Icon A5.. another crash Jul 27

PaulS said:
Boaters have a tough time with this also. I don't know how many small boat captains think they need to increase speed to maintain steerage with a current from aft.
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Apples and oranges, how often do you fly with negative airspeed? Lots of boats handle very poorly when the current is moving faster than the boat.
 
I remember in the Kirchner manual, he covered air masses and how the airplane became part of the movement of the airmass as soon as it took off. In other words as soon as you take off, the airplane moves in the same direction as the airmass in relation to the ground. As far as the airplane is concerned it behaves as it is does in still air. You compensate for this by adjusting your ground track. Not sure if the newer manuals and the stuff from the FAA cover this. I looked quickly, but didn't see it in the FAA manuals.
 
Bacho said:
Apples and oranges, how often do you fly with negative airspeed? Lots of boats handle very poorly when the current is moving faster than the boat.
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I rest my case, movement relative to land is not what I was talking about.
 
PaulS said:
Yes, but it didn't have to be that way, even after he lifted off.
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Personally I don’t think he left himself enough room to do anything but crash. He certainly had enough room to water taxi to where the camera boat was and nearly double his margin for “runway” length and chose not to do it.
 
Bacho said:
Apples and oranges, how often do you fly with negative airspeed? Lots of boats handle very poorly when the current is moving faster than the boat.
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Thinking about this, I think the difference is a boat is “trapped” between two different frames of reference.

I mean, anything below the waterline essentially has the moving mass of water affecting it. But anything above the waterline has to deal with the effects of a moving - or stationary - air mass. Perhaps that’s what leads to the poor handling referenced above?
 
Martin, you don't get it, but don't feel bad for not "getting it", as I once had a CFI that during a biennial flight review argued with me about the same thing while I did turns around a point in high winds, and he kept saying I needed to adjust my throttle lower on the upwind side, and higher on the downwind side, to make up for increase/loss in airspeed (which is clearly wrong). When I finally asked him if we did turns around a floating hot air balloon, instead of turns around a point, how my airspeed would change: it was his "ah ha" moment, and he finally got it too.
 
PeterNSteinmetz said:
When you “give up crabbing” that requires turning and accelerating the boat. Similarly, if you turn a plane in the air as it is flying, no matter which way the air is traveling, that also requires some acceleration.
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Navy guys don’t care for any references to crabs


Sent from my iPad using Tapatalk
 
PeterNSteinmetz said:
Personally, most discussions I am actually interested enough in to participate in, I don’t find it very interesting to debate different authorities. IMO, better to stick to facts and reason about the subject.
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Thanks, my whole point was I think Icon is playing a dangerous game with their marketing, and I'm not alone in thinking that. I'm not sure what the point was in claiming that as an appeal to authority fallacy.. It wasn't meant to be that deep, just that their whole brand is playing a risky game. Whether this crash, by an Icon employee, was a sign of a dangerous culture there, or just a fluke, can be up for debate.. we'll never know exactly what the actual / honest PIC's decision making skills, motivations where, etc. The consensus however from this group seems to be that they would not have attempted that take off.. so why did the Icon guy attempt it? A belief in an infallible product? An illusion that it's just a toy so no real risk? A pressure to sell another product and this was his only opportunity for scheduling / etc to fly it? Simply having an off day?

PeterNSteinmetz said:
When you “give up crabbing” that requires turning and accelerating the boat. Similarly, if you turn a plane in the air as it is flying, no matter which way the air is traveling, that also requires some acceleration.
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Any change in motion is by default "acceleration" - so turning the aircraft will require an acceleration, yes. What I think people are missing here, is (assuming no gusts), it that the aircraft only flies with reference to the air itself. It does not know what the ground is doing. The plane moves along with the whole air mass. Even in a crosswind the plane is flying "straight" relative to the air, unless you are slipping

PaulS said:
Boaters have a tough time with this also. I don't know how many small boat captains think they need to increase speed to maintain steerage with a current from aft.
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This always puzzled me too... and I think it's due to the illusion. A sailor traveling at 3 knots over the water but in a 7 knot downstream current will see the land and buoys going by at 10 knots (a lightning fast speed for a little sailboat).. relative to the ground and buoys the steering inputs will feel sluggish. They'll move the tiller but find themselves still heading towards the rock or ledge, so people throttle up the engine.. but it only exacerbates the illusion. Like the other poster after you incorrectly observed, there's some kind of impression that the water is "pushing" against the rudder or something so it is less effective. As with the airplane, the boat has no idea what the ground is doing.. it simply travels with it's system. Traveling up stream people suddenly find that their boat is extremely responsive.. even though their speed over the water is the same their motion to the shore and buoys is slower and they suddenly become experts at docking, avoiding rocks and buoys, etc.
 
Tantalum said:
This always puzzled me too... and I think it's due to the illusion. A sailor traveling at 3 knots over the water but in a 7 knot downstream current will see the land and buoys going by at 10 knots (a lightning fast speed for a little sailboat).. relative to the ground and buoys the steering inputs will feel sluggish. They'll move the tiller but find themselves still heading towards the rock or ledge, so people throttle up the engine.. but it only exacerbates the illusion. Like the other poster after you incorrectly observed, there's some kind of impression that the water is "pushing" against the rudder or something so it is less effective. As with the airplane, the boat has no idea what the ground is doing.. it simply travels with it's system. Traveling up stream people suddenly find that their boat is extremely responsive.. even though their speed over the water is the same their motion to the shore and buoys is slower and they suddenly become experts at docking, avoiding rocks and buoys, etc.
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This is a fascinated thread that is giving me a headache, but i'll chime in.

Steady river flow assumed. The difference with airplanes and boats is that boats do not adhere to the need for coordinated turn.. well at least not to the same degree. If you are going to make a quick, skidding change of direction(180) in a small power boat, you are going to lose forward(bow of the boat) momentum for a period of time. While this is a different phenomena than losing speed because you are "pushed" by the current the end result is loss of speed in a turn(just for completely different reason). Maybe this is what that Martin guy was talking about. Same would happen if you are doing full 180 snap skid turn in the plane, but no-one would dare to do it outside of aerobatics. People do it on small boats all the time. I suspect that this what causes boaters to misunderstand what is happening

An important note here: I am not at all implying that boat or plane cares about ground or that you will significantly lose your forward speed in a normal coordinated turn.

I should probably add that it still doesn't make any difference here what the wind/current is doing, but it creates certain illusions in boats when one is close to the shore
 
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Tantalum said:
... Whether this crash, by an Icon employee, was a sign of a dangerous culture there, or just a fluke, can be up for debate...
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Where are people getting the notion that this incident involved an Icon employee? I don't see any mention of that other than the owner, who was trying to sell his airplane, was maybe once referred to as a "salesman"
 
genna said:
This is a fascinated thread that is giving me a headache, but i'll chime in.

Steady river flow assumed. The difference with airplanes and boats is that boats do not adhere to the need for coordinated turn.. well at least not to the same degree. If you are going to make a quick, skidding change of direction(180) in a small power boat, you are going to lose forward(bow of the boat) momentum for a period of time. While this is a different phenomena than losing speed because you are "pushed" by the current the end result is loss of speed in a turn(just for completely different reason). Maybe this is what that Martin guy was talking about. Same would happen if you are doing full 180 snap skid turn in the plane, but no-one would dare to do it outside of aerobatics. People do it on small boats all the time. I suspect that this what causes boaters to misunderstand what is happening

An important note here: I am not at all implying that boat or plane cares about ground or that you will significantly lose your forward speed in a normal coordinated turn.
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That's about the only way I could fathom Martin's theory making any sense. If you were to go from flying upwind at the edge of a stall, then initiating a turn downwind at such a high rate that inertia wasn't enough to accelerate the mass of the the aircraft instantaneously to keep the wings from losing lift and causing a stall. A normal coordinated turn allows the inertia to bring the aircraft speed back in check when transitioning from upwind to downwind when on the borderline of a stall.

As far as most powerboats and speed against a following current, most of the ill-handling is a result of the hull design and the stern of the boat typically being a flat wall for the water to push against. It's sort of like trying to ride a tricycle in reverse. The benefit of having the bow cutting through the water (providing stability) is lost and handling gets sloppy. The outdrive by itself isn't usually an effective rudder with little thrust being provided, so the sloppy handling is only exacerbated.
 
Silvaire said:
Where are people getting the notion that this incident involved an Icon employee? I don't see any mention of that other than the owner, who was trying to sell his airplane, was maybe once referred to as a "salesman"
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Post 242

Does it change the story that much though if it's not an Icon employee? My whole point is there's a cultural issue with the image Icon is pushing.
 
SoonerAviator said:
That's about the only way I could fathom Martin's theory making any sense. If you were to go from flying upwind at the edge of a stall, then initiating a turn downwind at such a high rate that inertia wasn't enough to accelerate the mass of the the aircraft instantaneously to keep the wings from losing lift and causing a stall. A normal coordinated turn allows the inertia to bring the aircraft speed back in check when transitioning from upwind to downwind when on the borderline of a stall.
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But that's because of the usual laws of physics. Not because of some relative wind angle. The plane still won't have any idea its in a crosswind or not. Martin's post point blank said "the plane is pushing against the crosswind flying relative to the ground when in the pattern" and claimed that a boat crossing a river and turning downstream will experience a loss in waterspeed to 0 mph before.
 
Tantalum said:
But that's because of the usual laws of physics. Not because of some relative wind angle. The plane still won't have any idea its in a crosswind or not. Martin's post point blank said "the plane is pushing against the crosswind flying relative to the ground when in the pattern" and claimed that a boat crossing a river and turning downstream will experience a loss in waterspeed to 0 mph before.
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Perhaps what Martin is trying to convey is an accelerated stall? Or at least getting close to it and feeling it? Honestly, I have no idea. I'm just trying to understand the logic behind these statements.
 
I think flying seaplanes is a lot of fun. Part of that is because you are often close to the water, which is more dangerous than cruise flight at altitude. There is a reason that flying seaplanes requires a separate rating. And I agree that Icon’s marketing appears to de-emphasize this.
 
FastEddieB said:
Thinking about this, I think the difference is a boat is “trapped” between two different frames of reference.

I mean, anything below the waterline essentially has the moving mass of water affecting it. But anything above the waterline has to deal with the effects of a moving - or stationary - air mass. Perhaps that’s what leads to the poor handling referenced above?
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If the current is moving faster than the boat, the boat has negative water speed and is moving sternward in the water, even though it may be moving forward relative to land. I don't know any boat that handles well in reverse....
 
genna said:
Perhaps what Martin is trying to convey is an accelerated stall? Or at least getting close to it and feeling it? Honestly, I have no idea. I'm just trying to understand the logic behind these statements.
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Who knows... I doubt he's a troll, and truth be told I felt a little bad considering the kind of welcome a brand new poster got. But there was no real way I (or seemingly many here) could make sense of it. What really got me was the idea that planes flying straight and level and coordinated are actively "pushing against" a crosswind

We are also unfortunately many times limited by our language and linguistics, so conveying a point can be challenging, and given the internet and our pedantic nature things get pulled out of context, like the poster who assumed I took umbrage with all modes of amphibious flying
 
I think if you show up with bad aerodynamics knowledge in an aviation group and state that the bad info is a fact, you’re pretty much guaranteed a bad day. Newbie or not.

Heck, I’ve had my ass handed to me here about aerodynamics. We have some smart fellers here. And I are just a dumb pilot.
 
An airplane is not flying against a crosswind, it is flying straight through the air perfectly coordinated. Because the air mass is in motion relative to the ground the airplane's heading and ground track are not going to be the same. This is where Martin went off the rails because he has mixed up his inertial references. He believes that when turning from upwind to downwind there is an acceleration because his ground speed has increased but this is false. If you are flying at 100 kts directly into a 10 kt wind your ground speed is 90 kts. So, in reference to the ground you already have that 10 kts in the downwind direction. When you turn 180 degrees you're still going 100 kts through the air and your groundspeed is 110 kts but you have not accelerated because you are airborne and your inertial reference has nothing to do with the ground below.

I hope he can wrap his head around this and stop posting false information.
 
denverpilot said:
I think if you show up with bad aerodynamics knowledge in an aviation group and state that the bad info is a fact, you’re pretty much guaranteed a bad day. Newbie or not.

Heck, I’ve had my ass handed to me here about aerodynamics. We have some smart fellers here. And I are just a dumb pilot.
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Humans in general are pretty bad at abstract concepts. So I get that, invisible high speed moving masses are hard to grasp in particular
 
SoonerAviator said:
If you were to go from flying upwind at the edge of a stall, then initiating a turn downwind at such a high rate that inertia wasn't enough to accelerate the mass of the the aircraft instantaneously to keep the wings from losing lift and causing a stall.
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Even couched like that, I think it’s still in error. Both before and after the turn, the plane is moving along in the same parcel of air. Relative to that, there’s no change in inertia involved.

Try doing slow flight, even at the edge of a stall, in a strong wind and do some 360° turns. You will not feel any acceleration or deceleration*. I predict in smooth air a plumb bob would confirm that.


*Though at low altitude you will certainly see some acceleration and deceleration relative to the ground, which can give a false impression.
 
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Tantalum said:
Who knows... I doubt he's a troll, and truth be told I felt a little bad considering the kind of welcome a brand new poster got.
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Same here.

But there was no real way I (or seemingly many here) could make sense of it. What really got me was the idea that planes flying straight and level and coordinated are actively "pushing against" a crosswind...
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I think he was talking about the fact that when you are on the crosswind leg of a traffic pattern, if there is a wind aligned with the runway, then you are going to have to crab into the wind if you want your pattern to be perfectly rectangular. Crabbing into a crosswind can be thought of as using a portion of the thrust to resist the effect of the crosswind.

As for the rest of what he was trying to say, I'm not sure.
 
I do, however, think that in this particular crash the turn "downwind" may have contributed to stall. Plane looked pretty slow and I can assume that it was close to the stall before the turn already. It looks like a steep enough bank to accelerate the stall somewhat. Additionally, while steady wind wouldn't make any difference, this specific case probably has mechanical turbulence from the tree line and possibly a small wind sheer as he was transitioning from a protected lake(below tree line) to just above it. So this is not likely a "steady" wind condition. Possibly just enough to stall one wing
 
Tantalum said:
Who knows... I doubt he's a troll, and truth be told I felt a little bad considering the kind of welcome a brand new poster got. But there was no real way I (or seemingly many here) could make sense of it. What really got me was the idea that planes flying straight and level and coordinated are actively "pushing against" a crosswind

We are also unfortunately many times limited by our language and linguistics, so conveying a point can be challenging, and given the internet and our pedantic nature things get pulled out of context, like the poster who assumed I took umbrage with all modes of amphibious flying
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It’s almost impossible to explain it in posts. I find it uncomfortable that people with a cert don’t get it though.
 
FastEddieB said:
So, the “downwind” was not a contributor. Gusts may have been. Two very different things.
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Well the gust is not random. it is probably in the direction of normal wind. so it will effectively instantaneously lower(after the turn) your airspeed for duration of the gust. This is why we add airspeed for landing or take-off in gusty conditions.
 
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... "lower" because you are now traveling in the direction of wind/gust. or in this case not quite in the same direction, hence different effect on 2 wings=stall/spin
 
to put it differently, had he performed take off with crosswind and then turned upwind to climb over the trees, the result may have been different as wind speed increase over the tree line likely given him extra lift(at least temporarily)
 
genna said:
to put it differently, had he performed take off with crosswind and then turned upwind to climb over the trees, the result may have been different as wind speed increase over the tree line likely given him extra lift(at least temporarily)
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Unless, as someone pointed out earlier in the thread, there was a downdraft coming over the ridge...... it’s possible.
 
As I said earlier the "downwind" aspect could be a factor due to the proximity to the ground and the powerful visual force the pilot encounters if his attention is focused on it rather than the instruments and I think the Icon, with it's "sportscar" like panel despite having an AOA, is mostly flown that way.
 
Perhaps if Martin, since he seems to be into physics, would just use a vector diagram, he would see how it all adds up, no energy is added and therefore it is impossible for there to be an acceleration.
 
Salty said:
Unless, as someone pointed out earlier in the thread, there was a downdraft coming over the ridge...... it’s possible.
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correct. no way to really know what direction of wind was over the tree line either. ground wind and wind aloft(even just over trees) are not the same thing a lot of times. It's a lot of speculation here. This is why i qualified my assessment as "may have"
 
Silvaire said:
Perhaps if Martin, since he seems to be into physics, would just use a vector diagram, he would see how it all adds up, no energy is added and therefore it is impossible for there to be an acceleration.
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I think the source of the error in thinking however is that the “wind” is a source of energy in this equation. Until that thought is accepted as wrong, the result will be wrong.

Wind is a source of energy as related to ground movement, and so people think it transfers to this discussion. That’s the fallacy.
 
Should the empennage break that easily without a direct impact?
 
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Rein Hart said:
The tree hit the wing not the tail.
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It looked to me like the wing hitting yawed the plane and then the tail caught the tree even harder than the wing.
 
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