Discussing this event with some friends of mine, one was even mentioning the possibility of a hidden glitch inside the very complex Su-35 FBW,:love-struck: not a pilot error. Told him similar written here, shortened approach, higher landing speed, extreme movements with rudder and stabs above the rwy bcs of a sideslip, pilot fckd it up, but still there was something bugging us meaning the violent roll movement to the left when aircraft bouncing off the rwy. Due to your stubborness and pointing to the TVC, I looked those few pictures available again and voila.
We completely forgot that the SDU-427 allows TVC assisted take-offs and landings as well, but assuming it is not usually recommended. Pilot forgot to turn it off or deliberately used it, but overestimated his flying skills.
Pictures below are from the website https://www.flickr.com/photos/27rus/sets/72157646109709609/ also the video http://www.odnoklassniki.ru/video/5651367178 confirms as well, pilot landed with TVC on, what could make a terrifying experience when landing with a sideslip using too much rudder input, then the TVC nozzle is turning to the direction of the rudder creating violet roll momentum when bouncing off the runway.
Pilot flying the blue camouflaged SU-35 on the airshow was landing with TVC off, note the nozzle alignment.[ATTACH=CONFIG]231274[/ATTACH][ATTACH=CONFIG]231275[/ATTACH][ATTACH=CONFIG]231276[/ATTACH][ATTACH=CONFIG]231277[/ATTACH]
yes. I had at first the same idea. I suspected like you that the hot gases out-flowing from the nozzle might have destabilized the plane just before touch down. But this is wrong. Just like the TVC mandatory off during landing (see Berkut post that know much more than me abt the bird).
The picture I posted show clearly that there was a “huge” asymmetry during touchdown + a residual slideslip that the TVC are in fact correcting at the very same moment. The first pick that you’ve linked on FlickR even confirms what I depicted with my pic. Even if the photo shoot started just after touchdown. Notice that the left leg is more compressed that its right counterpart.
I then tried to understand why the rebound was so pronounced. It is obvious than before the wing tip touched the ground, the TVC can not be finger pointed. However, the fact that TVC were pointed upward just before landing, indicates that the TVC sensed that the speed was to low for the alpha required by the pilot and compensated to grant the pilot the possibility to correct the sink rate.
Hence, in fact, the TVC seems to have acted positively even before this slight mishap.
So, what could have been wrong ?
As crudely shown above, the sink rate was slightly too high. The speed was too low. A residual slideslip was present upon touch down and, as the picture I posted earlier show, there was a residual bank angle.
Nothing catastrophic in fact. many time, you can see all those little things during airshow.
Hence… (Jericho trumpets snoring)…
The landing setup (shock absorber or tires pressure) was not adapted to the runway. I don’t know at all if that was the first landing of this Su35 on that runway that day, but, as a rather wild guess, I will say that a more soft ground configuration might have been setup on the landing system.
And I never heard before any mention about such system on the Su ….
😉
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