Announcement

Collapse
No announcement yet.

Snowbird jet crash in Kamloops, B.C., Canada

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Schwartz
    replied
    Originally posted by Gabriel View Post
    It was not an "engine failure" accident, it was a stall-spin accident (yes, the engine had an issue and perhaps fully fail, but that doesn't cause the airplane to stall and spin).

    In that regards, it is similar to the Pilatus accident of the other thread.

    It doesn't stop to surprise me haw pilots of all experience levels still fall in this trap. These were pilots of the aerobatic demonstration team of a major western air force, not rookies.
    Yes, elite pilots from the air force. In an easy to fly aircraft designed for training. I have no explanation other than poor split second decision when there was no room for error.

    Leave a comment:


  • Schwartz
    replied
    Originally posted by Evan View Post

    I was assuming that the climb was part of the show and that the engine issue occurred during that climb, but now I understand that this was an escape manuever following an engine issue during takeoff, perhaps a compressor stall. The initial bank seems like an intentional turnback, which, at such low airspeed, would be risky. Then it appears to me that a left wing stall occurs, the pilots regains enough control to roll it back to the blue, at which point there is nothing left to do but eject. So, yes, the error might be the initial turn back in that climb attitude so close to stall.
    OK, let's straighten out several things first:

    Kamloops is not a very populated city. It is tiny at 100K population. Second, this was not a show. The two planes were transiting to their next destination in the northern US presumably for a show. The deceased was a public affairs officer who was transiting with the group. The pilot survived with serious, but non life-threatening injuries.

    There will be no complaints about shows over the city because of this. The neighbourhood was directly on the left side at the end of the runway and it wasn't a show.

    At first, my assumption was the pilot aimed the aircraft into a particular crash spot, but looking at the location of the airport, the river on the right side would have been a much better place to ditch if that was the intent.

    I now tend to agree with Gabriel, that the pilot was attempting to maneuver -- possibly a left turn to return to the airport right behind them -- and stalled. The aircraft is a side-by-side two seater, and you can see the ejections were not simultaneous. I don't know how ejection works in those side by side planes if it is staggered automatically or if they each have to trigger their own ejection. Either way, I suspect the pilot ejected first and thus survived landing in the yard. I believe one person ended on a roof and the other in a yard. Given the short distance involved the roof could also have shortened the time for the chute to open.










    Leave a comment:


  • 3WE
    replied
    Originally posted by Gabriel View Post
    Why did he also turned left increasingly tight? I don't know.
    It's plausible that he was distracted with the problem and the plane lost speed "much faster than he ever imagined" since folks almost never deal with truly zero thrust.

    It's plausible that there was a control problem ALONG WITH the suggested engine problem.

    A deliberate stall as a method to address the problem/quickly return to the airport...very unplausible...to me, at least.

    Edit: I do not think we have ruled out a meteor strike either.

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    Exactly what was a risky maneuver?
    I was assuming that the climb was part of the show and that the engine issue occurred during that climb, but now I understand that this was an escape manuever following an engine issue during takeoff, perhaps a compressor stall. The initial bank seems like an intentional turnback, which, at such low airspeed, would be risky. Then it appears to me that a left wing stall occurs, the pilots regains enough control to roll it back to the blue, at which point there is nothing left to do but eject. So, yes, the error might be the initial turn back in that climb attitude so close to stall.

    Leave a comment:


  • vaztr
    replied
    Perhaps he didn't want to keep flying 'straight' if that was over houses, so was trying a 'stall turn' (hammerhead???) in order to make it back to the field??

    Leave a comment:


  • Gabriel
    replied
    Originally posted by Evan View Post
    I question that. If the pilot were attempting a maneuver that puts the airspeed just below stall warning and thrust is suddenly lost in that attitude I think it's possible that a stall could be unavoidable simply because there is insufficient time to react and for the control inputs to achieve the needed results.
    You can (temporarily) fly at less than the stall speed (quite less indeed) and not stall.
    In the same way that you stall faster when you are pulling more than 1G, you stall slower when you push less than 1G. At zero G you don't stall.
    The reduction of AoA is almost instantaneous, you really don't need "time for the control inputs to achieve", and regarding "time to react", not reacting (i.e. not pulling up) is a good start.

    I suspect that this was a risky maneuver for an aircraft with relatively lousy climb performance.
    Exactly what was a risky maneuver?

    It seems that the plane had an engine issue shortly after take-off when still flying low and accelerating in close formation, and at that point the pilot pulled up to exchange the excess speed (above glide) for altitude. That's the standard SOP for an engine failure during take-off in this plane and in this team.

    Why did he also turned left increasingly tight? I don't know.

    When I am talking about the stall I am not talking about what happened down there where the engine had an issue and the pilot initially pulled up. I am talking about what happened up there where they apparently lost control. It could be that the plane started to roll inverted (for some reason) and the pilot completed the aileron roll to put blue over brown in order to eject.

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post

    I am not saying recover instead of eject, not at the point that they ejected. A stall is never unavoidable.
    I question that. If the pilot were attempting a maneuver that puts the airspeed just below stall warning and thrust is suddenly lost in that attitude I think it's possible that a stall could be unavoidable simply because there is insufficient time to react and for the control inputs to achieve the needed results. I suspect that this was a risky manuever for an aircraft with relatively lousy climb performance.

    However, you might have some particular insight into the handling characteristics involved. Like the Tomahawk, the Tutor was designed for spin recovery training and thus features a similar t-tail empennage. It enters spins easily. It is also inherently stable, so less agile in manuevering.

    Leave a comment:


  • 3WE
    replied
    Originally posted by Gabriel
    Originally posted by Sort of ATL
    ...mignt not have been JUST an engine failure...
    ...But why would that be a particularly plausible theory?...
    Plausible because pilots who are a hell of a lot better trained and smarter than you rarely take an engine-out plane up into a sharp pull up all the way to a spin. (No I didn't say never because WE certainly beat the exceptions to death).

    I will not speak for ATL but I will give the pilot the benefit of doubt until there is evidence otherwise.

    You are becoming Evan whom defaults to 'stupid cowboy improvisational monkey pilot most likely screwed up.

    I would think they had a $hit pot of energy to do a Bob Hoover WITHOUT the two loops and a roll and land, and the skills to execute it.

    Originally posted by Gabriel
    At this time, we can't discard anything.
    Please note that "we" was not italicized in your original post, and try to avoid similar future mistakes. Thanks in advance.


    Leave a comment:


  • Gabriel
    replied
    Originally posted by ATLcrew View Post
    Keep in mind this might not have been just an engine failure, there might have been control system issues, too, particularly with regards to pitch.
    At this time, we can't discard anything. But why would that be a particularly plausible theory? In general, engine failures don't come associated with pitch control system issues. Then you had Sioux City.

    Leave a comment:


  • ATLcrew
    replied
    Keep in mind this might not have been just an engine failure, there might have been control system issues, too, particularly with regards to pitch.

    Leave a comment:


  • Gabriel
    replied
    Originally posted by Evan View Post

    Are you serious?

    This goes from routine to critical in two seconds at what is probably the performance limit of the aircraft, nose-high attitude in a low speed bank. It appears that a wing stall occurs immediately (or it's very high AoA with insufficient aileron effect) and it rolls inverted but the pilot manages to rolls it back to level, under control (in a dive attitude) and immediately ejects. Was there sufficient altitude to recover instead of eject? Maybe, but why gamble on it?.
    I am not saying recover instead of eject, not at the point that they ejected. A stall is never unavoidable.

    If the aileron roll was intentional as ATL said, then I agree with him. In that case the entry in the aileron roll was probably not done at the correct speed/altitude (they were too slow and low).
    But if it the result of a stall as I suspected (one wing stalling first), again, the stall is always avoidable, they could have lowered the nose, not_stall_and_spin, and eject from a controlled flight.

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post

    Keep the airspeed in check and if the stall warning goes off, reduce AoA. Didn't you see the training video in the other thread?

    And eject when still under control (a luxury you don't have in the civilian world, not even in the Cirrus at this altitude).
    Are you serious?

    This goes from routine to critical in two seconds at what is probably the performance limit of the aircraft, nose-high attitude in a low speed bank. It appears that a wing stall occurs immediately (or it's very high AoA with insufficient aileron effect) and it rolls inverted but the pilot manages to rolls it back to level, under control (in a dive attitude) and immediately ejects. Was there sufficient altitude to recover instead of eject? Maybe, but why gamble on it?.

    Leave a comment:


  • Gabriel
    replied
    Originally posted by Evan View Post
    Well, yes actually it was a ground impact accident. Stall and spin don't cause the airplane to destruct. Hitting the ground does.
    Are you serious?

    What I understood (perhaps incorrectly) is that this occurred immediately after takeoff, when one plane continued to accelerate in a moderate climb while the accident aircraft went into a steep climb at the expense of airspeed. The Tutor does not have the immense thrust/weight ratio of fighter aircraft, not even close. A sudden loss of thrust at that moment, when you must be close to stall, at such low altitude... what can you do to recover?
    Keep the airspeed in check and if the stall warning goes off, reduce AoA. Didn't you see the training video in the other thread?

    And eject when still under control (a luxury you don't have in the civilian world, not even in the Cirrus at this altitude).

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    It was not an "engine failure" accident, it was a stall-spin accident (yes, the engine had an issue and perhaps fully fail, but that doesn't cause the airplane to stall and spin).
    Well, yes actually it was a ground impact accident. Stall and spin don't cause the airplane to destruct. Hitting the ground does.

    What I understood (perhaps incorrectly) is that this occurred immediately after takeoff, when one plane continued to accelerate in a moderate climb while the accident aircraft went into a steep climb at the expense of airspeed. The Tutor does not have the immense thrust/weight ratio of fighter aircraft, not even close. A sudden loss of thrust at that moment, when you must be close to stall, at such low altitude... what can you do to recover?

    Leave a comment:


  • ATLcrew
    replied
    Originally posted by Gabriel View Post
    It was not an "engine failure" accident, it was a stall-spin accident (yes, the engine had an issue and perhaps fully fail, but that doesn't cause the airplane to stall and spin).
    I'm not sure about that, not based on the video anyway. Those look like pretty controlled maneuvers, including that aileron roll towards the end. In fact, it looks like they avoided that "trap" pretty well, there just wasn't the altitude to do much else.

    Leave a comment:

Working...
X