May 20, 2016

TSG IntelBrief: The Crash of EgyptAir Flight MS804

• On May 19, EgyptAir Flight MS804, en route from Paris to Cairo, crashed in the Mediterranean Sea with 66 people on board

• The circumstances of the crash, a dramatic fall from cruising altitude with no bad weather or emergency call, strongly suggest catastrophic decompression from structural failure or, more likely, an onboard explosion

• Aviation is always a target of terrorism; both France and Egypt are recent targets of the Islamic State

• Missiles such as the BUK system that downed flight MH-17 over Ukraine remain a concern, but the more likely threat to civilian aviation is onboard explosives made possible by insider threats or systemic flaws in security measures.


For the second time in seven months, the world is wondering if terrorism may be responsible for the downing of a civilian passenger airplane—and for the second time, Egypt is among the parties to the tragic loss of life. There have so far been no credible claims of responsibility, and while officials from numerous countries have stated that terrorism is the likely culprit, there is no definitive cause for the crash. EgyptAir Flight MS804, bound for Cairo from Paris, dropped off radar contact and plunged into the Mediterranean Sea minutes after entering Egyptian airspace, killing all 66 on board. Search and rescue units have already found debris believed to be related to the crash.

While much of the speculation in the early hours following a crash tends to be skewed, or wrong altogether, several facts immediately point to catastrophic decompression from an onboard explosion as a likely cause. First, modern passenger jets at cruising altitude rarely have accidents that lead to a crash; perhaps 10% of accidents occur at cruising altitude, and in such cases, the cause is usually obvious. The Air France crash high over the Atlantic Ocean in June 2009 that killed all 228 people on board was the result of a stall at cruising altitude caused by icing over the pitot tube sensors when the jet flew into a storm with severe icing. By contrast, MS804 came down in clear weather.

Furthermore, the absence of a distress call suggests that whatever happened at 37,000 feet was of so abrupt that the pilots were either unable to grasp what was happening or overwhelmed by the centrifugal forces of a plane rapidly spinning and dropping. Short of a wing or tail flap falling off due to metal fatigue or poor maintenance, only an onboard explosion could cause enough damage and decompression to put a modern plane—especially one with a long safety record—into an immediate state of unrecoverable descent. A rogue pilot taking control of the plane is a less likely, but still possible, scenario; instances of deliberate crashes include the March 2015 crash of GermanWings Flight 9525 in the French Alps, and that of EgyptAir Flight 990 off the coast of Massachusetts in October 1999. 

Available flight and safety statistics related to civilian passenger aviation make early hypotheses less speculative than assumed. Add the fact that last October, the so-called Islamic State demonstrated its ability to bring down a civilian plane at altitude through a bomb smuggled by an employee into the cargo hold, and terrorism becomes the likely cause even as other causes remain possible. 

If terrorism is, in fact, responsible for the crash of MS804, it is serious cause for concern. The flight originated in Paris—not Egypt, where security was breached in October—so it is not a repeat performance by a cell operating out of the Sharm al-Sheikh airport. The threat to aviation is constant and global; it is not the threat that has changed, but the security measures put into place to counter it. The threat of an inside actor, given just how far support for groups like al-Qaeda and the Islamic State extends, is enormous, even with security measures designed specifically to counter such treachery. 

Another possible cause is a bomb that was able to evade current detention protocols. Aviation counterterrorism strategies have always been forced to evolve in tandem with the threat. Groups like al-Qaeda in the Arabian Peninsula (AQAP) and the Islamic State have talented bomb-makers who have surely taken advantage of the terrorist sanctuaries and bomb laboratories across the region. Taking into account the proliferation of violent extremism and the numbers of foreign fighters and supporters, and the threat to aviation is the highest it has ever been.


For tailored research and analysis, please contact:


Subscribe to IB