niedziela, 15 lutego 2015

The weirdest plane crashes- Digits, numbers and sides Part 2

Aviation relies on numbers. Distances, altitudes, frequencies, heights and different calibrations. Many crashes are caused by crews, that make mistakes in the aspect of the multiple numbers, sometimes leading to crashes.In aviation you also get to deal with sides, but it's quite difficult to make mistakes in this area. Or isn't it?
Another problem is lateralization a purely psychological term. It isn't much more than an asymmetry of functionality of neither the left or right side of your body, caused by the work of your brain hemispheres ( cerebral hemispheres as Wikipedia suggests, I won't listen to it though). Important for a pilot, specially in critical situations, such as engine failure. Some pilots can't eventually judge it, flying with all engines dead, but still believing they shut down the correct engine. Eventually this has happened a lot of times. British midland 92 is a sad example of this.
Digits, they aren't as deadly, but they are a potential hazard to pilots. They can be qualified as a problem with numbers, in a way they are. Today is time for another post about air crashes, this time maybe not the weirdest ones, but caused by a tiny error. they could have been prevented, but this time there is going to be more crashes with survivors.
Same introduction, well I know. Now it is time for some different crashes. At first let's bring up the story of an Il-18 that crashed in Slovakia, due to a very basic and unprofessional mistake.
CSA 001 A Multiple Error
In 1976, the Ilyushin 18 was a successful turboprop airliner. It was still in production and in use with many countries of the Warsaw Pact. One of them was Czechoslovakia. The national airline CSA operated Il-18 as well. One of these aircraft was OK-NAB. On 28th July 1976 it was taking a routine flight from Prague to Bratislava. The plane took off after 8:52pm carrying 76 people on board. Around 9:29pm the crew  started descending. Six minutes later the ATC cleared CSA 001 to land at runway 22. At the time the Il-18 was well above the desired altitude. The captain decided to descent at a much too fast rate and this caused the plane to increase speed, noting that the plane is very close to the airport.  The pilots pulled the throttles to idle ground and deployed full flaps, hoping that the ilyushin will slow down. Eventually engine no.3 couldn't sustain the heavy braking and low power setting shutting itself down. The pilot shut down eng no.3 and no.4 at an altitude of 40 metres. The airplane had no power on the right wing and the ilyushin began banking right excessively. It flew over the airport area and fell into a dive. Shortly it hit a leisure resort Zlete Pisky.

Out of 76 people on board, only three survived. The Czechoslovakian investigators concluded that the contributing factors were:
improper handling levers inboard engines

  • reduce speed in the final stage of the final approach below the permissible limit
  •  Feathering 4. Engine
  • not inclined  plane on the side of the working engine
  • cause of the plane crash was an attempt to start the engine at low speed at low altitude
  • In general the pilot that shutdown the engine was mislead by a problem with the engine that occurred earlier. The engine 4 alarm would go on, while there was no problem. The flight engineer and the co-pilot were instructed to monitor it. In the critical situation the co-pilot thought that the engine was actually in trouble.
    Not really a crash caused  by choosing sides or numbers, but had a similar concept. I personally think that the co-pilot may have been thinking that he is shutting down a dead engine, as he didn't realize about the faulty warning. He was probably under high stress and didn't visually check the engine. He did that in the last phase of the flight, however his efforts were in vain, as he didn't have sufficient time.
    Sadly another crash caused by a very basic error, in this case not relying on your own senses, a problem with sides and bad decisions.
    Courtsey of
    A farely similar accident occurred in 1979, Los Angeles while a Nord 262 crashed shortly afte takoef killing three out of seven on board. The autofeather system featherd the right engine, with the crew confused and eventually shutting down the left engine. The automatic system failed due to a broken wire providing the system wrong information.  Automats might be helpful, but at times they can trigure a chain of deadly events. As in this case it resulted in the death of three people.
    In memory of all lost in these crashes.