Aircraft Crash in Moscow
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Is "Cycle Reverse Doors" on the pre push CL? I'm sure it is, since they may soon become necessary, even crucial, for RTO?
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Do "other types" have reverse....."issues"?
See, that is the thing. Pilots are the last to know, officially....these guys in Moscow may not have known what others did.....did they know?
If my beast is fresh out of the shop, I am extremely attentive, let alone if there is paper floating about "bulletin"....
The only thing more hazardous than an a/c that needs maintenance is one that was just maintained.
No offense to Mx....
See, that is the thing. Pilots are the last to know, officially....these guys in Moscow may not have known what others did.....did they know?
If my beast is fresh out of the shop, I am extremely attentive, let alone if there is paper floating about "bulletin"....
The only thing more hazardous than an a/c that needs maintenance is one that was just maintained.
No offense to Mx....
Last edited by Lyman; 1st Jan 2013 at 16:33.
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BOAC,
In Novosibirsk 2P managed to break RCL lock by force. 
From T204 overrun at Novosibirsk thread at aviaforum:
The question remains now what happens if the reversers do not unlock? Are the RCL's locked 'inop'?
From T204 overrun at Novosibirsk thread at aviaforum:
in short: TL at Idle, RCL - small reverse, no wow signal from left strut, so reverse switching is locked, reverse flaps not shifted, engine on direct thrust, PNF pulls hard on RCL to the full revers and having uncommon physical strenght managed to force levers forward thus put engine (praise to the creator only one) on the regime close to the nominal. F/E doesn't notice nor reverse switching nor increase of the thrust when throttles in idle, PF is busy pressing on all possible brakes, incl parking and starting, which leading to the destruction of the wheels, etc.
Lucky they there was was not a fence or a concrete wall in front of them...
Lucky they there was was not a fence or a concrete wall in front of them...
Last edited by Kulverstukas; 2nd Jan 2013 at 11:22.
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I've been watching this thread to and throw for a couple of days now and people seem to be getting blinkered by lack the of rev thrust. I'll appologise for my ramblings in advance but just wanted to get some thoughts out there.
What grabs my attention as an EASA B1 is the underlying cause of this i.e wow sensing issues, which there is type history of or, the fact that the aircraft didn't settle enough onto the oleos due weight/speed/technique or over serviced oleos??
I note from the crash site pictures that the spoiler/speed brake panels were not extended. Perhaps settled back down after hyd px loss but again possibly wow issues but why did the crew not manually extend them on TD? If the Tu thinks it is still GIA will the brake system remain in touchdown protection mode or will wheel spin up allow braking, as on western designs?
Without ground spoilers 'dumping' the majority of the lift how much is braking performance reduced? Do any similar type crews know of any published figures or multiplication factors for landing distance with inop spoilers?
I'm not familiar with the type and therefore don't know how sophisticated the wow sensing systems and resulting t/rev, ground spoilers and antiskid interlocks are but would welcome some specific details on them.
What grabs my attention as an EASA B1 is the underlying cause of this i.e wow sensing issues, which there is type history of or, the fact that the aircraft didn't settle enough onto the oleos due weight/speed/technique or over serviced oleos??
I note from the crash site pictures that the spoiler/speed brake panels were not extended. Perhaps settled back down after hyd px loss but again possibly wow issues but why did the crew not manually extend them on TD? If the Tu thinks it is still GIA will the brake system remain in touchdown protection mode or will wheel spin up allow braking, as on western designs?
Without ground spoilers 'dumping' the majority of the lift how much is braking performance reduced? Do any similar type crews know of any published figures or multiplication factors for landing distance with inop spoilers?
I'm not familiar with the type and therefore don't know how sophisticated the wow sensing systems and resulting t/rev, ground spoilers and antiskid interlocks are but would welcome some specific details on them.
Last edited by orion1210; 1st Jan 2013 at 20:33.
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How many km/h in 100 knots? Plus revision up?
The combination of Mx and judgment/competence is going to be chilling, just a guess. At the very beginning is going to be the approach, landing brief, if any.
Landing lightweight every other hop should satsify the recent experience issue.
The combination of Mx and judgment/competence is going to be chilling, just a guess. At the very beginning is going to be the approach, landing brief, if any.
Landing lightweight every other hop should satsify the recent experience issue.
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So off the end at 140mph? Touch at 165? Or 140 at impact? Is there a link to this autre website?
Здравствуйте все участники данного форума.Всем доброго времени суток.. Кстати-всех вас с наступающим! И всего всего хорошего!
Здравствуйте все участники данного форума.Всем доброго времени суток.. Кстати-всех вас с наступающим! И всего всего хорошего!
Last edited by Lyman; 1st Jan 2013 at 22:55.
Gotta be a chart someplace that shows the effect of the spoilers for certain weights and max anti-skid braking.
Remember that your braking force is better when heavy than when light. So until you hit the brake energy limts, you can mash the pedals and take what you get. I must caution all that the best way to avoid heating and destroying the brakes is to slow down a bit, then mash them. Rule of thumb is half the brake energy for a one-third reduction in speed. This was a big problem in the early days for our little jet, and constantly tapping the brakes at a slow speed heated up the brakes less than "riding " them at a higher taxi speed.
Remember that your braking force is better when heavy than when light. So until you hit the brake energy limts, you can mash the pedals and take what you get. I must caution all that the best way to avoid heating and destroying the brakes is to slow down a bit, then mash them. Rule of thumb is half the brake energy for a one-third reduction in speed. This was a big problem in the early days for our little jet, and constantly tapping the brakes at a slow speed heated up the brakes less than "riding " them at a higher taxi speed.
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Failures of 1 and 3 hydraulic systems will give only 5 degrees of spoilers, but will give main system brakes and in that scenario landing distance is calculated at 2,166 meters with good braking action.
However, the overrun speed given by liider (225 km/h = 121 kts) clearly indicate at least to me, that the only possible failure to explain it is high forward thrust. That doesn't preclude other possible failures, only that no other system malfuction can explain almost total absense of retardation during the entire landing roll. Ofcourse the other possible explanation is an intentional GA attempt, but we don't know enough yet to understand if that had to play a part in the end result.
Btw, the touchdown speed of 262 km/h = 141 kts seems extraordinarily high for an almost empty aircraft of this size and configuration. The Vrefs for a light Tu-204-300 are in the 210 to 230 km/h range, going over 250 only with min flaps and close to MLW.
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Not quite the same but...
... the comparison has been made to the B757 by others. Empty positioning on the B757 would normally see a Vref of about 110Kts, so if speeds are anything like similar, a touchdown at 141Kts would seem a little extreme. And yes - the B757 can be a bit of a hand full when empty - she just loves to fly. The secret seems to be to fly through the normal 20ft flare for half a second or so longer.
We are talking different a/c and wings here though, and I am not familiar with the T204.
We are talking different a/c and wings here though, and I am not familiar with the T204.
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Final Second
I've been doing some photo analysis of the final second of dashcam video of the accident. What impresses me is how rapidly the nose falls into the depression at the end of the runway.
A tricycle gear aircraft is roughly balanced on its main gear with the heavier end on the nose gear. of course, but this means that there should be significantly less than 1 g worth of downward acceleration at the nose of the aircraft unless there is substantial uplift at the tail, heavy braking going on, or perhaps the main gear have hit some substantial obstacle which pitches the aircraft down.
If I was to run off a runway at speed, I think I'd be doing it with full aft stick and trying to keep the pointy end up in the air. The pitch down into the divot at the end of the runway is strange and almost certainly caused the high percentage of fatalities among the crew.
A tricycle gear aircraft is roughly balanced on its main gear with the heavier end on the nose gear. of course, but this means that there should be significantly less than 1 g worth of downward acceleration at the nose of the aircraft unless there is substantial uplift at the tail, heavy braking going on, or perhaps the main gear have hit some substantial obstacle which pitches the aircraft down.
If I was to run off a runway at speed, I think I'd be doing it with full aft stick and trying to keep the pointy end up in the air. The pitch down into the divot at the end of the runway is strange and almost certainly caused the high percentage of fatalities among the crew.
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Mbird:
it would be interesting to see some good photographs of the runway and its relationship to that freeway. It seems it was like they ran into a building, so to speak.
Very, very sad. Unlike some of the airline crashes we have discussed here over time it seems like with this one perhaps the crew was sucked in by various circumstances.
If I was to run off a runway at speed, I think I'd be doing it with full aft stick and trying to keep the pointy end up in the air. The pitch down into the divot at the end of the runway is strange and almost certainly caused the high percentage of fatalities among the crew. 
Very, very sad. Unlike some of the airline crashes we have discussed here over time it seems like with this one perhaps the crew was sucked in by various circumstances.
Where on earth is the figure of 140Kt+ landing speed coming from? I would be surprised if the processing of even the QAR has been completed as yet, let alone the DFDR or CVR, and released to the public, and if there is no series of images that give D/dt for the touchdown point then these figures are rubbish, and rather offensive to the crew who are unable to protect themselves from the inane musings going on here. The 120kt (GS??? IAS/EAS/CAS???) at the DER is also at odds with the video... the aircraft will travel it's own length in 1 second at 45m/sec, which it doesn't appear to, on replay. While this is a rumours network, how about keeping those rumours that are derogatory in respect to competency down to a dull roar until the data is out? Apparently the posters on this site are just as keen as the Russian govt to denigrate the crew. With recent history of the type, I would suggest some caution before defaming the crew further.
Last edited by fdr; 2nd Jan 2013 at 01:38.