Black Box Evaluation: 3500 Data Per Second

The black boxes of the Boeing 737 Max 8 could explain why the machine crashed. The amount of data is enormous, the analysis could take months.

Little time? At the end of the text there is a summary.

The Boeing 737 Max 8 was almost full when it lifted off the 07R runway at Addis Ababa Bole International Airport shortly after half past eight in the morning.

Actually she was supposed to fly to Nairobi, but shortly after the start the pilots reported technical problems and asked to be allowed to turn back. The control center gave the permission, but then broke the connection to the pilot abruptly. The plane had crashed after a good six minutes flying time. All 157 people on board were killed.

The cause of the crash on 10 March is still completely unclear. Answers should now bring the black box. The voice recorder records everything that is said in the cockpit, the conversations of the pilots and the radio messages. The data recorder records the flight history and captures information such as altitude, speed and settings of the aircraft.

At first it was said that the Cockpit Voice Recorder (CVR) and the Flight Data Recorder (FDR) should be investigated in Germany. However, the German Federal Bureau of Aircraft Accident Investigation (BFU) has rejected an evaluation of the black boxes. "We do not have the necessary technology to evaluate the new black boxes, which also have a new software," said BFU spokesman Germout Friday to SPIEGEL.

In the video: Pilots need enough training



Instead, the flight recorders are now being studied in France. How long the analysis will take is unclear. "The reading of the data takes different lengths, sometimes this is very fast - within minutes," says Friday. "The data carriers can be thought of as something like an SD card." It is crucial in which condition the flight recorders are and how well they have survived the crash.

Generally, a black box is designed to withstand a crash and protect the storage inside. "We were able to evaluate flight recorders from completely burnt aircraft," says Freitag. The black boxes could survive temperatures of 1100 degrees Celsius over one hour when burning kerosene.

Getty ImagesTwo horror crashes within just five monthsBoeing's faulty design

"The analysis and analysis of the data can last months," says Freitag. The Flight Data Recorder records about 3500 flight information per second. The decision about where the flight recorders are examined and which data is evaluated usually hits the country where the plane crashed. In the current crash, the decision therefore lies with Ethiopia.

Often the black boxes are examined in the competent authorities of the producing countries of the aircraft, which have black box laboratories. In this case, that would be the USA. Why Ethiopia has decided against it is unclear.

The French aviation accident investigation authority (BEA) has since confirmed that Ethiopian authorities have requested assistance. An Ethiopian delegation brought the black boxes to Paris. BEA itself will give no information about the progress of the investigation, it would be the exclusive responsibility of the Ethiopian authorities, the authority said on Twitter.

⚠️ 03/10 accident to the # Boeing737Max @BoeingAirplanes ET-AVJ operated by @flyethiopian / Ethiopian authorities have requested @BEA_Aero assistance for the analysis of FDR & CVR / Any communication on the investigation progress is the responsibility of those Authorities.

- BEA | Bureau d'Enquêtes & d'Analyzes ✈️ (@BEA_Aero) 13 March 2019

The crashed Boeing 737 Max 8 had been delivered to Ethiopian Airlines in November and had completed 1,200 field operations in the air. There were no abnormalities at the last big check on the 4th of February and no incidents are known from previous flights.

According to US and Canadian investigators, there are indications that the Boeing 737 Max 8 may have crashed for a similar reason to the Lion Air aircraft before, reports the New York Times. According to satellite data showed that the machine did not gain in height evenly, but was repeatedly bagged.

Also, data from the online platform Flightradar 24, which records the flight position of aircraft worldwide, show irregularities in the vertical airspeed. An indication that the machine has repeatedly gone into a descent.


Flight altitude (blue), speed (red), vertical speed (green) of Ethiopian Airlines engine

A similar pattern was also seen in the previously crashed Lion Air machine. The reason could have been a mistake in the software MCAS (Maneuvering Characteristics Augmentation System), according to the current state of investigation. It should ensure that the nose of the aircraft lowers in a stall.

On the Lion Air machine, a faulty sensor or software error apparently caused the nose of the aircraft to sink again and again, although this would not have been necessary at all. The pilots have apparently tried several times to pull his nose back up before the machine crashed into the sea.


Flight altitude (blue), speed (red), vertical speed (green) of the Lion Air machine one minute before the crash

Similar software problems had already been reported by US pilots in November 2018. They reported that the head of the Boeing 737 Max had dropped surprisingly shortly after the start - just a few seconds after the pilots had turned on the autopilot.

Only when they switched off the automatic again, the machine had continued to rise as planned. In such a case, they were not sufficiently prepared, the pilots criticized. The software is just as new as the Boeing 737 Max. The briefing included only three hours of training on the computer and a familiarization flight when the aircraft was introduced.


Flight recorder (archive photo)

Whether the speed variations in the Ethiopian Airlines machine were actually caused by a software error, however, is still completely unclear. Experts consider a conclusion on the cause of the crash solely on the basis of satellite data for not meaningful. The investigations have just begun and even the cause of the crash of the Lion Air machine has not yet been finally clarified. Although there is an interim report, the final analysis will not be published until September.

In summary: The black boxes of the crashed in Ethiopia Boeing 737 Max 8 could clarify how it came to the crash. They are to be evaluated in France. An analysis may take months. Meanwhile, there is new speculation that the machine had crashed for a similar reason as the identical Lion-Air machine end of October. Thus, a software error or a damaged sensor could have caused the on-board computer to steer the aircraft toward the ground. However, experts warn against premature conclusions on the cause of the crash. Reliable answers can only provide an analysis of the black box.

ref: spiegel