Vallarta, Mexico, heading for Seattle, WA, with a short stop scheduled in San Francisco, CA. Approximately one hour and 45 minutes into the flight, a problem was reported with the plane's stabilizer trim. After a 10-minute battle to keep the plane airborne, it plunged into the Pacific Ocean off the coast of California. All 88 people onboard were killed.
With any airplane crash, there are many unanswered questions as to what brought the plane down. Investigators turn to the airplane's flight data recorder (FDR) and cockpit voice recorder (CVR), also known as "black boxes," for answers. In Flight 261, the FDR contained 48 parameters of flight data, and the CVR recorded a little more than 30 minutes of conversation and other audible cockpit noises.
Following any airplane accident in the United States, safety investigators from the National Transportation Safety Board (NTSB) immediately begin searching for the aircraft's black boxes. These recording devices, which cost between $10,000 and $15,000 each, reveal details of the events immediately preceding the accident. In this article, we will look at the two types of black boxes, ­how they survive crashes, and how they are retrieved and analyzed.

Flight Data Recorders
The flight data recorder (FDR) is designed to record the operating data from the plane's systems. There are sensors that are wired from various areas on the plane to the flight-data acquisition unit, which is wired to the FDR. When a switch is turned on or off, that operation is recorded by the FDR.

Photo courtesy National Transportation Safety Board (NTSB)
The damaged flight data recorder from EgyptAir Flight 990
In the United States, the Federal Aviation Administration (FAA) requires that commercial airlines record a minimum of 11 to 29 parameters, depending on the size of the aircraft. Magnetic-tape recorders have the potential to record up to 100 parameters. Solid-state FDRs can record more than 700 parameters. On July 17, 1997, the FAA issued a Code of Federal Regulations that requires the recording of at least 88 parameters on aircraft manufactured after August 19, 2002.
Here are a few of the parameters recorded by most FDRs:
  • Time
  • Pressure altitude
  • Airspeed
  • Vertical acceleration
  • Magnetic heading
  • Control-column position
  • Rudder-pedal position
  • Control-wheel position
  • Horizontal stabilizer
  • Fuel flow
Solid-state recorders can track more parameters than magnetic tape because they allow for a faster data flow. Solid-state FDRs can store up to 25 hours of flight data. Each additional parameter that is recorded by the FDR gives investigators one more clue about the cause of an accident.