If the machine is overloaded, the pilots again and again

anyone Who has in the Cockpit actually Say it: man or machine?, many of the passengers questions for this week. After in October, a Boeing 737 Max 8 of the Indonesian Lion Air was shortly after the Start, crashed into the sea, crashed a few days ago an identical machine also shortly after Lift-off in Ethiopia. Yet, we know little about the second cause of the disaster, the crash in October, however, a new Software played a crucial role. Because it is possible that the second crash with similar causes, must remain the Boeing 737 Max, currently in many countries on the ground.

discussion of automated AIDS in the Cockpit are there for a long time. The Computer, on planes, even more than in the cars of numerous other tasks. "Almost every part of the system has its own Computer," says Christoph Regli. He directs the Department of aviation at the Zurich University of Applied Sciences (ZHAW) and the self line is a pilot and a computer engineer, ETH. There are assistance systems which assist the pilot in his work, and there is the autopilot that takes over the control completely. Take-offs and landings, flying the pilots in the majority of cases, but even with the support of the digital assistant. The Autopilot takes over a certain altitude.

experience decides

The pilots have also almost always the possibility of the automated systems shut down. In an emergency, however, there are two challenges. A critical Situation close to the ground, during takeoff or landing, every second counts. "No Pilot then the time, long check sure lists," says Regli. These checklists provide the steps in case of an emergency, you would have to shut down the systems. In addition, the Pilot has to remember which systems belong to for problems, and shut down what may be under time pressure is difficult.

pressure is not only time demanding. Although the pilots of each of the emergency scenario to practice regularly in the Simulator, but a real emergency can feel quite different. To control a large Linienjet without automated assistance systems is, even if x-practiced specialist, not a common maneuver for a pilot.

"it is A very important factor here is the experience," says Regli. A good example is the successful ditching of Chesley B. Sully, called Sully, in the year 2009 on the Hudson River in New York. Sully had over hours 20'000 flight, as he was after the failure of two engines, the maneuvers.

Various media outlets reported after the crash on Sunday, the captain of the Ethiopian flight was 29 years young, but had already completed 8000 hours of flight time. His Co-Pilot brought it to 200 hours. In the US, a Co must be able to produce Pilot 1500 hours of flight time before he is allowed to Linienjets taxes at all. In Switzerland, there are 200 hours. Crucial in an emergency situation is that the captain and Co-Pilot work together as a Team.

The Autopilot was originally intended to relieve the pilot of routine tasks to help you see, for example, to keep the correct altitude and speed are constant. "It is an almost philosophical question, whether the machine supports the people or patronized," says Regli.

In the eighties, the French aircraft manufacturer Airbus introduced the so-called Flight Envelope Protection System. It should move to keep the pilots before the abrupt, dangerous flight maneuvers, so certain parameters within which the aircraft. A Pilot wants to fly, for example, a risky maneuver, a stall could threaten to turn on the Computer is correct.

if you Worry because of the own Computer around bitch, you should know that the aircraft software has to go through a much more rigorous examination for possible errors, as the commercial solutions on the local PC. However, the automated systems are dependent on data from all possible Sensors to be able to respond to situations.

Sensor Defective

These Sensors are usually in several versions, according to the principle of redundancy, which plays in the safety of the flight, a key role. If one System fails, there is a Backup. Each Software can only work correctly if the Sensors provide correct data. "The dependence of correctly working Sensors is a fundamental Problem of automation," says Professor Michel Guillaume, head of the centre for aviation at the ZHAW and in addition, at the ETH Zurich teaches. One of the witnesses in the unmanned driving or flying is even more acute.

A defective Sensor also played in the crash of the Indonesian Lion Air a role. The Sensor that measures the angle of attack, i.e. the angle between the wing and the air current sent the wrong data in the on-Board computer. Therefore, one of Boeing's newly developed Software turned on, to prevent Flow separation. This new Software introduced by Boeing with the 737 Max, is the focus of the investigators to the crash in October. The Maneuvering Characteristics Augmentation System (MCAS) have been developed by the aircraft manufacturer, because of the new type of aircraft larger engine has the works, sitting further forward on the wing. This has shifted the focus of the machine, and the risk of flow increases the demolition of.

the principle of redundancy plays in an important role.

may be A stall, if the nose of the aircraft goes too far to the top. The aircraft then falls like a stone from the sky. Dangerous such especially close to the ground. It happens in a great height, to intercept the pilot of the machine again. To do this, you have to work against the Intuition, which is under the pressure of time is only possible if you have practiced it countless times. If the aircraft is in free fall, you must press the pilots of the nose to the bottom so that the air flows around the wing and the aerodynamics of the aircraft can again fly.

"the Pilot made a mistake,"

the Pilot of The Lion Air realized that he fought to suppress the MCAS. He moved the nose about twenty times to the top, and the Software that guessed incorrectly a stall, shoved her back down. "The Pilot has made a mistake," said US aviation expert Peter Lemme, who has previously worked at Boeing as an engineer. However, there was also criticism of Boeing, because the company is not, or too little, had drawn the attention of the pilots on the MCAS. Now Boeing needs to revise the System on the instructions of the American regulatory authorities to in April.

Still, we know too little about the crash from Sunday. However, there are certain Parallels between the two disasters. Also, the Pilot of the Ethiopian plane struggled to leave the machine to rise. In an Interview with CNN, the CEO of the Airline said the Pilot had reported to the Tower are also problems with the flight controls, as he asked prior to the crash, to be able to return. The "New York Times" reported two further cases in the United States, in which pilots reported in the late autumn of the problems with the MCAS, because it pushed the nose down. You were able to solve these problems but, by turning off the respective systems. Meanwhile, actually, all of the line should know of the pilots on the MCAS decision.

How risky it is at the moment, as a passenger in a 737 Max to fly, the experts are not in agreement. Christoph Regli would not continue to fly, Michel Guillaume, before there are clearer answers. He pointed out, however, that the plane is the safest transport is statistically still. "Almost every second of starts in the world on a plane, in comparison, few accidents happen."

(editing Tamedia)

Created: 14.03.2019, 09:09 PM