delphiandomine
9 Sep 2010
News / Crash of Tu-154 at Smolensk-North--could it have been a bomb in the Polish plane? [233]
We don't know this - because we don't know what equipment was installed at Smolensk-North. There are some educated guesses based on what's actually visible, but no-one has confirmed anything for certain.
Also - timewise - think of it like this. They were cleared to 100m, but in reality, were only cleared to 120m or so (due to the rules surrounding the operation of the Tupolev). The ATC guy doesn't know or care about the Tupolev rules - all he knows or cares about is that the plane shouldn't go below 100m without permission. So - the plane goes below 100m. By the time the radar updates, the plane will already be below 100m - and by the time the ATC guy realises what's going on, he issues the Horizon command - which is consistent with the plane already being too low to recover due to the well-documented inability of the Tupolev to pull up without losing height.
One thing to bear in mind is that they were guided to 100m and no more.
Smolensk-North officially is/was all but decommissioned. It's highly unlikely (not least due to the lack of ground equipment) that there was much in the "tower" - why would the Russians bother to keep it equipped when it was decommissioned? Still - we have to wait to see what the Poles say about the equipment installed there.
That's why they should have been using the barometric altimeter and not the radar altimeter. But either way - no matter what altimeter they were using, it still doesn't explain why they went below 100m. Even 100m above the canyon base would have been enough to survive - the real, crucial question is "why did the Captain appear not to react to hearing 90m called out?".
THEY saw the true position of the plane in relation to the ground, not the pilots who were gauging it from the canyons.
We don't know this - because we don't know what equipment was installed at Smolensk-North. There are some educated guesses based on what's actually visible, but no-one has confirmed anything for certain.
Also - timewise - think of it like this. They were cleared to 100m, but in reality, were only cleared to 120m or so (due to the rules surrounding the operation of the Tupolev). The ATC guy doesn't know or care about the Tupolev rules - all he knows or cares about is that the plane shouldn't go below 100m without permission. So - the plane goes below 100m. By the time the radar updates, the plane will already be below 100m - and by the time the ATC guy realises what's going on, he issues the Horizon command - which is consistent with the plane already being too low to recover due to the well-documented inability of the Tupolev to pull up without losing height.
In fog and in the absence of proper equipment, they had to be guided in.
One thing to bear in mind is that they were guided to 100m and no more.
Also, please explain to me this shortcoming as military airports must be better equipped than civil airports like Okięcie. A simple radar reading was needed and for the Russian ATC to stay on the ball and alert.
Smolensk-North officially is/was all but decommissioned. It's highly unlikely (not least due to the lack of ground equipment) that there was much in the "tower" - why would the Russians bother to keep it equipped when it was decommissioned? Still - we have to wait to see what the Poles say about the equipment installed there.
I keep telling you, they didn't stick to the rules as they were being read incorrect info. A 50-metre difference between the canyon base they were going over and the ground level is material, wouldn't you say?
That's why they should have been using the barometric altimeter and not the radar altimeter. But either way - no matter what altimeter they were using, it still doesn't explain why they went below 100m. Even 100m above the canyon base would have been enough to survive - the real, crucial question is "why did the Captain appear not to react to hearing 90m called out?".