Page 1 of 7 123 ... LastLast
Results 1 to 20 of 124

Thread: Aeroflot Superjet 100 fire and evacuation at UUEE

  1. #1
    Junior Member
    Join Date
    Feb 2018
    Posts
    68

    Default Aeroflot Superjet 100 fire and evacuation at UUEE

    Reported fire after takeoff, aircraft was on fire during landing, evacuated after landing.
    Flight SU1492 UUEE-ULMM RA-89098
    12 reported dead, 11 passengers and 1 FA from aft section of aircraft.
    https://youtu.be/D4iG1B44cy0
    https://youtu.be/9yqhyg-t2iU

  2. #2
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    7,037

    Default

    A video shows no smoke and no fire from the aircraft prior to touchdown.
    http://avherald.com/h?article=4c78f3e6&opt=0

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  3. #3
    Senior Member Evan's Avatar
    Join Date
    Jan 2008
    Posts
    6,786

    Default

    There are some people in Moscow feeling extremely lucky to be alive right now. Probably not those who were seated in the back. I expect that death toll will rise.

    Looks like a very hard landing pushed the gear struts through the fuel tanks. Fuse pins aren't much good for extreme vertical loads.

    There's a report that they lost electrical power and FBW reverted to direct (minimum) law. There was also a report of a lightning strike.

    That doesn't fully explain the hard landing though.

  4. #4
    Senior Member Evan's Avatar
    Join Date
    Jan 2008
    Posts
    6,786

    Default

    FYI: there is no mechanical backup on the SSJ. The FBW is extremely robust as a result.

  5. #5
    Junior Member
    Join Date
    Feb 2018
    Posts
    68

    Default

    Likely what happened here is pilots didn't anticipate such quick response from direct law and as a result pulled up too much on the flare, causing a series of bounces

  6. #6
    Senior Member Evan's Avatar
    Join Date
    Jan 2008
    Posts
    6,786

    Default

    Quote Originally Posted by ErmakDimon View Post
    Likely what happened here is pilots didn't anticipate such quick response from direct law and as a result pulled up too much on the flare, causing a series of bounces
    The lit I've read on the SSJ claims that it is quite benign to handle in direct law, partly because it retains all the damping functions. I've even read that some test pilots preferred the handling in direct law.

    On the other hand, unlike the Airbus FBW, the SSJ does not normally switch to direct law in the last part of the final, so pilots probably have never had any real-world experience flying with it.

  7. #7
    Senior Member B757300's Avatar
    Join Date
    May 2003
    Location
    CLL
    Posts
    1,375

    Default

    The death toll has climbed to 41.

    https://www.cbsnews.com/news/deadly-...ay-2019-05-05/

  8. #8
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    7,037

    Default

    Quote Originally Posted by Evan View Post
    Looks like a very hard landing pushed the gear struts through the fuel tanks. Fuse pins aren't much good for extreme vertical loads.
    Well, it shouldn't. Fuse pins are there to prevent that hard landing loads transfer to the wing spar which then acts like a fuse itself. Like in the several DC-10 and MD-11 hard landing accidents where one of the wings pars failed, the airplane lost that wing, and the plane rolled inverted engulfed in flames. A fuse pin is NOT there to prevent the landing gear strut from going through the wing tanks, rather the opposite, sort of. The compression fuse pin is supposed to fail under high landing gear compression stress and let the strut go through the wing, except that there should be no fuel tank there because the landing gear assembly is located behind the rear spar which is the aft end of the fuel tank.

    I suppose that the British Airways 777 accident at Heathrow was a quite harder landing. That accident, being at a high descent rate on soft surface, imposed very high loads both in compression and backwards. One landing gear failed under compression while the other failed under backwards force. One of the fuel tanks (don't remember which one) was protected as per design, the other one was breached because a secondary rod (that gives stability to the assembly) failed to fail as designed, and penetrated the fuel tank. Luckily the soft and wet ground helped avoid a fire.

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  9. #9
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    7,037

    Default

    Couple of quotes from the latest update in AvHerald:

    The Prosecution Office subsequently reported, only 37 occupants have been accounted for and are alive, 41 people are feared dead.

    A ground observer reported he witnessed the landing. The aircraft bounced, on the third critical touchdown both main gear struts collapsed and the aircraft caught fire.
    http://avherald.com/h?article=4c78f3e6&opt=0

    I will say that I would expect that an accident like this would be more survivable. It took only seconds for tha airplane to stop. The fire should not have gone into the cabin so easily. Unless the landing was harder than I think and the fuselage itself broke.

    And as a side comment, you have a plane completely engulfed in flames, people screaming and dying burned, and the people still evacuating with hand luggage. In this accident, this could have caused some additional deaths. I hope someone goes to jail for that and gets highly publicized worldwide.

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  10. #10
    Senior Member Evan's Avatar
    Join Date
    Jan 2008
    Posts
    6,786

    Default

    Quote Originally Posted by Gabriel View Post
    Well, it shouldn't. Fuse pins are there to prevent that hard landing loads transfer to the wing spar which then acts like a fuse itself. Like in the several DC-10 and MD-11 hard landing accidents where one of the wings pars failed, the airplane lost that wing, and the plane rolled inverted engulfed in flames. A fuse pin is NOT there to prevent the landing gear strut from going through the wing tanks, rather the opposite, sort of. The compression fuse pin is supposed to fail under high landing gear compression stress and let the strut go through the wing, except that there should be no fuel tank there because the landing gear assembly is located behind the rear spar which is the aft end of the fuel tank..
    I suppose it's possible that the SSJ gear is also positioned in a way that a vertical load could fracture the wing spars and thus rupture the fuel tanks. It doesn't appear to be the case though, considering the absence of a rollover. Clearly, the gear collapse somehow resulted in ruptured fuel tanks. I also thought of the BA 777 crash, but I assumed the gear struts themselves had caused the fuel tank breach.

  11. #11
    Senior Member TeeVee's Avatar
    Join Date
    Mar 2009
    Location
    MIA
    Posts
    2,045

    Default

    So much for the ultra modern up to date ssj..... hard landing and...

  12. #12
    Junior Member
    Join Date
    Jul 2013
    Location
    London, England
    Posts
    74

    Default

    Did I miss something in the video? An unscheduled landing, particularly without radio contact should have all the emergency bells ringing. Yet where were the fire trucks pursuing the stricken aircraft down the runway? Surely the safest place to land in an emergency is an airport. Whatever happens there should be foam to suppress fire and give the other emergency services time to extract survivors (whom I suppose 100% were alive at touchdown). Haven't we learnt anything since Manchester?

  13. #13
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    7,037

    Default

    Quote Originally Posted by Evan View Post
    I suppose it's possible that the SSJ gear is also positioned in a way that a vertical load could fracture the wing spars and thus rupture the fuel tanks. It doesn't appear to be the case though, considering the absence of a rollover. Clearly, the gear collapse somehow resulted in ruptured fuel tanks.
    For the DC-10 (carried over to the MD-11), something "special" happened. I could not find out exactly how, but the design and certification didn't follow the standard requirements in 14 CFR part 25. Which require the landing gear to fail in a safe mode under compression, longitudinal and lateral force. I don;t know if there was an AMOC (alternate means of compliance) or what, but the DC-10 doesn't have the compression fuse, which is a direct violation of the standard requirements. There are a couple of articles in the FAR 25 that are related to how Douglas certified the DC-10, but thay are "reserved" and hence not accessible to the general public. I was able to read only part of them quoted in one of the NTSB accident reports of one of these accidents.

    Apparently Douglas complained that providing for a safe failure mode in all 3 directions was too complex and instead certified the plane with safe fail in the longitudinal and lateral directions and with an increased resistance in the vertical direction over what is normally required. Which seems to work quite well since what ends up failing is the spar and not the landing gear. This "increased vertical force" concept is what is stated in these reserved FARs.

    The problem is compounded by what I consider to be a substantial flaw in the standard requirements of the conditions how the load must be calculated (which applies both for the reserved and standard requirements). You can't assume more lift than the airplane's weight at the moment of touchdown (but you don't need to assume that it makes any less) and, while you have to consider a bank (and hence the airplane touching down in only one gear), you don't have to consider roll motion. For me those are too ideal conditions. It is perfectly rational to expect that the plane can touch down when it was flying at less than 1G (at least a bit) and rolling. In this particular accident in this report that I mentioned, the plane landed at less than the maximum vertical speed that the landing gear is supposed to withstand, but with less than 1G and rolling towards the side that it was already banked. This made the landing gear achieve maximum compression and once you achieve this point the loads on the gear grow dramatically (because now it's all elasticity of the materials, there is no more oleo-pneumatic anything). This quickly put the force on the gear beyond the increased limit for this special certification, and the spar failed.

    With all this said... Is the SSJ certified by the FAA? I would expect that the FAA doesn't allow this special certification again, not after the bad experience with the DC-10 and MD-11. If it is not certified by the FAA, then I cannot say much because I am not familiar with the European or even less the Russian requirements.

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  14. #14
    Member
    Join Date
    Jun 2005
    Location
    Spokane,Washington,USA [KGEG,KSFF,KSKA]
    Posts
    204

    Default

    Quote Originally Posted by Brainsys View Post
    Did I miss something in the video? An unscheduled landing, particularly without radio contact should have all the emergency bells ringing. Yet where were the fire trucks pursuing the stricken aircraft down the runway? Surely the safest place to land in an emergency is an airport. Whatever happens there should be foam to suppress fire and give the other emergency services time to extract survivors (whom I suppose 100% were alive at touchdown). Haven't we learnt anything since Manchester?
    To be fair this reminds me more of the Cincinnati incident of 1983, as this and that happened while they were already in flight and came in for emergency landings. Whereas Airtours never even got off the ground. Doesn't mean much difference wise though, any situation where there is a plane burning should get the same response regardless if it happened before takeoff or it being a diversion. In this case it coming back to the departure airport. One would think Russia had a handle on such a situation as much as any other "first" world country, but they have had some shady safety records in even recent years, not just former USSR states and equipment, new planes and modern day technology. Last year a plane took a nose dive after taking off from Moscow Domodedovo. Not too long before that the same thing pretty much happened in Rostov, although that was flyDubai I believe so it just happened in Russia, not a Russian plane. *Shrugs* Not saying its the state of safety in the country of Russia, but it isn't a point that should be ignored either.

    Not to mention the debacle that is the Polish president dying in a boneheaded accident on Russian soil in a modern age. So... no matter what happened here there is no denying shit happens in Russia more than many other places it seems. Doesn't take Einstein to see that.
    Last edited by KGEG; 05-06-2019 at 02:42 AM. Reason: Added Thoughts

  15. #15
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    7,037

    Default

    Quote Originally Posted by Brainsys View Post
    Did I miss something in the video? An unscheduled landing, particularly without radio contact should have all the emergency bells ringing. Yet where were the fire trucks pursuing the stricken aircraft down the runway? Surely the safest place to land in an emergency is an airport. Whatever happens there should be foam to suppress fire and give the other emergency services time to extract survivors (whom I suppose 100% were alive at touchdown). Haven't we learnt anything since Manchester?
    Do you have any information about how long it took for the fire trucks to reach the plane? You seem to imply that a lot, but perhaps that was not the case. The plane was fully engulfed in flames for several seconds before it stopped, and then it would take several more seconds for the fire trucks to reach the plane even if they are waiting for it next to the runway. It took them 1/2 hour to extinguish the fire.

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  16. #16
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    7,037

    Default

    Two new videos uploaded in AvHerald.

    One showing the vary rough final bounce (corded from a TV, so not good quality, but it can still be appreciated that it was really rough and, while I would understand the landing gear failing, I don;t understand 50%+ of the people on board dying).

    The second one is the final seconds of the landing roll recorded from the cabin by a pax sitting next to the wing. You can see the fire out of the window and the cabin staring to fill up with smoke. Perhaps it was the smoke, not the fire, what initially disabled the passengers who could then not escape.

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  17. #17
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    7,037

    Default

    A better view of the bounce and start of the fire

    https://twitter.com/RALee85/status/1125 ... 97/video/1

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  18. #18
    Senior Member Evan's Avatar
    Join Date
    Jan 2008
    Posts
    6,786

    Default

    Quote Originally Posted by Gabriel View Post
    A better view of the bounce and start of the fire

    https://twitter.com/RALee85/status/1125 ... 97/video/1
    Maybe it's just because the video quality is so bad, but it appears to me that the main gear is missing after the first bounce and that the plane coms down hard on the engine nacelles just before the fuel cloud and fire appear. The SSJ has those long engine pods that extend further under the wing. Perhaps they breached the tanks.

    https://edition.cnn.com/2019/05/05/e...ire/index.html

  19. #19
    Administrator Alex - Spot-This !'s Avatar
    Join Date
    May 2005
    Location
    Switzerland
    Posts
    4,455

    Default

    Yes, main gear went through the wings and tanks after first hard contact, setting everything on fire.

  20. #20
    Senior Member 3WE's Avatar
    Join Date
    Jan 2008
    Posts
    5,142

    Default

    Quote Originally Posted by Gabriel View Post
    The fire should not have gone into the cabin so easily. Unless the landing was harder than I think and the fuselage itself broke.
    I think the landing was harder than you think.

    Evidence: A very large fire that went into the cabin.

    If you hit hard enough, there's things besides the landing gear that rupture fuel tanks. (Evan's nacelles included)

    Quote Originally Posted by Gabriel View Post
    Perhaps it was the smoke, not the fire, what initially disabled the passengers who could then not escape.
    ...or impact injures...The 90-second evacuation is usually done with healthy, mobile folks who are mentally prepared, in a not_smoke-infested cabin, AND not really in danger, since it's usually a simulation.
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •