Originally Posted by
cappt
Very detailed report.
Conclusion starts on pg192.
And a very difficult report to read as are many of the Russian reports. All kinds of unnecessary detail about unimportant subjects.
And.....for a report with very poor English, a large amount of it is spent criticizing the pilots poor English comprehension(and therefore their ability to read about the effects of contaminated wings).
I was very happy to finally finish reading it.
It appears that these pilots were the only ones who did not de-ice that morning. They were told by the ground engineer that it was not needed. Based on the weather conditions that had occurred while they were at this location, a reasonably sharp and safety minded pilot may very well have disagreed with this report from the engineer.
Apparently, there is a culture of bending or breaking rules in Russia. It cannot be ascertained from the report or CVR whether or not these pilots fell into this category. However, for some reason, the de-ice boots were used while on the ground during taxi out not just a short time in case it was desired to check for proper operation but for quite a long period. However, there was no recording of the reasoning for this action.
It appears from the weather reports that wet snow had fallen and temperatures had decreased likely leading to rough contamination on the wing(not just some frost). However, the aircraft did get airborne and reach several hundred feet of altitude.
If one were to decide to knowingly try this, it would seem to be a prudent idea to wait until a reasonably high speed had been reached prior to retracting the flaps. However, the flaps were retracted at white bug which is the minimum allowable speed to do so and the aircraft lost control.
So in the end, perhaps they were just truly unaware of the contamination and had little situational awareness from a weather point of view and were just testing the de-ice boots on the taxi out, or they intentionally took off with contamination(perhaps assuming it was less significant than what it really was) and lost control.
A couple of things to think about. If the maintenance guy says the wings don't require de-icing, it may be prudent to confirm for yourself. If you somehow do get airborne with contaminated wings, waiting for a higher speed to retract flaps could very well be beneficial.