Experts suspect metal fatigue, engine failure or blast on board in A321 Egypt plane crash

While the official probe into last weekend’s crash of the Russian A321 passenger jet in the Sinai peninsula proceeds, TASS has polled several experts of authority for their off-the-cuff opinions on what may have caused the disaster. The three most-frequently mentioned likely factors are a bomb planted in the plane’s rear, engine failure or fatigue cracks that caused the fuselage to fall apart. St. Petersburg — destination of the ill-fated flight carrying holidaymakers from the Egyptian tourist resort of Sharm El-Sheikh — is in the third day of mourning for victims of Russia’s worst-ever air disaster — 224 passengers and crew, including 25 children. An official explanation of what happened to the A321 liner is not available yet. The air carrier that operated the jet — Kogalymavia — speculates that the plane may have suffered a mechanical impact. The company ruled out technical problems or mistakes by pilots. Also, it pointed out that neither the mixture of Russian and Egyptian fuel nor the 2001 incident in which the plane’s tail was damaged could hardly affect the plane’s condition or the operation of onboard equipment. The head of Russian air transport authority Rosaviatsiya, Alexander Neradko, has described such statements as premature. The Egyptian panel of inquiry, he said, has not begun to analyze data contained in the cockpit voice and flight data recorders. This procedure will begin only when all participants in the investigation gather in Egypt. Russian specialists have already taken a look at the "black boxes" to say that at first sight their condition is satisfactory, Neradko said. According to a source in Cairo, there are no traces of explosives on the plane’s fragments studied so far. Russian society has reacted to the A321 crash as a national tragedy. Mourners have rallied in many cities across the nation. On Sunday, the day after the crash, all entertainment events were canceled and television channels have revised their broadcasting schedules for several days preceding the victims’ funerals. In St. Petersburg, local taxicab drivers were giving victims’ relatives free rides to Pulkovo airport. People’s natural reaction to the tragedy has been to change their holiday plans and cancel trips abroad. The A321 crash brought a slump in sales of all foreign tours of 30% to 50%. The Russian Tourist Industry Union has said the market is "stunned." Holiday-makers are handing in already pre-paid vouchers. Number One question both specialists and passengers are asking is what the plane crash was due to. On Monday, it was officially confirmed that the liner fell apart in the air. Many aviation industry experts agree that the impact that tore off the plane’s tail was instant and very brief. Test pilot Magomed Tolboyev, of the Gromov Flight Research Institute, told the daily Moskovsky Komsomolets: "It is pretty clear even to the layman that the plane has many technical hatches where a bomb may be planted." Russian veteran pilot and former flight director of Vnukovo airlines Yury Sytnik also does not rule out this possibility. Military pilot Valery Burkov, holder of the Hero of the Soviet Union title and president of the Heroes of the Fatherland foundation, suspects a terrorist attack. "When a plane’s tail falls off, it is a sure sign there was an explosion on board." A leading aviation specialist who has preferred to stay anonymous has shared with TASS his own analysis of the plane’s crash. "When a plane loses the tail part but no external impact has been identified there are enough reasons to suspect metal fatigue. Some experts argue the A321 crashed because back in 2001 its tail touched the runway during a landing. That does not matter at all. Tail strikes during takeoffs and landings are commonplace. What really matters is the quality of repairs that follow," the source said. "A crack in the plane’s rear that remained unnoticed during repairs may have affected the plane’s controllability. The crack gaped open, the tail fell off, and the plane plummeted. When decompression is instant, the pilot cannot do anything. After full decompression the human body stays alive for just seventeen seconds. That’s the time the captain has to put on the oxygen mask, to see to it that all passengers and crew do so too, and to contact air traffic controllers on the ground. Apparently the pilot did not have even these 17 seconds. He lost consciousness that very moment. Breathing without an oxygen mask is possible only at altitudes below 4,000 meters," the expert explained. According to the analyst the plane performed some strange up and down manoeuvres after takeoff: "Engine failure is not to blame. That the pilot tried to gain altitude indicates that at least one engine was working." The source does not rule out a terrorist attack. Somebody may have planted a bomb on board — many such incidents have occurred in the past. Retired air force Major General Alexander Tsalko advances a similar version. "I believe a terrorist attack was possible. It is enough to put just 50 grams of explosive in some technical hatch in the plane’s rear to cause the whole aircraft to fall apart. This is one likely cause. Engine failure is another possibility. The moment one of the two engines goes dead the other, still operational, pushes its side of the plane forward. Its thrust is distributed asymmetrically. The plane begins to turn and the strain on the plane’s frame soars with the net effect of the tail falling off," Tsalko said. "Or one can imagine another situation. First the engine fails to start. After the second attempt to start it the engine explodes, the turbine is destroyed and hits the fuselage to hack off a large piece. One should not forget that the A321’s tail was damaged during a landing in 2001. That incident is in the flight history. The plane’s tail is always subjected to variable strains. Its task is to keep the plane in its proper position. Air pockets or high turbulence may have subjected the plane’s tail to multiple shocks, thus causing fatigue cracks and eventual destruction."