EgyptAir Flight 804: Clues to a Tragedy

Early last Thursday morning, May 19, EgyptAir Flight 804, an Airbus A320 carrying 56 passengers and 10 crew members, went down in the Mediterranean on its way from France's Charles De Gaulle International Airport to Cairo.  The plane apparently broke up in the air and there are no survivors.  Search parties have begun to recover pieces of the wreckage, and data transmitted from the plane suggests that a bomb might have caused the crash.  But a definitive conclusion about the cause will have to await the recovery of the flight data recorders, if they can be found.

Generally speaking, commercial aviation safety has been a spectacular success story.  If you drive to the airport, the risky part of your journey is over once you park the car.  But determined terrorists can evade security measures to bring a plane down, and no amount of design improvements can make a modern airliner 100% secure against attacks.  In the case of Flight 804, we are fortunate to have information transmitted by the Aircraft Communications Addressing and Reporting System (ACARS) that has provided material for early speculation about the cause of the crash.

Within a day, a number of sources provided news media with ACARS data transmitted for a period of about two minutes around the time of the crash.  Two indicators associated with windows on the right side of the cockpit and several smoke alarms went off.  An aviation expert cited in The Telegraph (UK) speculated that a bomb in or near the right side of the cockpit could have blown out a window, and the resulting cabin depressurization at cruising altitude would have caused condensation fog that can set off smoke alarms.  As the plane broke up, the ACARS system could have kept working, which explains the length of time between the initial transmission and when communication was lost.

ACARS has been helpful in investigating other crashes, such as the Malaysian Air Flight 370 that went down over the Indian Ocean on Mar. 8, 2014.  Although numerous pieces of that plane have been recovered in widely separated locations, the underwater search for the main body of the aircraft continues to this day. 

The part of the Mediterranean over which EgyptAir Flight 804 went down includes some of its deepest waters, over 3000 meters (more than a mile) deep.  So it will be a challenge to find the flight data recorders, especially if the search takes longer than 30 days, which is about as long as the recorder underwater locator beacons operate. 

The continuing mystery of the Malaysian Air Flight 370 crash led to calls for live streaming of flight-recorder data in addition to hard-copy logging on the plane, and in the ACARS data that was recovered for the EgyptAir flight, we see that even in the absence of regulations requiring such streaming, airlines have begun to take advantage of digital communications channels to transmit data that can be helpful both for maintenance and in case of a crash.  Other improvements that could be made to flight-recorder technology include automatic ejection and flotation, as is already done for recorders on military aircraft.  Instead of sinking with the plane, military flight recorders are ejected during the crash and automatically deploy flotation devices which makes them much easier to locate on the water's surface.  Since national governments usually bear the burden of paying for underwater searches, you would think that they would see the logic in offering to reimburse airlines for the additional expense of military-style flight recorders.  But logic isn't the only consideration in international politics.

If the flight recorders and cockpit voice recorders are recovered, the question of whether the crash was deliberate will probably resolve itself pretty quickly.  If it was indeed a deliberate act, the question then becomes one of criminal investigation, and the security at De Gaulle International Airport will come under scrutiny.  As long as airliners are flown by human beings, the trustworthiness of the pilots is an essential link in the security chain.  Assuming the pilots were not themselves part of a conspiracy, that leaves the possibility that someone planted a bomb somewhere in the cockpit.  While cockpits are now typically sealed off from the rest of the plane during flight, it's possible that maintenance workers or others can get into them while a plane is on the ground.  The Telegraph reported that the short stopover in France may not have allowed security personnel enough time to give the plane a thorough going-over before it took off for Cairo.

Whatever the cause of the crash turns out to be, we will learn something from it.  If it was mechanical failure, which seems unlikely but is still possible, it may affect all A320 Airbuses out there, but if there is such a problem it hasn't shown up more than once, apparently.  If, as seems more likely, there was a deliberate act of sabotage, the technique used by the saboteurs will have to be guarded against in the future. 

Either way, sixty-six lives have been lost in what was in all probability an avoidable tragedy.  Most of the time, the vastly complex systems of design engineering, maintenance, operations, and security for air travel work essentially perfectly, and when we get on a plane we don't usually give much thought to the question of whether we'll be getting off  under our own power or not.  But the price of such liberty is eternal vigilance, and I hope the lessons eventually learned from this tragedy make future ones even less likely.

Sources:  I referred to reports from CNN.com at http://www.cnn.com/2016/05/21/middleeast/egyptair-flight-804-main/ and The Telegraph (UK) at http://www.telegraph.co.uk/news/2016/05/21/egyptair-crash---smoke-detected-inside-the-aircraft-cabin-as-sea/, as well as the Wikipedia articles on Aircraft Communications and Addressing System, flight recorders, and Malaysia Airlines Flight 370.

ICAO To Airlines: Watch Where You're Going (Every 15 Minutes)

Once in a great while, I have the satisfaction of making a prediction or calling for a certain action in this blog, and then seeing the called-for event actually come to pass.  Last month, the International Civil Aviation Organization (ICAO) issued a new set of tracking requirements for airlines in participating countries, which means just about every airline that flies in more than one country.  While a formal vote on the requirements won't happen till later in the year, the slow-moving machinery of the United Nations—of which the ICAO is a part—has finally creaked into action.  So it may not be too much to hope that the kind of situation that has kept the destiny of Malaysia Flight 370 a mystery to this day can be avoided in the future, or at least that such incidents will produce data that will make the plane easier to find.

Flight 370, which disappeared a year ago March 8, was supposed to stay within range of ground-based tracking radars.  But when it veered way off course toward the open ocean for reasons that are still unknown, the limited-range ground radars lost contact with it, and an onboard satellite-tracking system was not working, possibly because it was intentionally disabled.  The upshot was that once the flight disappeared, investigators had to use some arcane technical tricks to estimate the flight's last known location, and the resulting poor accuracy and long gaps between known locations have left searchers stuck with many thousands of square miles of ocean to cover.  The plane may never be found.

Back in January, I blogged on this tragedy and noted that the U. S. National Transportation Safety Board (NTSB) was urging the Federal Aviation Administration (FAA) to adopt improved flight-location technology.  I also noted that while this move would help us to find international flights operated by US carriers, a truly international solution would have to await action by the ICAO, which has now begun to act.

As reported in a recent Associated Press article, the ICAO rules would require each airline to get location updates for all their flights every 15 minutes.  How they get the updates is up to the airlines.  Deep-pocketed operations such as Air France already have automatic satellite-location systems in place, and probably either already meet the requirements or can change their operations slightly to comply.  Less well-funded airlines can fall back on having their pilots look at their pocket GPS they mail-ordered from Walmart and use their shortwave radios to report their position.  Any way will do, says the ICAO, but you have to update your flight locations every 15 minutes.  If the rules are approved, this requirement will go into effect in 2016, which is by UN standards almost instantaneously. 

A second part of the ruling pertains to automatic flight-location technology, typically a satellite link.  By 2020, all new airplanes carrying more than 19 passengers will have to go into a minute-by-minute location transmission mode if an emergency occurs such as a steep dive or significant deviation from the flight plan.  The five-year delay from now would give airframe manufacturers and their customers time to ready the technology and the money to pay for it, respectively. 

By specifying in the 15-minute rule the desired outcome rather than the technology required to achieve it, the ICAO has done a clever thing.  Each airline can tailor its response to its own circumstances and adopt an approach that doesn't place an undue burden either on the flight crew or on the airline's budget for new equipment.  For reasons that are not clear, but may have to do with relationships between large avionics companies and the federal government, FAA rules tend to be much more prescriptive of exactly how certain goals are to be achieved technologically.  Historically, the FAA owned and operated much of the technology itself, so naturally the agency got in the habit of telling the airlines what matching equipment they needed.  But nowadays, the central-control model is pretty old-fashioned and is being superseded by distributed technologies that rely upon a combination of public, private, and open-source resources to work.  Safety-critical technologies are a breed apart, and a certain level of standardization and certification is reasonable.  But I wonder if things might move a little faster in domestic aviation technology if the FAA took a hint from the ICAO, and moved toward simply telling airlines what is to be achieved, and let the firms themselves figure out how to achieve it.

All this comes too late to help those on the ill-fated Flight 370, which is probably—but not for sure—somewhere at the bottom of the Indian Ocean.  The death of a loved one is always a tragedy, but there must be a special pain associated with not knowing anything about the person's final hours, and what mischance caused their demise.  Sooner or later, someone will probably find the wreckage, and if enough evidence can be recovered it may be possible to reconstruct what happened.  But in the meantime, I hope that the proposed new ICAO rules will make it much less likely that airlines will simply lose track of a plane while someone runs off with it, and can even prevent such incidents from occurring in the future.

Sources:  The article "Airlines move to better track their planes" by Scott Meyerowitz and David Koenig was carried by numerous newspapers, including the Deseret News on Mar. 3, 2015 at http://www.deseretnews.com/article/765669470/Airlines-move-to-better-track-planes-a-year-after-Flight-370.html.  My post "High Time for SatelliteTracking of All International Flights" appeared on Jan. 26, 2015.

High Time for Satellite Tracking of All International Flights

This coming March 8 will mark one year since Malaysia Airlines Flight 370 disappeared from radar en route from Kuala Lumpur to Beijing somewhere over the Indian Ocean.  The wreckage has never been found, although communications experts used some almost accidental satellite-transponder data to estimate the last known location of the plane.  At the time, I recall thinking that if I was an airline and owned a number of high-value mobile assets known as airliners, I would want some way of knowing where each one was every minute or so, anywhere in the world.   After all, the technology for tracking the much cheaper assets called semi-trailer trucks has been around for years.  The little white domes on truck cabs report minute-by-minute locations to a data center where operators can pay a monthly fee to any one of a number of firms to keep tabs on shipments, and truck drivers too, for that matter.  But there is no international requirement for airlines to do the same.

Last week, the U. S. National Transportation Safety Board (NTSB) waded in with a recommendation for all passenger airliners to be equipped with improved location technology.  The board admitted it was motivated partly by Flight 370's disappearance, and called both for improvements in in-flight tracking and in "black-box" technology. 

The in-flight tracking part seems to be pretty straightforward technologically.  It would operate more or less the same way as the truck-tracking system.  Every minute or so, a GPS receiver on the plane would send its location to a satellite in view, and the satellite would relay that information to a data center, where it would be logged and made available in the event of an incident of interest.  The only slightly tricky part would be identifying which satellite to use.  But there are already geostationary satellites in orbit such as Inmarsat which provide virtually world-wide coverage, and the missing bits of Earth near the poles could be made up for by linking to numerous low-earth-orbit satellites in polar orbits. 

The technology is not nearly so much a hurdle as the cost and the peculiar structure of international aviation regulations.  The NTSB's recommendations went to the U. S. Federal Aviation Administration, and if the FAA adopts them they will be obligatory for all U. S. airlines—but nobody else.  Because the U. S. operates only a fraction of international flights over large bodies of water where the technology would be most useful, the idea will not succeed without international cooperation, and that means the International Civil Aviation Organization, or ICAO.

The ICAO is a United Nations body in charge of international standards for, well, civil aviation, as you might expect.  As such, its rulings have no force of law in individual countries unless the countries' own aviation regulations require that its carriers follow ICAO rules as well, which most do.  It was a 2008 ICAO ruling, for example, that required all air traffic controllers and flight crew members involved in international flights to be proficient in English.  I'm rather surprised that it took until 2008, but after all, everything takes a while at the UN.

The question is whether and when the ICAO might follow the NTSB's lead if the NTSB prevails with the FAA to make international-flight GPS tracking mandatory.  Enough alphabet soup for you?  The whole process—from tragic accident to technical recommendations to changes in laws and regulations—is typical of how safety technology develops in coordination with regulations requiring its use.  And the regulatory part is particularly tricky when it involves spending money.  The requirement that pilots speak English can be met by changing hiring practices, but GPS tracking will involve both up-front and ongoing expenses for new hardware—which itself needs to be standardized somehow—and rental fees to the commercial firms that operate the satellite transponders used to convey the location data.  Fortunately, we are not talking about large bandwidths here—the equivalent of a single cellphone text message every minute or so would be sufficient.  But coordinating all this will take some doing, and coordination of any kind at the level of the ICAO is a challenging and slow-moving process at best.  If they took till only seven years ago to agree on a common language for radio communications from international flights, the ICAO isn't going to churn out new GPS-location rules overnight, you can be sure. 

The other part of the NTSB recommendations concerns the nature of the onboard flight data recorders.  Now that video cameras and recording equipment are so inexpensive, the NTSB says we should have cockpit video as well as audio recorders, and that controls for the entire system should be inaccessible from the cockpit.  (There is some suspicion that the radar-transponder system of Flight 370, which works only within range of ground-based tracking radars, was intentionally disabled by the pilot.)  Also, the NTSB floated the idea (so to speak) that the flight recorders should be housed in buoyant housings and ejected upon impact so that they can remain on the surface, where their radio signals could be more easily received than the limited-range and limited-time sonar emissions that the units currently send out underwater. 

All these are good ideas, and if the FAA adopts them they will make an already safe U. S. air-travel system even safer, or at least increase the likelihood of finding any flights that go down in deep water.  And the information from such accidents is always valuable in preventing the next one, whether it was caused by mechanical failure, human error, or evil intent.

Nevertheless, I am not going to be holding my breath until the ICAO follows suit.  You would think that the international carriers themselves would have adopted something similar to the truck-tracking systems years ago, but there may be a mentality in place that makes such a system seem unnecessary because of the vanishingly small number of incidents in which it would turn out to be useful.  But once GPS tracking for international flights is in place, I bet folks find other uses for it, for things like fuel-economy efforts and even weather tracking.  But first, the ICAO has to get in gear, so stay tuned.

Sources:  The article "NTSB:  Planes Should Have Technologies So They Can Be Found" by Joan Lowy of the Associate Press was carried by numerous outlets, including ABC News on Jan. 22 at http://abcnews.go.com/Politics/wireStory/ntsb-planes-technologies-found-28409934.  I also referred to Wikipedia articles on Malaysia Airlines Flight 370, Inmarsat, and the ICAO.

Addendum Feb. 1:  Edwin Doetzal wrote me on Jan. 31 as follows:

"Your analysis of MH370 contained a couple issues:
Airliners do often have SATCOM tracking 'like trucks'.  On MH370, this system was turned off along with the radio transponder.
ADS-B is the new satellite based air traffic control system that will replace the radio based air traffic control system and is already being implemented through efforts by NAVCanada and ICAO.
What is currently in discussion are new systems such as AFIRS that would stream amounts of data automatically or by trigger in an emergency as well as explosive jettisoned FDR/CVR units.  Knowing where an aircraft was is of course not enough without the detailed DAQ information that might explain why the emergency happened and what action was taken by the flight crew.  A truck's limited DAQ can be retrieved from the ditch.  Please be assured that an airliner is a much more sophisticated system than a truck.
It was somewhat troubling to see such an article on an 'engineering ethics' blog.  With respect, it would seem that you are speaking outside your professional scope.  A retraction would appear appropriate.
Regards,

Edwin Doetzel

Lay Person"

It was careless of me to imply that airliners had no such tracking systems, and I apologize
for leaving that impression.  In the space I had, I meant to concentrate not so much on the technology as on the international coordination that would be needed to implement it uniformly so that flights such as MH370 would not slip through the cracks.  My thanks to Mr. Doetzel for the correction.