I have read the RCP (RCSA11-23-2)and the current rule a dozen times looking for an answer to a question that was discussed at the Fayetteville contest.

The question was concerning the sportsman maneuver 4 (2010 know) snap followed by a 1/2 Cuban 8.

The example is the pilot completes the snap and the nose is up in pitch by 10 degrees. The rule states that the pilot should correct pitch roll, and yaw no penalty applied. However, if the pilot did correct pitch and resumed a level and straight line of flight he would get a downgrade of at least 2 points for drawing a line between the snap and the ½ Cuban 8. If the pilot was to keep the 10 degree pitch and just continue straight into the ½ Cuban 8, should he get a downgrade for not correcting pitch after the snap?

Section G of the RCSA11-23-2 is clear if a straight line is flown before and after a snap, where I see a grey area is when a loop is to be flown after a snap. Let’s say he is up in pitch by 40 degrees, then it is clear he could not start a loop (1/2 cuban) from 40 degrees without some kind of a downgrade, if nothing else he would have a radius change or a flat spot in the loop element.

Jerry,

I would judge this as follows

I would expect to see an immediate pull into the 5/8th loop as soon as those corrections are complete. Any discernible line following the return to level flight after the snap would be deducted starting at 2 points.

Bill, if the snap is done correctly, the plane may be offset one way or the other from straight and level flight AFTER the snap then immediately pull the half cuban. One has to be careful to keep ones wings level or you will most definitely be off by at least 10 degrees and come out crooked and really mess up your cuban.!

Bobby

Posted By Bobby Folsom on 20 Apr 2010 22:36
Bill, if the snap is done correctly, the plane may be offset one way or the other from straight and level flight AFTER the snap then immediately pull the half cuban. One has to be careful to keep ones wings level or you will most definitely be off by at least 10 degrees and come out crooked and really mess up your cuban.!

Bobby

I agree Bobby,
A properly done snap will show the plane to be off it's original line in some respect. Let's say a positive snap, I would expect the plane to come out a touch higher(pitch break)and to the side in the same direction the rotation occurred. Some planes will show very little change but it should be there. Even the rule book gives this same example to help judge a snap

To me the best way to go from a judging standpoint is to see the pilot correct the exit of the snap to return to level flight and as soon as that is established I will expect to see an immediate pull into the 5/8th loop. Any discernible line will earn deductions. Any over-corrections will also earn more deductions. In any case, the decision to start the loop must be a quick one so the pilot needs to recognize quickly that the plane has returned to level flight.

As a pilot, if I come out of the snap wings level but 10 degrees nose up, I'll go right into the loop as the 1 point for the nose being high and not correcting it is much better than the possible two or more points I'll take if I screw up and draw a line (I've been known to do that very thing), not to mention over-correcting and getting those points off as well.

If I have been doing it wrong all this time, I would certainly like to know. I strive hard to be a really good judge.

Are you judging the NATS this year?

Aways remember that a snap is a stalled condition and the aircraft has to regain flying speed. At this point the aircraft's attitude should not be relevant for deductions as we the judge should be focused on the CG track and if an aircraft that has completed a positive snap from upright and is to immediately execute a Half Cuban or half loop the attitude of the aircraft should not create deductions.

Posted By Kent Porter on 21 Apr 2010 0:12
Aways remember that a snap is a stalled condition and the aircraft has to regain flying speed. At this point the aircraft's attitude should not be relevant for deductions as we the judge should be focused on the CG track and if an aircraft that has completed a positive snap from upright and is to immediately execute a Half Cuban or half loop the attitude of the aircraft should not create deductions.

Much better way to explain it, thanks Kent

It is my opinion that the aircrafts inboard wing is stalled during the snap and once the controls are released, it immediately starts flying again. Therefore, if not immediately corrected, the plane will not track in the correct direction. With that said, I agree 100% with you Kent, that track and not attitude is the judging criteria.

It is my understanding that the plane being off center after the snap should be used as a clue only. You should see pitch break and auto-rotation. If you saw that, and after the fact realize there was no displacement, you should still score the snap.

Kevin

After reading Kent’s comments a light bulb went off in my head. Bottom line is only judge the over/under rotation of the snap and the path of the aircraft’s C.G.

Here is a flow chart as I interpret the rule:

1 Did the pilot snap?
No- zero the maneuver
Yes- deduct for over or under rotation only
2 Is the C.G. of the aircraft traveling at the pre determined flight path? (Can be a line or arc as described by the Aresti)
Yes- No deductions
No- deduct .5 points per 5 degrees
The nose pitch alone is not the determining factor, only the flight path of the C.G.

Yep you got it

Quote from post #1: The example is the pilot completes the snap and the nose is up in pitch by 10 degrees. The rule states that the pilot should correct pitch roll, and yaw no penalty applied.



There is penalty for correction of roll at the completion of a snap.

Hope this helps, Dan Baker

Dan- that is the key to the grey area in the rule. In the example I see it okay for the nose to be up in pitch and then go into the loop element. The path of the CG would then be on the pre described path. If the pilot was to correct the pitch back to level flight, then he would most certainly draw a line between the snap and the loop element, therefore he would be downgraded by at least 2 points.

I watched pilot after pilot do this maneuver last weekend and 10 out of 10 ended up with the nose up in pitch. Some were very little, and some were extreme. The ones that nailed the snap in rotation and then went immediately into the loop element looked the most natural and appealing. I did not see any pilot bring the nose back down to level and then pull into the loop. I can see this in my head as looking like a bobble in the air and not a smooth maneuver.

The rule says the pilot should correct pitch yaw and roll with no downgrades, however one could consider up 10 degrees in pitch is correct for the CG of the aircraft to maintain the pre described flight path. Just as if some yaw is required to maintain the flight path to correct for a cross wind. We should only judge the flight path of the CG.

Dan,

I do disagree with you on one count. If the pilot corrects for rotation, he cannot be dinged as he/she was already dinged for the over/under rotation. However the pilot can be dinged if the pilot over corrects.

As an example, if I come out of the snap with the wings not level, say 10 degrees, I just got dinged one point. If I correct to wings level and do not over correct I cannot be dinged again as that is double jeopardy but if I over correct then I can be dinged for that amount of over correction.

I just spent 5 ten minute flights doing snap after snap trying this out by purposely coming out not level and having to correct something and the only way to not have a track change was to come out wings level and nose very close to level which adding power right at the end of the snap worked wonders (gotta love needing some down thrust for the up lines), that way I did not have to worry about the wings and just start the loop

Interesting discussion. Seems to me though that a CORRECTLY executed full snap will end up wings level and pitch level, with plenty of airspeed for the 1/2 Cuban...UNLESS the pilot entered it with too little airspeed to begin with and/or buried it during the snap.

In my IAC days we learned very quickly NOT to make an obvious roll correction, as that removed ALL doubt from the judge's mind about a perceived error. You can "sneak" it out during the pull.

Easier said than done though

Earle

Posted By Earle Andrews on 22 Apr 2010 10:21
Interesting discussion. Seems to me though that a CORRECTLY executed full snap will end up wings level and pitch level, with plenty of airspeed for the 1/2 Cuban...UNLESS the pilot entered it with too little airspeed to begin with and/or buried it during the snap.

In my IAC days we learned very quickly NOT to make an obvious roll correction, as that removed ALL doubt from the judge's mind about a perceived error. You can "sneak" it out during the pull.

Easier said than done though

Earle

Earle... I agree with you..... It's "All in the technique"...
Ask Jason Noll..... he knows how to do it & so do many top pilots (Mark Leseburg, Kurt Koelling etc).... That is what separates the GREAT pilots!
Wayne

Hi Earle, thought you dropped of the face of the earth.

Yep you are right, don't do the roll correction if it is small enough and sneak it in during the pull with the idea that if the judge has to question himself if he actually saw the unlevel wings or not then he must give the pilot the benefit of the doubt. My problem is I have learned to do a lot of "sneaking" because I can't fly worth a damn anyway, let alone call a maneuver though I'm really good at forgetting to call a maneuver

Well....we just won't talk about that last thing

I'm gonna try and make a couple of contests this year, although my art business has been getting in the way of flying, practice, building, spending, etc. Trying to get my 35% Extra 330SC done, but looks like it won't fly until June the way my schedule looks.

Anyhoo...back to the topic. If the judge sees a nice clean snap and an IMMEDIATE nose pull into the 1/2 Cuban, I doubt that many can discern one wing slightly low or the nose slightly off heading....PROVIDED that no correction is apparent.

Now, if the wing or nose error is obvious that's another story, regardless of whether a correction is made. Someone else mentioned that making a correction would have to draw a bit of a line, which again confirms and compounds the error(s).

Still here in West (By God) Virginia!!
Earle

It is my understanding that pitch and yaw are not deducted departures on the snap. So the question is- do you correct them before the cuban or not. Say the plane comes out of the snap with the nose 10 degrees up, do I take the time to correct this to level before pulling for the cuban and risk drawing a line, or just go with the pull for the cuban?
James

James,

If it were me, and the wings were level, I'd use that 10 degrees up to start the cuban, at that angle it's going to be a pretty large 5/8th loop because if you pull any tighter you might just change the radius

That's exactly what I was thinking, but you beat me to it Bill.

Earle

Posted By Earle Andrews on 22 Apr 2010 20:53
That's exactly what I was thinking, but you beat me to it Bill.

Earle

Nanny Nanny boo boo

You actually hinted at that in one of your earlier posts It's all about learning to hide your mistakes.

I love being judged by an Unlimited pilot that has been flying Unlimited for a while and also has been judging for a while. They pretty much have a good idea where you might make mistakes and also where you are going to try to hide the corrections so they tend be more critical and see things that someone else might miss, at least in the few years I've been doing this, is just something I've noticed. Now before I get flamed on that, I know there are a lot of really good judges flying in the other classes, heck I'm one of them

Don't pat yourself on the back Bill, you know you suck!!!!
Just kidding
Doc

Posted By james taylor on 22 Apr 2010 21:23
Don't pat yourself on the back Bill, you know you suck!!!!
Just kidding
Doc

Just remember, payback is a biotch

Yea I can't fly worth a damn, that's why I judge a lot, I get tired of getting my butt whooped, especially by a 13 yr old

Dan,
I do disagree with you on one count. If the pilot corrects for rotation, he cannot be dinged as he/she was already dinged for the over/under rotation.

Bill: You are correct, I worded my response wrong. In post #1 pitch, roll, and yaw are all mentioned as free corrections to snap exits. Just to be clear, "yes" they are. However only pitch and yaw are also penality free in snap exit error as long as the plane returns to the same heading as the entry. I didn't want the body to think that and error in roll on a snap exit is treated like an error in pitch or yaw. Pitch and/or yaw can be corrected back with no deductions for the initial error. This is not true for roll.

From Mr. Taylor...... It is my understanding that pitch and yaw are not deducted departures on the snap. So the question is- do you correct them before the cuban or not. Say the plane comes out of the snap with the nose 10 degrees up, do I take the time to correct this to level before pulling for the cuban

James: Answer = Yes
Rule 8.9.3 paragraph III , page 26 of AMA rule book, this web-site, homepage. (pasted below)


But for all aircraft types, the criteria for stopping the snap roll is
the same: the attitude before starting the snap roll and in the instant of stopping it must be identical

James: Answer = Yes
Rule 8.9.3 paragraph III , page 26 of AMA rule book, this web-site, homepage. (pasted below)


But for all aircraft types, the criteria for stopping the snap roll is
the same: the attitude before starting the snap roll and in the instant of stopping it must be identical

Okay, I think that I see the source of my confusion here. "the attitude.....must be identical" part had me messed up. In the case that I cited there would be a 1 point deduction for the pitch attitude change on the snap. Somehow I had it in my mind that you got a free pass on that.
James

Posted By Dan Baker on 30 Apr 2010 18:45
Dan,
I do disagree with you on one count. If the pilot corrects for rotation, he cannot be dinged as he/she was already dinged for the over/under rotation.

Bill: You are correct, I worded my response wrong. In post #1 pitch, roll, and yaw are all mentioned as free corrections to snap exits. Just to be clear, "yes" they are. However only pitch and yaw are also penality free in snap exit error as long as the plane returns to the same heading as the entry. I didn't want the body to think that and error in roll on a snap exit is treated like an error in pitch or yaw. Pitch and/or yaw can be corrected back with no deductions for the initial error. This is not true for roll.

Dan,
This has been bouncing around in my head for a couple of weeks now (obviously there is a lot of empty space in there!. The statement quoted above seems to me to be a contradiction to the rule that you quoted.

"James: Answer = Yes
Rule 8.9.3 paragraph III , page 26 of AMA rule book, this web-site, homepage. (pasted below)


But for all aircraft types, the criteria for stopping the snap roll is
the same: the attitude before starting the snap roll and in the instant of stopping it must be identical."

I have carefully read to rule several times and it seems very clear to me that finishing a snap with the nose pitched up by 10 degrees should be a deduction and be treated just like an error in rotation. I can't find any mention in the rule of a pass on this, only the requirement quoted above.

James

James: I agree with you on your statements above. I was going off my training in the judging schools where we learn that snaps are allowed to displace in yaw and pitch and be corrected at the snap exit (mind you, only yaw and pitch, this post is not about roll) without deduction as long as no discernible line is drawn at the very point in time of the snap exit

I will let our National Judging School Instructor firm up the rule with a post for us.

Thanks, Dan

Dan I agree wit you on this because we judge Track and roll !

Gentelman, First of all we need to know what is meant by the word attitued and the aplication of it in the rule book.

5.2: Attitude. The aircraft attitude is defined as the position of the aircraft in the sky, and is characterized by the variations it has on the yaw, pitch, and roll axis. In a ―no-wind‖ and normal speed condition, the aircraft‘s attitude (its heading) will generally point in the same direction as the flight path. In case of a cross wind, the aircraft attitude must vary (on the yaw axis) in order to maintain a constant and straight flight path, as required by the Scale Aerobatics rules (Fig. 2). Also, a reduction in speed will force the aircraft to change its pitch in order to maintain the correct flight path (Fig. 3). Depending the type of aircraft (low wing, high wing, etc.), the flight attitude might be different from one to another to maintain the correct flight path. Judges should disregard this difference in attitude and only concentrate on the flight path described by the aircraft.

Notice it refers to the attitued as HEADING. Because a snap displaces on the flight path in many directions, the flight path will not be in line before and after the snap. but the heading after the snap shall be identical to the heading before the snap. Or to say, The flight path after the snap should be parallel to the flight path before the snap. Now flight path is what we judge. A flight path is not judgeable in a stalled condition because it is not flying. But when flight is regained after a snap the flight path starts. Now if the heading is not correct, the flight path will be off.
A snap ends when the flight of the aircraft is regained, not when the roll ends. So as long as the tail moment is corrected (unloaded) before flight is regained, there will be no deduction. If corrections are made after flight is regained, then a deduction will apply. Also note that roll is a part of Attitude!! So roll or wings level shall be identical. This is where the confusion comes from. Rotation shall be precise.

5. Flight Path, Aircraft Attitude, and Wind Correction: Judges should evaluate any maneuver focusing primarily on the aircraft flight path, but at the same time, also downgrade for any variation of the aircraft attitude that is not directly related to maintaining a correct flight path.

Hope this helps,
Kurtis

Great answers guys! This a pretty complex subject but I think that we are on the same page in how to judge it. As for the original question, I would say no downgrade for the nose high pitch, do whatever you need with the plane to make the CG track transition to a constant radius for the partial loop. To correct the pitch or not would vary from plane to plane and depend on how much pitch up there was. The forward airspeed of the plane (and a lot of other factors) after the rotational portion of the snap will greatly affect the CG track in relation to the attitude so there can not be a single answer for all situations and planes. Also, the last part of the sentence that we have been quoting is very important: "...and must correspond o the geometry of the basic figure on which the snap roll is performed." Since the basic figure is a partial loop, the CG track should transition to a constant radius.
James

In the case where a plane finished the rotational portion with the nose extremely pitched up, say 45degrees, and didn't correct it, I would see it this way. With the power that we all have on our planes, they will regain flying speed very rapidly and the CG track would be a very tight radius. There would likely follow a radius change which would merit a 1 point deduction (no matter how dramatic the radius change is).

So let me dumb this down for me - the 4th Spotsman maneuver is a 1/2 Cuban, 1 Positive Snap on entry, 2x4 on the 45 degree downline

Calm wind

I am wings level right to left, I do the 1 positive snap and it comes out wings level 10 degrees nose up makeing no correction and I use the nose up of 10 degrees to establish my radius [probably pretty big]. I continue pulling 225 degees to a 45 down line for the 2x4 on center.

No Down Grade for not pushing down the 10 degrees before the 225 pull to the 45?

I don't know what everyone's answer would be, but my answer would be that it depends on the CG track of the plane. If the track is a nice arc as the plane transitions back to flying, and you don't change that radius through the 5/8 loop, then no downgrade from me since the exit of the snap conformed with the base figure.
James

That's the way I see it Gil. Just after the snap the plane is in a stall or near stall position, so the nose could be up 10 degrees to keep the CG traveling along the pre described flight path as described by the Aresti. If the pilot needed to correct the pitch or yaw to maintain the flight path, then he could do so without any downgrades.

Thanks to everyone who has taken the time to answer this post. It was my goal to get a better understanding of the correct way to judge this maneuver.

Posted By Gil R. Major on 24 May 2010 17:15
So let me dumb this down for me - the 4th Spotsman maneuver is a 1/2 Cuban, 1 Positive Snap on entry, 2x4 on the 45 degree downline

Calm wind

I am wings level right to left, I do the 1 positive snap and it comes out wings level 10 degrees nose up makeing no correction and I use the nose up of 10 degrees to establish my radius [probably pretty big]. I continue pulling 225 degees to a 45 down line for the 2x4 on center.

No Down Grade for not pushing down the 10 degrees before the 225 pull to the 45?

Gil, That would be a downgrade, Attitued (or heading) must be the same after the snap as was before the snap. Correct tail moment before the aircraft regains it's flight path and then pull the radius.

Interesting topic!! Now lets discuss a snap and a half. After this manuever, the nose can be yawed as much as 20 degrees depending on how "deep" the snap is. I have seen a couple of approaches by different pilots to try and finish with the same exit attitude. One is to cheat and aileron the last half roll. If caught, this should be an automatic 0. It is my opinion that the plane must stay in autorotation for the full manuever and then be immediately corrected on exit.

Kurtis,
Wouldn't that mean that you are downgrading based on attitude? See Rule 5, 5.1 and 5.2.
Rule 5 clearly states that "Judges should evaluate ANY maneuver focusing primarily on the aircraft flight path..."
James

If a snap is done correctly, the nose of the plane should auto rotate in a cone like fashion around a point on the horizon because during the entry of the snap the elevator should be pulled an instant before the other controls to get the wing into a high speed stall prior to rotation. Then to stop the rotation the elevator should have down applied just prior to the end of the snap which would get the wing flying again and out of it's stall condition, and the plane starts flying again on the line it entered the snap on. At least thats what happens in a full scale environment.
With my very limited experience with the models (and I mean limited), it is very hard to engage that "shot" of down elevator at the instant rotation stops to get the wing flying and in my case, it shows up as a bit of down the instant rotation stops which if I do it right (and mostly I don't......lol) get's me back on the line I started the snap on. Once heading is established within a very short period of time, it is time to start the pull for the 1/2 cuban w/ 2/4. IMO that correction has to be immediate and part of the snap??
So in my mind, I guess the real question is, are we required to exit a snap on the same line we started it? And if so, how does one do a perfect snap without loosing heading with these models?? I have seen some that perform a snap that looks more like a roll that don't loose heading, but IMO they should be downgraded for never doing the snap correctly in the first place?

Kurtis, I just reread what you wrote above and think it answered my question.


Terry

I like airplanes

Guys: Just to be perfectly clear (and blunt this time, forgive me). Please see my post 4th from the top, page 2.

If you do not correct the pitch up in the snap exit (ie, leave it 10 degrees up and just start the pull into the loop), there will be a 1 point deduction (1 per 10 degrees). If you have a pitch up of 30 degrees, it will be 3 points off if you do not correct it before you pull in to that loop.

Furthermore, there is no deduction if you correct the pitch up exit (down elevator command) as long as no discernible line is drawn, ie. flying forward before you start that loop.

Hope this helps, Dan.

Hope this helps,
Dan Baker.

For anyone interested...there is an article on "Snaps" on the IMAC website...
www.mini-iac.com/InfoCentral/tabid/...-Snap.aspx
Wayne

Posted By Dan Baker on 25 May 2010 21:30
Guys: Just to be perfectly clear (and blunt this time, forgive me). Please see my post 4th from the top, page 2.

If you do not correct the pitch up in the snap exit (ie, leave it 10 degrees up and just start the pull into the loop), there will be a 1 point deduction (1 per 10 degrees). If you have a pitch up of 30 degrees, it will be 3 points off if you do not correct it before you pull in to that loop.

Furthermore, there is no deduction if you correct the pitch up exit (down elevator command) as long as no discernible line is drawn, ie. flying forward before you start that loop.

Hope this helps, Dan.

Hope this helps,
Dan Baker.

Perfect, thanks Dan. But the judges (IMO) should consider that after the auto rotation has stopped and the pitch has been corrected there is a small amount of a line (time) that is needed to get the wings flying again.

Terry

Posted By Wayne Matthews on 25 May 2010 21:38
For anyone interested...there is an article on "Snaps" on the IMAC website...
<a rel="nofollow" href="http://www.mini-iac.com/InfoCentral/tabid/74/articleType/ArticleView/articleId/89/categoryId/38/Pilots-Judges-Corner-The-Snap.aspx">www.mini-iac.com/InfoCentral/tabid/...-Snap.aspx</a>
Wayne

Perfect, thanks Wayne.

That's the way I understood snaps and I see that IMAC has considered the pitch (which it should) when exiting the snap.

Terry

Posted By james taylor on 25 May 2010 11:28
Kurtis,
Wouldn't that mean that you are downgrading based on attitude? See Rule 5, 5.1 and 5.2.
Rule 5 clearly states that "Judges should evaluate ANY maneuver focusing primarily on the aircraft flight path..."
James

5. Flight Path, Aircraft Attitude, and Wind Correction: Judges should evaluate any maneuver focusing primarily on the aircraft flight path, but at the same time, also downgrade for any variation of the aircraft attitude that is not directly related to maintaining a correct flight path.

James, I guess you could say that I am, because the nose up attitued has nothing to do with maintaining a correct flight path. Because I can asure you that when the aircraft regains it's flight it will track that 10 degree line. Now I guess if you trottle back enough before the snap, the speed of the aircraft would require that 10 degree pitch to have a correct flight path but would be hard to transistion into a 1/2 loop radius. Rule 5. needs to be quoted in it's entirerity as in my post earlier.
The only figures that I know of that integrate snaps within the radius are depicted on the flimsy as such.
The snap criteria never changes, regardless of where it is located within a sequence. except for being intergrated within a radius.

James, I really thank you for your inquizzid mind and questions because it shows that you care. It makes all of us better!!!

Posted By Terry on 25 May 2010 21:53
Perfect, thanks Dan. But the judges (IMO) should consider that after the auto rotation has stopped and the pitch has been corrected there is a small amount of a line (time) that is needed to get the wings flying again.

Terry

Seems to me that if this is the case, the snap was done at way too low airspeed and/or buried during the snap. On my 50cc Extra as soon as I stop the snap the plane is instantly flying well above stall and can easily pull up into the 5/8 loop. Of course, I don't tend to slow down much for snaps anyway

Earle

Posted By Earle Andrews on 28 May 2010 11:57

Posted By Terry on 25 May 2010 21:53
Perfect, thanks Dan. But the judges (IMO) should consider that after the auto rotation has stopped and the pitch has been corrected there is a small amount of a line (time) that is needed to get the wings flying again.

Terry

Seems to me that if this is the case, the snap was done at way too low airspeed and/or buried during the snap. On my 50cc Extra as soon as I stop the snap the plane is instantly flying well above stall and can easily pull up into the 5/8 loop. Of course, I don't tend to slow down much for snaps anyway

Earle

Mr. Andrews is correct, watch the upper class guys snap, they enter at say 40 mph and exit at 40mph.

Wow...I'm showing this to my wife, she say's I'm always wrong.

AND....last time i was referred to as "Mr." was for a traffic violation.

Earle