(CNN)It appears that EgyptAir 804, which crashed into the Mediterranean Sea on May 19, killing all 66 people on board, may have suffered a significant smoke and fire event.

Although the transcript of the cockpit voice recorder, or CVR, has not been publicly revealed, EgyptAir sources have released information that indicates, from cockpit conversation, that one of the pilots may have been attempting to extinguish a fire or eliminate smoke.
    In addition, according to earlier details from the Egyptian Accident Investigation Committee, recovered wreckage from the forward section of the A-320 shows evidence of “thick, black smoke” and heat damage.



      Data recovered from EgyptAir Flight 804 black box


    Finally, the last two messages transmitted a fault in the autopilot system and then a fault in a portion of the flight controls.
    What does all the new evidence imply? Again, we don’t know all the facts yet, but it is possible that a mechanical malfunction within the A-320’s systems may have begun as an overheat situation and erupted into a fire inside the confines of the electronics bay.
    The electronics bay is the brains of the airplane. The bay contains the flight management computers that direct almost every aspect of airplane operation: communications, flight control movement, environmental systems, and more.
    Unlike the two cargo compartments, no fire suppressant system is designed into the electronics bay of the Airbus because fire retardant material releases particles that infiltrate the functionality of sensitive electronics and could cause havoc. Instead, a venting system is utilized that theoretically evacuates smoke.
    On a fly-by-wire airplane, controlled by a computer system, a fire could potentially disable the crew’s ability to adequately control the airplane. The pilot’s oxygen system, utilized in the event of a depressurization event, is also in the electronics bay. If fire or extreme heat compromised the hoses connected to the cockpit, pure oxygen has the potential to ignite rapidly and/or explode.
    Based on the facts conveyed so far, we can speculate that the faults transmitted by ACARS occurred as a result of electronic circuitry nearest the source of the overheat/fire being affected first. And then at some point, everything in the electronics bay could have succumbed to the event. Forward lavatory smoke would certainly be indicative of a fire or overheat condition coming from below the floor where the electronics bay is located.
    It is also plausible that the first fault indication, the copilot’s side window having an anti-ice heating issue, may have resulted in a catastrophic failure that involved a cracked interior pane caused by a fire in the heating element sandwiched in-between the glass. A pilot’s immediate reaction, other than to flinch, is to shut off the power to the offending window. And then, if a fire were evident, someone would have used the portable, cockpit Halon fire-extinguishing bottle.
    Although cockpit window cracking can be an alarming and spectacular event, seldom is the situation serious enough to completely compromise the integrity of the offending window: There are two thick panes of glass. Something else would have to have occurred for the pilots to lose complete control of the airplane.
    Is a terrorism-planted explosive device still a possibility? Sure. But this new information makes it less likely. Regardless, where there is smoke, there is high probability that there is fire.

    Read more: http://www.cnn.com/2016/07/05/opinions/egyptair-crash-black-box-info-abend/index.html

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