A snap roll is an autorotation with rudder input and generally higher power or higher speed.
One wing is stalled in a snap roll, both wings are stalled in a spin. - Do you agree at all with this last statement?
Snap roll VS Spin
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Re: Snap roll VS Spin
Doing a snaproll with the C152 is like a spin but in the horizontal plan... Speed is 80kt and below (lateral load factor limitation), add power to 2100rpm firmly aft stick and left rudder...
The difference is that you're not idle. Either a spin or a snaproll, one wing has a highter angle of attack so this wing will stall first. To recover from a snaproll or a spin, you have to apply opposite rudder a release back pressure on stick.
Hope this help you and if any pilot want to confirm my text or correct it
Raf
The difference is that you're not idle. Either a spin or a snaproll, one wing has a highter angle of attack so this wing will stall first. To recover from a snaproll or a spin, you have to apply opposite rudder a release back pressure on stick.
Hope this help you and if any pilot want to confirm my text or correct it
Raf
Re: Snap roll VS Spin
This statement sounds like someone is trying to separate a snap roll from a spin, when really they are inseparable. My understanding of a snap is that it's a accelerated spin in the horizontal (or on the upline, downline, whatever). I start a snap by stalling the wings, while almost simultaneously adding full rudder in the direction I want to snap. Immediately unload the stick to keep the snap from being buried. Fun ensues.Rich_Pa wrote:One wing is stalled in a snap roll, both wings are stalled in a spin. - Do you agree at all with this last statement?
Re: Snap roll VS Spin
Congratulations, you are getting into one of the most complex and often misunderstood aerodynamic flight configurations. I need to visit this side more often. Surprise some of the permanent members didn't jump on this topic already.
In snap roll you can be as fast as 160kts and +/-8to10G or more in unlimited monoplane.
You can spin an aircraft at full power. In fact that trick was used by the best unlimited pilots during the "short free style bonus era".
Since you are at Vso / 1G condition in a spin, your trajectory will be ballistic towards the ground.
In the snap roll your trajectory can be in any direction, including vertical up line.
You can also snap at idle power, providing you have enough speed. You will sometimes see snaps on the down lines at very low power settings in competition.
-one wing stalled, and the other one not,
-one wing fully stalled and the other one partially stalled,
-or both wings stalled, but one deeper then the other,
-or bigger part of one wing versus the other stalled to achieve auto rotation in an GE types with a wash out (twist) in their wings.
Most GE aircraft will have wash out to make stall more docile and maintain some aileron effectiveness in the stall for those ham fisted pilots - C152 Aerobat is classic example. In comparison, fully blown aerobatic types will have zero twist, zero incidents, and thinner airfoil at the tips. That causes the tips stall before the wing root for those extra crispy snap rolls.
To understand this better it's important to remember, that even fully stalled wing will create some lift. A fully stalled wing at higher angle of attack will create less lift and more drag - see Lift/AoA/Drag graph.
All very different from the stick and rudder perspective.
Hope that helps.
Not exactly. Power has nothing to do with it. Speed and the resulting G-load required to archive the critical angle of attach is the difference. In spin you are at Vso or slightly above and 1G (positive in right side up spin and -1G in inverted spin).A snap roll is an autorotation with rudder input and generally higher power or higher speed.
In snap roll you can be as fast as 160kts and +/-8to10G or more in unlimited monoplane.
You can spin an aircraft at full power. In fact that trick was used by the best unlimited pilots during the "short free style bonus era".
Since you are at Vso / 1G condition in a spin, your trajectory will be ballistic towards the ground.
In the snap roll your trajectory can be in any direction, including vertical up line.
You can also snap at idle power, providing you have enough speed. You will sometimes see snaps on the down lines at very low power settings in competition.
No. To achieve auto-rotation in either spin or snap, you will need lift and drag asymmetry between the wings, nothing else. That can be achieved with:One wing is stalled in a snap roll, both wings are stalled in a spin. - Do you agree at all with this last statement?
-one wing stalled, and the other one not,
-one wing fully stalled and the other one partially stalled,
-or both wings stalled, but one deeper then the other,
-or bigger part of one wing versus the other stalled to achieve auto rotation in an GE types with a wash out (twist) in their wings.
Most GE aircraft will have wash out to make stall more docile and maintain some aileron effectiveness in the stall for those ham fisted pilots - C152 Aerobat is classic example. In comparison, fully blown aerobatic types will have zero twist, zero incidents, and thinner airfoil at the tips. That causes the tips stall before the wing root for those extra crispy snap rolls.
To understand this better it's important to remember, that even fully stalled wing will create some lift. A fully stalled wing at higher angle of attack will create less lift and more drag - see Lift/AoA/Drag graph.
Again, not exactly. Only true in the spin. In a proper competition snap, the stick will be forward already, in most types all the way to the stop, in order to accelerate the auto-rotation. Therefore you can not "release the back pressure". You stop the snap with the opposite rudder. Unless it's only a half snap, but that's the whole new can of worms...To recover from a snaproll or a spin, you have to apply opposite rudder a release back pressure on stick.
Maybe so aerodynamically, but from a competition pilot perspective, spins are very different from snaps, full snaps are very different from half snaps, halfs are different then then 3/4, and 11/4, and 11/2, and so on. And that's only horizontal positive snaps. Then we have all of them on vertical and 45 up and down lines. And of course we have all of them at negative angle of attach - outside snaps. And the ugliest of them all - positive snaps from negative lines, and outside snaps from the positive lines.This statement sounds like someone is trying to separate a snap roll from a spin, when really they are inseparable.
All very different from the stick and rudder perspective.
Hope that helps.
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Re: Snap roll VS Spin
I might point out that with one type of aircraft,
you can do many different spins. They can be
upright, or inverted. They can be accelerated
(upright or inverted). They can be flat (upright
or inverted).
Different types of aircraft spin notoriously
differently. What works in one type will NOT
work in another.
Trying to simplify all of the above into a binary
yes/no answer is a bit ridiculous. Life is not a
TC written exam.
you can do many different spins. They can be
upright, or inverted. They can be accelerated
(upright or inverted). They can be flat (upright
or inverted).
Different types of aircraft spin notoriously
differently. What works in one type will NOT
work in another.
Trying to simplify all of the above into a binary
yes/no answer is a bit ridiculous. Life is not a
TC written exam.
