Icon A5.. another crash Jul 27

Ryanb said:
Time to stop. Not one member agrees with you and your credibility to the forum is zero. Sorry but you need further education on this subject.
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Further education is entirely dependent on being teachable. This case might be unsalvageable.
 
Non-trolls usually strongly object to accusations of trolling. ;)
 
Ryanb said:
Time to stop. Not one member agrees with you and your credibility to the forum is zero. Sorry but you need further education on this subject.
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NO, NO! Don't stop!

It's pouring rain, I have nowhere to go, and I was about to make a fresh batch of popcorn and crack open a bottle. I'm looking forward to this evening's entertainment.
 
PaulS said:
You may be on to something here, if you wet your finger and stick it out the window, the wind only comes from upwind.
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Well, except if you were to instantaneously switch directions, then it would come from downwind.

:rolleyes:
 
He's right, it's why my hang glider falls out of the sky when the wind stops.:D:D:D:D:D:D
 
Martin Renschler said:
What I am referring to is inertia (V=M*A). If you fly a square pattern and crab on your cross wind you have no velocity in the direction of the wind. If you then turn downwind, you need to accelerate the plane in the direction of the wind. Until your plane has reached wind speed plus relative speed in that direction, you have less lift.
This is why ground speed matters in this case.
I do agree that if you blindly fly a circle without reference to any ground pattern, the wind has already accelerated you in the direction of the wind. However that is a different case than flying a pattern.
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If you're flying a rectangular pattern, then you're flying a ground-reference maneuver, so in that scenario, yes, the ground matters. Since you're crabbed on crosswind, you have to turn more than the 90 degrees by some amount, which you would not have to do if there were no wind. That means that you will either have to stay in the turn longer, or bank more steeply, or some combination of the two. Assuming you hold altitude and don't add power, you will lose more airspeed in the turn than you would if there were no wind.

This does not, however, mean that you have to do the analysis using a reference frame that is attached to the surface of the earth. When the airplane's path is drawn in a reference frame that is moving with the air mass, it will not appear as a rectangular pattern, and the amount of turn will have to exceed 90 degrees by the same amount as in the previous paragraph.

The effect of ground reference on the pilot's actions were previously acknowledged in general terms earlier in the thread.
 
MooneyDriver78 said:
I’m waiting for the plane on a treadmill discussion.....


Tom
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What if the treadmill were on a hot air ballon that was released from a boat on a river?
 
PaulS said:
You may be on to something here, if you wet your finger and stick it out the window, the wind only comes from upwind.
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Duh. How do you think the aliens in the weather balloons determine winds aloft?
 
Martin Renschler said:
..."Turning downwind" is when you turn from base to final....
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I hope you meant turning from crosswind to downwind. Otherwise, you'd be landing with a tailwind. :eek2:

...Here is a thought experience: Think flying upwind with the same speed as the wind. You are hovering over a point. Lets say you can instantly turn downwind. What is the relative wind speed then? Does your plane need to accelerate to stay in the air?
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Let's pick a nice round number of 100 knots true airspeed.

Changing the ground velocity from 0 knots to -200 knots would be a change of -200 knots.

If there were no wind, changing the ground velocity from +100 knots to -100 knots would be a change of -200 knots.

So in that scenario, the amount of acceleration required is the same regardless of whether there is wind or not.
 
When teaching ground reference maneuvers, I would point out how they all use the same elements.

What I mean is that a rectangular pattern can be seen as a turn about a point, broken roughly into quarters with some straight-and-level crabbed flight between each quarter.

Martin has posted that a traffic pattern is somehow fundamentally different from a turn about a point or crabbed flight. It’s not.
 
I'm still not sure what F=MA has to do with his claims in the first place...

Martin, you should probably also take into account some relativistic concerns in your flight planning. Remember that because you are moving relative to the ground, there will be a slight time dilation effect causing you to arrive slightly off your planned ETA.

Ok, very slight.
 
There is no educating the uneducable. As the poster in my office says, "Science doesnt give a s*** about your beliefs". Carry on. I'll stick to science. It's safer and more predictable.
 
What about helicopters? It's already impossible for them to fly, no matter what the winds aloft are.
 
PaulS said:
You may be on to something here, if you wet your finger and stick it out the window, the wind only comes from upwind.
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DaleB said:
Well, except if you were to instantaneously switch directions, then it would come from downwind.

:rolleyes:
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Actually if you rotate your hand 180 degrees, it’s obvious the wind switched direction 180 degrees since it’s now cooling the back of your finger, not the front. Q.E.D. :confused:

Cheers
 
If I turn on my AC and point my overhead vents backwards can I counteract tailwinds and F=M*A?
 
What about a hot air balloon? If you face one direction you are moving with the wind in your face, and if you spin around in the basket you are moving with the wind in your face...wait...what wind?
 
Martin, do you announce on the radio when you make that downwind base to final turn? I ask because the rest of us are coming the opposite direction and would appreciate the warning.
 
Matthew said:
What about a hot air balloon? If you face one direction you are moving with the wind in your face, and if you spin around in the basket you are moving with the wind in your face...wait...what wind?
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So when flying turns around a balloon, is the bank angle greatest for the upwind or the downwind portion?
 
Martin Renschler said:
Misunderstanding of what I was trying to say. I was referring to "turning downwind" rather than making a circle into the medium air. "Turning downwind" is when you turn from base to final. You are flying a pattern which is based on ground reference. Totally different physical case than making a blind circle in the air.
Here is a thought experience: Think flying upwind with the same speed as the wind. You are hovering over a point. Lets say you can instantly turn downwind. What is the relative wind speed then? Does your plane need to accelerate to stay in the air?
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Martin-
Welcome to PoA.
I've actually done the hovering over a point thing. My flight instructor had me practice slow flight in a C-152 in a steady strong wind, and we hovered over the Flemington Circle in New Jersey for several minutes. It was as if the Almighty let me sit in his easy chair and look over creation for a while. We then turned 180 degrees and headed back to Solberg. No issues. After the turn, we resumed normal flight.

When we do ground reference maneuvers, we change the amount of bank in our turns to compensate for us being in a moving body of air.

Is it possible you are thinking of what happens in a microburst, where the wind actually does make an abrupt change in direction and speed? Aircraft can take advantage of wind gradients, see: https://en.wikipedia.org/wiki/Dynamic_soaring
However, not so much a steady breeze.
 
Cap'n Jack said:
Martin-
Welcome to PoA.
I've actually done the hovering over a point thing. My flight instructor had me practice slow flight in a C-152 in a steady strong wind, and we hovered over the Flemington Circle in New Jersey for several minutes. It was as if the Almighty let me sit in his easy chair and look over creation for a while. We then turned 180 degrees and headed back to Solberg. No issues. After the turn, we resumed normal flight.
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Someone somewhere probably still has a video of me flying a Cub. The winds aloft at Boerne Stage were strong enough that I was able to take off into the wind maintain my heading throttle back, drift backwards over the ground while flying at about 40 to 45 mph indicated and I landed without ever changing my heading on the same runway... The scariest part was actually taxiing back.
 
Martin Renschler said:
If you cross a river crabbing so you cross the river in a right angle and then you decide to give up crabbing and go downstream, for sure everyone in the boat will feel the acceleration from 0 mph downstream to the rivers speed plus the boat's speed.
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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.
 
Tantalum said:
Referencing the editor of (one of) the largest aviation magazine in the world as a point that my views on Icon having an inappropriate marketing strategy are not at all fallacious. What would have been fallacious is if I referenced some random person.. the media often does this, a professor of english will weigh in on military matters
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Any time one tries to argue that a certain point is true because some other person said so, that is, from the perspective of a logical argument about that point, an appeal to authority. If one is substituting that and presenting it in response to specific facts or logical reasoning, it does strike me as a fallacy.

People often do this casually in discussions, where they aren’t trying to make some specific point, as a way to sidestep actually debating the facts and reasons and it is often casually accepted that way.

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.
 
Turning sowing DI
Martin Renschler said:
In most postings of this thread, there is a big misunderstanding of plain physics!
Yes, the plane flies in air and generally / eventually everything is relative to air.
However, when it comes to acceleration of the mass of the airplane only the reference to ground matters!!!
The moment the plane turns downwind, it needs to accelerate to its new ground speed. That energy needs to come from somewhere (namely from the difference between thrust and drag). It will take a few seconds and during this time, drag and lift is reduced.
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i believe I agree with you.
It’s sort of like a slow wind shear. If the airplane cannot keep up with the change in wind....
 
Martin Renschler said:
If you fly the pattern, you are not "traveling with the air mass" you are flying a straight line with ground reference. You are actually holding against the traveling air masses.
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Please stop. Watching this thread is like watching some guy at a blackjack table doubling down on a pair of 2's when the dealer is showing a 10.
 
Kritchlow said:
Turning sowing DI

i believe I agree with you.
It’s sort of like a slow wind shear. If the airplane cannot keep up with the change in wind....
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No we are not talking wind shear man!
 
donjohnston said:
Please stop. Watching this thread is like watching some guy at a blackjack table doubling down on a pair of 2's when the dealer is showing a 10.
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This thread is conversions on multiple subjects. I think he has the right idea, but the subject is irrelevant to the OP.

We can all agree that flying in the pattern is ground referenced.the airplane is flying in the “current” of the wind. We make corrections in flight to adjust the plane to conform to ground references. Those adjustments change based on the strength of the wind. None of that has anything to do with the OP. A plane stalling and falling out of the sky has nothing to do with ground speed.

On the mass of the aircraft changing direction, yeah it takes extra energy to change the direction of moving object with mass. That has nothing to do with the direction of flight relative to the wind direction. We hardly notice this for the reason below.

We all know an aircraft suffers a change in the center of lift when banked. This is why additional pitch and throttle are needed to maintain altitude and airspeed when turning. The direction of wind has nothing to do with that either.

The only reason the wind direction comes into play is when its unstable. When the aircraft is close to stall speed, the wind gusts or lulls can make the difference between flying and not flying.

This crash involved low airspeed, low altitude, unstable breeze, no reserve power and a change in course all at once.
 
This crash involved pitching the nose up when it should have been pitched down. A quick glance at the airspeed indicator would have given the information needed in this circumstance. The AOA is a bonus.
 
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.
 
FastEddieB said:
No argument there.

But human psychology comes into play. Hopefully, how and when to abort a takeoff was covered in training. But after 100’s or even 1000’s of successful takeoffs, expectations can be very high that a successful takeoff will be the end result once the throttle is pushed forward. It can be maddening difficult to overcome this expectation.
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That’s one of the reasons that pros announce where they’re going and what’s going to happen.... WHEN the engine(s) quit... on every departure.

The assumption has to be that every takeoff can and will end in mechanical failure.

Just like every glider tow is going to end in a low level rope break.
 
PaulS said:
This crash involved pitching the nose up when it should have been pitched down. A quick glance at the airspeed indicator would have given the information needed in this circumstance. The AOA is a bonus.
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This crash happened when he pitched the nose up on the lake. LOL. The rest was just deciding what he was going to hit.
 
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