Spin entry? and Snaps...
 

I have read a lot but Im curious about what you all have to say about good spin entry and execution and how you IMAC guys like to see a snap.

Spin- Basically I let the plane slow to stall speed feeding in a little elevator as it slows and then let it drop whichever wing it wants as it stalls. As I watch the plane and see which wing drops and as the nose drops I feed in full rudder and aileron and up elevator. To exit I let off the controls bump the ailerons to stop the spin and fly out... Is this correct? I know what judges are looking for in a spin in pattern but Im learning as I go in IMAC. I know you dont want the wing that doesnt drop to "come over the top" as you enter the spin (not really a spin) .

Also on a snap how much break are you looking for? I know the difference between telegraphing and truly breaking the nose without gaining altitude, but How axial do the judges like the snaps? I can get massive snaps with a nice timely break using full deflection but Im not sure how "big" of a snap you are looking for. In pattern you will get a zero if the snaps dont show break and the nose and tail conically rotating but guys get away with what looks more like a roll than a snap all the time.

Is it better to go easy on the elevator and rudder and make a more axial snap or go ahead with full deflection and truly snap the plane which is going to slow it way down and really change your line quite a bit from entry to exit?


Feel free to hash this out, I learn a lot from listening to other people debate these things.

RE: Spin entry? and Snaps...
 

This should be a long thread! LOL. Great questions.

Craig

RE: Spin entry? and Snaps...
 

A good sized group of us here in the Southwest just attended the first Advanced Judging Seminar put on by the IMAC leadership. All our "Thanks" to Anna Wood for putting this great seminar together. It was a great chance for a group of experienced judges and pilots to get together with some experts and the judging guide and get things straight. Several of those who attended are active here on RCU (Aresti2004, quist, badarkstar, jelaird).

Snaps and spins were discussed for about an hour. The IMAC judging guide is pretty specific on what the required elements are. There are many judges that have their own criteria and are judging you incorrectly.

Here's the jist of the spin. It MUST stall. A stall was defined as simultaneous movement in roll, pitch, and yaw. Beyond that, it's just a discussion on downgrades and zeroes.

Many judges would zero a spin if the nose didn't drop first to prove that you stalled. They are wrong. The perfect entry has the nose dropping, one wing dropping, and the plane yawing all at the same time. You are correct that a snap entry is a zero. That's pretty obvious because one wing raises up over the top instead of one wing dropping as the nose drops. If the rotation is a spiral instead of a stalled autorotation, that's also a zero. The downgrades are all found in the judging guide.

There was a long discussion on snaps. The actual criteria requires the nose of the airplane to displace from the FLIGHT PATH. There is no criteria on how much it must displace. It is also acceptable for the nose to displace from the flight path at the same time that the autorotation occurs. I've seen lots of zeroes from judges that want to see the nose break first. Again, they're wrong. Just as with the spin there are specific things that are downgraded on this manuever, along with the general downgrades.

The bottom line is, read the judging guide. As Aresti2004 has pointed out many times, it and other great references are available on the IMAC website.

Learn the criteria correctly, and encourage all pilots and especially judges to learn them. Too many judges are just doing what they think is right, or what someone else told them was right.

Best of luck to everyone this contest season!!

Dean Bird
Sun Valley Fliers
Phoenix, AZ

RE: Spin entry? and Snaps...
 

Dean thanks for the info and I look forward to a lot more from everyone else it will be useful, most of it just gave me peace of mind about what Im already doing thank goodness.

My problem is that although there are tons of pattern flyers near me and several I fly with daily, there isnt another practicing IMAC pilot within 80 miles that I know of. I have read the judging guide and studied the tips on the IMAC, practiced on my sim and burn a lot of gas at the field,,, but other than the video that was posted here the other day I havent ever even seen an IMAC sequence flown so I am going to have to get all I can get here before I think about going to my 1st competition... As you can tell Im in the sportsman sequence, I flew the basic for a couple of weeks but there wasnt much to be gained in it for me so Im skipping for good reason. I can fly the maneuvers in sportsman cleanly and with relative geometric precision I just need clarification on centering, some basic questions about the meneuvers I mentioned before and stuff like that to clean things up.

Another question would be roll rate judging. For instance on the roll before the immelmann turn, do the judges score better for a slower more controlled roll or do most guys just push the stick over and roll it. Also the rolls in up and down lines. Is there an advantage to making them slower as well provided they are centered in the line? In pattern and IMAC it says that roll rate is not a judging criteria BUT BUT, guys who roll more slowly and with more control get better scores. This is somewhat subjective, but none the less true, does this apply in IMAC as well? I can roll slow I just want to be sure I practice doing what the judges prefer to see.


Where Im coming from. I flew pattern for a while but I have limited funds for multiple planes and I like to fly sequences, pretty much all you can do with a pattern plane is fly pattern... I chose scale aerobatic planes and sold my pattern plane becuase I can fly sequence and 3D with the same plane. So dont chastise me for going to sportsman where I can challenge myself, basic wasnt fun for me and win or lose having fun is why Im into RC planes.


Mike

RE: Spin entry? and Snaps...
 

Mike,

Definitely fly in whatever class is going to be fun for you. That's what is supposed to be about. I have to be reminded of that a couple times a year when I get way too serious and way too competitive.

I'm glad to see you've read the judging guide. That IS the place to start. But with that said, it sounds like your pattern experience has already made you aware that some judges like certain things and will reward it. That is WRONG. Every manuever starts at a 10, and the deductions that you observe are subracted from that. Because someone likes to see slow rolls, they shouldn't be adding points back on. There is no criteria anywhere that allows a judge to add points back on after the deductions are taken.

You mentioned "centering" in general terms. Because of the zoneless box, there aren't any manuevers that have "centering" of the manuever as part of the criteria. The "centering" of roll elements on the internal lines in a maneuver are definitely a criteria. It's easy to know. It just has to centered. The only exception I remember is the spin/roll combination in a manuever. Obviously those won't be centered on the downline and it isn't a criteria for that manuever.

Roll rate is purely pilot preference and ability. You do what you can, and what will score best for you. If rolling slow on a down line causes your roll element to be off center, you lost points. If rolling slow on a horizontal line creates a lot of flight path deviations, you're losing points. You can roll as fast as you want. The challenge with rolling fast is controlling the stopping point consistently. If you keep missing your exit point and losing points, you're probably rolling too fast.

Even with all that, you sometimes have to fly what will get the best score with the majority of judges. By the book, the perfect spin has "simultaneous movement in roll, pitch, and yaw". There are many judges that would zero the perfect spin because they didn't see the nose drop first to prove you stalled. To play the percentages, I always let the nose drop some before initiating the spin. A slightly lower score from a judge that knows the criteria, but I stay away from the zeroes from the misinformed judges. There is also no criteria that says the airplane must stop to initiate a "simultaneous movement in roll, pitch, and yaw". There are judges that will give you a zero if the plane is still moving forward when it stalls. This is also misinformed. There is no criteria that says the plane must stop before it stalls. Planes can and do stall while still moving.

As with spins, in snaps it's OK to have the nose displacing from the FLIGHT PATH at the same time as the autorotation. But some judges would zero that. They expect to see the nose displace first, then the autorotation ensue. They are wrong, but I fly it that way to stay away from the zeroes.

You seem to be well aware of the criteria. I'm sure you'll do great!! Have fun at your first contest!!!

Take care,

Dean Bird
Sun Valley Fliers
Phoenix, AZ

RE: Spin entry? and Snaps...
 

I have a DPM540T Which doesn't have a well defined Stall at all, how do you convince the judges That the plane is stalled as you enter the spin.

RE: Spin entry? and Snaps...
 

Oh man Im overcompetitive too. Thats part of why I intentionally fly in a class where I probably cant win. If theres a good chance of winning I tend to get almost ravenous about judges scoring and my own performance. If fly fly a class ahead I know that I have no chance of winning so I can concentrate more on having fun while improving my skills. Pretty sad eh?

Anyways, I went out today and worked on my snaps since we had discussed this earlier. I snapped so many times I actually snapped the head right off of my pilot, lol. Thats a true story Im not making it up.

I found that you can snap these scale aerobatic planes by initaiting the snap with up elevator and still keep the plane on track, you can do it without letting the plane get off track by following the noses break in pitch. You just have to get into the other controls a split second after you bump the elevator and then I found I need to get out of the rudder early to let the forward momentum help keep it on track at the exit. My Edge 540T snaps a lot more violenty and with much larger nose and tail cones than my Propechy (pattern plane) did. Plus its a lot harder to stop on the mark, and stay on the proper heading. I can see its going to take a lot of practice to nail it consistantly but I will have a lot of fun trying.

I think Im already doing what you described as far as the spins. Im always very careful to let a wing drop and then just follow that wing into the spin, the key is to be patient and let the wing truly stall and not end up letting the trailing wing come over the top at the beginning of the spin. Practice practice practice....

I couldnt believe I killed my poor pilot today.. I think Im going to replace him with one of these scary pilots that look like something out of deliverance.[8D]

RE: Spin entry? and Snaps...
 

One issue that must be dealt with in spin entry is that you sometimes,
depending on the following maneuvers in the sequence, have to
spin in a particular dirction and so cannot follow the dropped wing
that the plane wants to give you. You have to anticipate this and make sure
it goes where you want it to.
Bruce

RE: Spin entry? and Snaps...
 

I thought you had to have a true stall. If the nose does not drop before it drops a wing, which does happen, and the plane goes left and you force it right thats not really a true stall into a spin, right or wrong?. You are forcing it to spin and thats a zero,,, am I correct? I thought the whole purpose of the of the manuever was to demonstrate a true stall condition followed by a spin. Sure if the nose drops 1st then you can perhaps react quickly and subltly force a wing down in the direction you want it to go but you are effectively cheating when you do that huh?

RE: Spin entry? and Snaps...
 

BigNed,

Can you point me to this video?

RE: Spin entry? and Snaps...
 

[link=http://www.psk560.com/05sportspsk.wmv]Sportsman Video[/link]

Thats a link to the site, actaully it was posted in another thread called 2005 sportsman sequence.

Mike;)

RE: Spin entry? and Snaps...
 

Thanks, I did find it 30 seconds after I asked but was unable to get back to tell you that. [:o].

RE: Spin entry? and Snaps...
 

For IMAC, a proper spin entry involves the simultaneous dropping of the nose and wing when the plane reaches stall speed. If the nose only drops first, then that is a deduction. I believe pattern is the opposite.

Because there are spins which end cross-box, you have to be able to get the plane to spin in the direction you want. Otherwise, you could be going in a direction you didn't want.

You do hear Edge pilots talk about spin entries, because the straight leading edge of the wing provides the Edge with a significantly lower stall speed than other designs. So Edges tend to sit up there waiting for something to happen. This is really noticeable when there is a good head wind. The plane will stop in the air, but is not stalled. It will sit up there are long as you want to hold the elevator. Sometimes, they will start to mush down, almost like a harrier maneuver. If this happens, you waited too long to initiate the spin. In calm air, remember that stall speed is a speed at which the wing does not provide lift, and this will happen before the ground speed reaches zero.

A stalled condition is not the same as zero ground speed. We are not looking for a plane to stop in the sky in relation to the ground, but for an actual stall. When you see a true stall and the nose drops, you can't mistake the stall, even if the plane is still moving forward. One of the reasons spins are always performed into the wind is that downwind spins don't always slow down before the stall and the entry looks awful, even though it is fine. Most judges won't give as good a score to a downwind spin as to an upwind spin, even if they are otherwise equal. (Not saying this is right, but it is a fact. Downwind spins look ugly.)

I fly an Edge and when the plane gets to stall speed, I simply feed in rudder and the nose and wing will drop just like any other plane, in the direction of the rudder input. You will get autorotation.


Barry

RE: Spin entry? and Snaps...
 

This video is a good learning tool.

The spin was a zero. There was no stall or autorotation. The nose was pointed down and was followed by an aileron roll. There are videos of both the basic and sportsman sequences. Each have a spin. Both spin entries were the same, and both would get a zero.


Barry

RE: Spin entry? and Snaps...
 

hmm, thats different than what I read earlier in this thread I think.

I have an Edge 540T and sometimes the nose will not drop it just sits there and sits there and eventually will drop a wing. Sometimes it will drop one wing and then quickly the other wing drops immediately. I know Im playing dumb here,,, what is going on is you are forcing the plane go into a stall and spin but its not really a true stall and autorotation. Thats the only way you are going to get it to go the direction you want everytime.

OK so I got it, I know what to do to make it "look" right even though if the judge could score your stick inputs he would zero you for forcing the wing you want to drop, forcing autorotation in the direction you want it to go. :) I can do that...

RE: Spin entry? and Snaps...
 

BigNed:
You're confused. Making your plane enter a spin in the direction you want it to go is not a downgrade. Letting the plane decide which wing to drop by holding the elevator and waiting and waiting is not the "perfect spin entry". There are simply no rules that say a spin has to be fully developed with autorotation on elevator input alone.

RE: Spin entry? and Snaps...
 

I understand that Diablo.. Im just trying to get to what you guys who are doing the judging view as spin entries that are considered acceptable and will not result in a downgrade... I see that the quick reference says "no wing drop in direction of spin as nose falls". That sure sounds like the nose must drop for maximum score.

Im telling ya on a windy day my 30% Lanier Edge WILL NOT stall the nose before it drops a wing,, I guess you are just screwed if that happens,,, or I could let in a little down elevator so the nose will drop.

RE: Spin entry? and Snaps...
 

What "quick reference" are you talking about BigNed?

Here is the rule from the judging guide:

For upright spins entered from upright flight -
When the aircraft stalls, the nose will fall and at the same time the wing tip will drop in the direction of the spin. Failure to achieve this should be considered a "forced entry" and downgraded 1 pt per 10 degree deviation.

No down elevator needed. Give it up elevator, don't climb, then you decide when to add rudder and aileron in the correct direction so that wing drops "at the same time as the nose". It's a timing maneuver that can be influenced by the wind, your plane, and your idle speed.

RE: Spin entry? and Snaps...
 

Its on the IMAC website. Its a judging quick reference guide right below the sequence download section. .

I hear ya on what the rule says but with a headwind the nose on my Edge wont drop at a dead stop. IT will drop a wing but the nose never sinks, the nose pretty much slides off as it follows the wingtip down into the spin. My confusion was from what I had read in a post earlier, I thought I understood that in truth the nose does not have to drop as long as a wing drops to initiate the spin. Im not a rookie, I know what I see. Im just new to IMAC. Maybe a higher elevator rate will do it. Im entering the spin on my low elevator rate which max's out at 12 degrees.


I'll try switching to a higher rate and see if it will drop the nose since the rules clearly state that the nose must drop. I will figure it out.

RE: Spin entry? and Snaps...
 

you guys are reinventing the wheel here.

you can (and will) be downgraded if you yaw the airplane sufficiently to lead the direction of the spin if the nose loses track. so, yes, you can be downgraded for leading the direction of a spin. however, in a crosswind, you will have to yaw the aircraft at the entry. the trick is to keep the yaw consistent with the track, if not the departure is downgraded one for ten. in many years of CDing/judging/flying/rules and/or sequence committees i have never heard anyone remark that the spin entries for pattern and imac are different, nor have i seen so called imac pilots scoring higher in spins than the guys that come over from pattern - which, incidentally, includes almost all the TOC pilots - several of whom I have judged, and most of whom I have watched. you guys want to tangle yourself up, discuss the entry/scoring of a cross-over spin.

if the spin entry is scored, an autororation must follow. if not, zero.

A forced entry is not downgraded, it is zeroed. the difficulty is catching it, which is not that easy, and has been the source of more than a few disputes. A spin has three components, and any one of them can cause a zero for the entire figure, they are not downgraded individually. if the plane snaps the entry, it is a zero, if there is no discernible stall it is a zero, if there is not autorotation, or if the autorotation exceeds or is less than the desired exit it is a zero.

last...in the lower classes a spin is a low K figure - contests are not going to be won or lost on spins. it makes for interesting conversation, but i would spend more energy understanding the judging of any figure that goes vertical.

aresti 2004 (bill) wrote the judging summary, i am sure that if you have some questions about content he will respond.

PK

RE: Spin entry? and Snaps...
 

I understand line segments, rolls centered on lines, equal radii good geometry, wind correction and all that. The only thing other than what we are discussing im unclear on is centering and from what I read and watch centering is a non issue.

Ok. On my edge the wing drops and the nose follows, it just doesnt stall nose 1st. I'll work on getting the nose to drop 1st. Also how are these guys getting away with leading the direction of a spin to get the desired exit if leading the direction of the spin is a zero or at least a severe downgrade? There is a big difference between yawing the plane to maintain track and yawing the plane to initiate the desired rotation of a spin. I always understood that a stall was something the plane did, not something the pilot did. The pilot just follows the planes natural motion based on which wing goes 1st, that is determined by wind and lateral balance eh?



Getting off into the weeds here..
One of the big things I learned with pattern is you can yaw the plane all you need to as long as the plane maintains the correct track. IE a vertical upline with a crosswind. You can point the plane into the crosswind on the upline or downline and still travel perfectly vertically. Even though the planes centerline is slightly perpendicular to the track, the track of the CG is still vertical and not being pushed in or out by the wind. Or as mentioned yawing the plane to maintain a track parallel to the flight line when traveling straight down the box. Or I would think as you said the plane would enter the stall yawed nose into the wind to maintain track and then let the chips fall. This is not a downgrade in pattern and actually demonstrates expectional control, Im sure the same holds true in IMAC.

Thanks for the continued discussion this is very interesting and educational for me.

RE: Spin entry? and Snaps...
 

OK, I checked the pattern rules, and they are the same as the scale aerobatic rules as to the stall in a spin. Both require the nose and the wing to drop simultaneously.

If you yaw the plane to initiate autorotation, you will get dinged. I described my method, which involves inputing rudder just as the plane stalls. There is no "yaw" into one direction or another doing it this way, all you get is the autorotation. If you get real yaw, you input the rudder too soon.

Edges can be a bear to spin because of their low stall speed. But there are some cg issues you can play with which will help, too. If you are tail heavy, it might be really hard to get the nose to drop. If you are set up for 3D, that might be part of your problem. I fly mine a bit tail heavy, but not much. Just enough so the snaps are crisp. Each maneuver requires a little different set up. So what you have to do is compromise to get the best overall set up. But I have put Edges into spins and have seen other pilots do it as well. It can be done.

You can yaw your plane in scale aerobatics all you want, too, as long as it is for wind correction. Aresti 2005 once flew in a 90 degree cross wind and did a beautiful job of yawing the plane to keep a straight track. He then reached stall, and autorotation. Only the judge didn't know the rule and dinged him for yawing so far from a straight attitude. For spins, you can yaw for wind correction, but not to ensure a particular spin entry.


Barry

RE: Spin entry? and Snaps...
 

Yup pattern rules say the nose must drop. But usually you dont see a downgrade as long as the nose OR a wing drops clearly indicating a stalled condition. Big hits I saw in pattern (advanced, which I judged) were for snapping over into a spin or visibly forcing a wing to drop. As long as the plane clearly indicated a stall by dropping the nose or a wing you didnt get downgraded.

RE: Spin entry? and Snaps...
 

Say PaulBK:
I posted the official AMA scale aerobatics rules for spin entry above.
A forced entry is defined by them.
A forced entry is scored, and downgraded 1 pt per degree of deviation.

Are you saying the rules are incorrect as written?

RE: Spin entry? and Snaps...
 

Not quite right. Let me clarify this a bit. What Barry is really trying to say here is that if you yaw the plane prior to the start of the autorotation of the spin for anything other than wind correction, that will result in a downgrade. In fact it is the yaw combined with the stall that results in the autorotation of a spin. Not all stalls result in a spin. But all spins require a stall in combination with a yaw component.

A prefect spin will be achieved when the judge's see the plane approach a stall with no deviation in altitude or track (yaw for wind correction is allowed), then the plane stalls and the wing drops in the direction of the spin. This will result in the nose simultaneously yawing in the direction of the spin as the wing falls away from level. In fact this is a sort of chicken/egg thing. It is very hard for the wing to drop without a yaw compnent and vice versa. The plane will then autorotate for the prescribed number of rotations (up to 2 maximum), stop at the correct number of dergees of rotation. A straight vertical downline (wind corrected if necessary) is then established and the plane exits with a smooth 1/4 loop to level with the wings level and no deviations in track (roll, yaw, pitch).

If the plane does not stall, it is a zero. This is usually seen by the "sneak" entry where the pilot pushes the nose over without the plane stalling.

If the plane stalls and the nose and wing do not immediately fall in the direction of the spin, that is a downgrade of 1 point per 10 degrees of deviation. While the rules call this a forced entry what most judges mean by that term is an non-stalled "sneak" entry.

If the plane snaps into the spin, usually evidenced by the outside wing (the one opposite the direction of the spin) rising up or the nose also rising up, that is a zero as well.

Hope this helps.

Bill