Grams luftfartsblogg: Malaysian MH370 - 5 år siden i dag

MH 370 - 5 Years

Tomorrow is the 5th anniversary of the disappearance of Malaysia Flight 370, a Boeing 777 which flew off course and appears to have run out of fuel in the South Indian Ocean. Only pieces of the airplane have been found and there has been no determination of what happened. Two hundred and thirty-nine people died in the accident. In her book, The Crash Detectives Investigating the World's Most Mysterious Air Disasters, published by Penguin in 2016, Christine Negroni presents a scenario of what might have initiated the series of events that ended in disaster. This is an excerpt from her book.

No one knows for sure what happened aboard Malaysia Airlines Flight 370, which disappeared five years ago tomorrow. The scenario I am about to describe is based on a framework of events put forward by Malaysian and Australian investigators and other sources who participated in gathering or analyzing the known data.

To this I have applied Occam's razor, the principle that suggests that if there are many possible explanations for something, the simplest is the most likely.

Shortly after midnight on March 8, 2014, and seemingly without warning, what had been an entirely normal flight devolved into an illogical series of events including a seemingly deliberate variation in the route of flight that concluded with the airplane flying off course and until it ran out of fuel somewhere over South Indian Ocean. Such an unraveling has been seen before: when pilots are afflicted with altitude sickness, known as hypoxia.

An inability to get enough oxygen into the lungs to maintain executive function happens when airplanes lose pressurization, and that can happen for a variety of reasons. It can be triggered by an electrical problem or some mechanical difficulty. Pilots sometimes fail to turn the pressurization on at the beginning of the flight, but even when the pressurization is working as it should, there's no way to keep a plane pressurized if there is a hole in the fuselage or if leaks at the seals that allows the denser air to escape.

At the time of the MH-370 disaster, people were boarding airplanes around the world at a rate of eight million a day. Few air travelers then (or now) gave a thought to the fact that outside those aluminum walls the air is too thin to sustain cogent thought.

Still, at least 40 to 50 times a year, an airliner somewhere in the world will encounter a rapid decompression, according to a study for the Aviation Medical Society of Australia and New Zealand.

The reason we don't see tragedies more often is that pilots are taught what to do. First, they put on their emergency oxygen masks. Then they verify that the system is on. There are many cases of pilots discovering that they failed to set cabin altitude upon takeoff. If pressurization was set correctly and is still not working, pilots immediately begin a rapid descent to an altitude where supplemental oxygen is not necessary. When pilots do not follow these steps, the situation spins out of control quickly.

On an American Trans Air flight in 1996, a mind-boggling sequence of events brought a Boeing 727 a hairbreadth from catastrophe. ATA flight 406 departed Chicago's Midway Airport bound for St. Petersburg, Florida. At 33,000 feet, a warning horn sounded because the altitude in the cabin was registering 14,000 feet. First Officer Kerry Green was flying. He immediately put on his emergency oxygen mask. Captain Millard Doyle did not, opting to try to diagnose the problem. He instructed the flight engineer, Timothy Feiring, who was sitting behind and to his right, to silence the alarm.

Doubtless already feeling the effects of steadily increasing altitude, Feiring could not find the control. The captain turned his attention to the flight attendant in the cockpit, asking her if the passenger oxygen masks had dropped. They had, she replied, and promptly collapsed in the doorway. Captain Doyle reached for his own mask, but it was too late. Disoriented and uncoordinated, he could not place it over his head, and he passed out too.

Two of four people in the cockpit were now incapacitated and Feiring was having trouble thinking. He mistakenly opened an outflow valve, creating a rapid and total decompression of the airplane. He put on his mask and then got up to attend to the unconscious flight attendant, placing the flight observer mask on her face but dislodging his own in the process. He passed out, falling over the center console between the two pilots' seats.

Through all this, First Officer Green, with his mask on, was taking the plane down to a lower altitude at a speed of about 4,000 to 5,000 feet per minute. His action allowed American Trans Air Flight 406 to land safely in Indianapolis.

The story, equal parts chilling and absurd, tells me that knowing what to do does not mean pilots will actually do it if their ability to think has begun to deteriorate.

Nine years after Flight 406, a Boeing 737 took off from Cyprus on August 14, 2005, on a flight to Athens. Helios Flight 522 ran out of fuel and crashed into a mountain south of the airport after flying on autopilot for more than two hours-long after the pilots and nearly everyone else on board had fallen into deep and prolonged unconsciousness. They had been starved of oxygen, presumably because the pilots failed to pressurize the aircraft after takeoff. The pilots were hypoxic before they realized what had gone wrong.

The Helios 522 disaster started about five and a half minutes after takeoff, as the plane climbed through 12,000 feet. A warning horn alerted the pilots that the altitude in the cabin had exceeded 10,000 feet. Less than two minutes later, the passenger oxygen masks dropped, but Captain Hans-Jürgen Merten and First Officer Pampos Charalambous did not put on their masks, deciding instead to try to figure out what was wrong: a classic case of impaired judgment due to hypoxia.

For nearly eight minutes, Captain Merten conversed by radio with the operations center in Cyprus in an exchange that grew increasingly confusing to the crew on the ground. As Helios 522 continued its ascent, Captain Merten collapsed at his last position, checking a switch panel behind his seat. First Officer Charalambous passed out against the airplane control yoke.

We can assume that the passengers and flight attendants were uneasy once their masks dropped; everyone waited for news from the flight deck that did not come. The cabin crew had emergency oxygen bottles and portable oxygen masks. With more than a half-hour's supply in each, they were likely conscious longer than the passengers.

Twenty-five-year-old Andreas Prodromou was a flight attendant who also happened to be a private pilot. Around two hours into the emergency he entered the flight deck. He saw the first officer lifeless in the right-hand seat and the captain behind the left seat.

Prodromou put on the captain's oxygen mask as the last of the left engine's fuel was spraying into the combustion chamber. For two and a half minutes he scanned the instrument panel while the airplane picked up speed in descent. He called for help in a frail and frightened voice. "Mayday, mayday, Helios Flight 522 Athens..." The radio was not set to the proper frequency to transmit the message so Prodromou's mayday would only be heard in the post-crash examination of the cockpit voice recorder.

In the early days of the Malaysia 370 mystery, I thought of these previous events. After all, MH 370 was an ordinary flight-under the command of an experienced and well-regarded captain-that suddenly turned baffling.

The Boeing 777 had departed Kuala Lumpur International Airport on March 8, 2014, on an overnight trip to Beijing. Captain Zaharie Ahmad Shah, a 33-year employee of the company, was in command. He had 18,000 flight hours. Professionally speaking, First Officer Fariq Abdul Hamid was everything Zaharie was not. Inexperienced on the Boeing 777, he was still training on the wide-body while Zaharie supervised his performance. The flight to Beijing would bring the young pilot's total hours on the airplane to 39.

The moonless night was warm and dark with mostly cloudy skies when the jetliner lifted off at 12:41 a.m. on Saturday morning. Fariq was making the radio calls, so we can assume Zaharie was flying the airplane. Twenty minutes after takeoff, at 1:01 a.m., the plane reached its assigned altitude, 35,000 feet, and Fariq notified controllers.

Independent of what the pilots were doing, the 12-year-old Boeing 777 was relaying through satellites a routine status message with information about its current state of health. In the acronym-loving world of aviation, this data uplink is called ACARS, for Aircraft Communications Addressing and Reporting System. The automatic status report is transmitted on a schedule set by the airline. At Malaysia, it was every 30 minutes.

Around the time the ACARS message was being sent, it appears control of the flight was transferred to the first officer because Captain Zaharie was now making the radio calls. He confirmed to air traffic control that the plane was flying at cruise altitude. Eleven minutes later, as the airplane neared the end of Malaysian airspace, the controller gave the crew the frequency to which they should tune their radio upon crossing into Vietnam's airspace.

"Malaysian Three Seven Zero, contact Ho Chi Minh one two zero decimal niner, good night." "Good night Malaysian," Zaharie replied. It was 1:19. His voice was calm, according to a stress analyst who listened to the recording as part of the Malaysian probe. There was no indication of trouble.

Zaharie, 53, had been in his seat since around 11:00 p.m., ordering fuel, entering information in the onboard computers, arming systems, checking the weather en route, and discussing the flight with the cabin attendants. He had also been supervising Fariq, who, after landing in Beijing, would be checked out on the Boeing 777.

The airliner was at cruise altitude, flying a pre-programmed course. There was very little difference at this point between the Boeing 777 and every other jetliner Fariq had flown. So, in the scenario I envision on Malaysia 370, this would have been the perfect time for Zaharie to tell Fariq, "Your airplane," leaving the triple-seven in the first officer's hands so he could go to the bathroom.

While Zaharie was out of the cockpit, it would be Fariq's job to tune the radio to the air traffic control at Ho Chi Minh City. But instead of making that switch, the transponder stopped transmitting entirely. The question is why. Fariq knew he had to get the squawk code from Ho Chi Minh-but first he had to tune the radio to that frequency. This is about the time when, I think, a rapid decompression happened near or in the cockpit.

The first officer would have recognized the emergency immediately. The denser air inside the first officer's body would have rushed out through every orifice. His fingers, hands, and arms would have started to move spastically. Fariq would have struggled to understand this rapid change from normal to pandemonium while irretrievable seconds of intellectual capacity ticked away.

He would have reached over to the transponder to enter 7700, the four digits that will alert everyone on the ground and in the air that something has gone wrong with the plane. His fingers would still have been trembling as he clutched the small round knob on the bottom left of the device and turned it to Standby. It is not what he would have intended, but in an attempt to transmit a message of distress, he would have inadvertently severed the only means air controllers had of identifying his airplane and the details of his flight.

I find it logical to assume that Zaharie was in the business class bathroom near the flight deck. Imagine what it would have been like for him to experience the decompression there, to see the yellow plastic cup bob down. He had to make a choice: Try to get back to the cockpit without supplemental oxygen, or remain in the bathroom and wait for Fariq to get the airplane to a lower altitude and then rejoin him on the flight deck. I'm guessing Zaharie wasn't confident in Fariq's ability.

Pilots at Malaysia Airlines tell me that in a rapid decompression, it would have been very difficult for Captain Zaharie to get back onto the flight deck in time. The captain was unable to regain command of the airplane. If he had, things might have turned out differently.

By: Christine Negroni

author of The Crash Detectives Investigating the World's

Most Mysterious Air Disasters

Published by Penguin Books