Incessant Problems -- Cloverleaf

[Tim Wescott]

Just got reminded of this because of James Holford's posting about his first cloverleaf, but this didn't belong there.  So, with apologies to Brett for stealing his titling format, I'm going to launch into this one.

The cloverleaf offers opportunities for just about every error that Brett has covered so far, with the exception of the ones dealing with corners.  Here's the most common screwups I see as a judge, and in my own flying.  Have the rulebook open when you look at these; it is, always, your reference.

Note that everything that's been discussed about loops applies to the actual loop-ish parts of cloverleafs, so I'm not going to repeat that here.  Note also that I'm not as good as Brett at actually giving reasons for things, although I'll try.

The screwups that I see are:

• Straight lines too short, the cloverleaf is "scrambled" with overlapping loops.  Sometimes it's just the horizontal straights, sometimes it's the whole maneuver.
• Horizontal lines slope up
• loops too small or misshapen

[Tim Wescott]

"Scrambled" cloverleaf.  The picture is only exaggerated in the sense that when someone gets the horizontals that bad, they're usually getting the verticals off, too.

This comes about because, first, the pilot is not visualizing the maneuver correctly, or is not used to how the cloverleaf should feel as its being flown, second, because of plain old fear, and "third" (and fourth, and fifth, etc.), for all the reasons that we screw up loops.

I've been an intermediate pilot recently enough that I can still remember being confused why I got such a low score in my cloverleafs in Intermediate at the Northwest Regionals.  When I asked the judge (and convinced him that I wasn't just challenging his judging!), I learned that my cloverleafs were scrambled.  I didn't believe it, but I really looked on my next flight, and, yup, my cloverleafs were scrambled.  I still don't get them perfect every time.

If you look at the rulebook picture, you'll see that all of the loops of the cloverleaf kiss, either on the 42-degree line, or on a vertical line at the center of the maneuver.  That's what you want to achieve.  I do this in two ways: by making sure that I visualize that cross (or at least pick out references to it as I fly), and by having a feel for how long the straight sections need to be, both in length in the air, and in how long they take. 

I wish that I could say that I was good enough that I could visualize that vertical line before I start my first loop and just kiss it -- I can, now, about 50% of the time (and keep in mind that I'm flying under-expert, so I'm supposedly pretty good).  The rest of the time I note where my first loop goes vertical, and I keep that in mind.  Then I try to locate all of my other loops to kiss that line.  Regardless of where you wanted to put that line initially, once you do that first loop you've established where it needs to be, so unless you're a better pilot than me and can fly up to that line consistently on the first loop, be ready to note it's position when you're flying, and find a reference mark.

Having that vertical line in mind helps me to improve my next clover.  For the clover that I'm flying at the moment, the best gauge I have to follow is that I need to make that first loop perfect, and then I need to fly a straight line that is as long as a loop is large (or, to be more mathematically precise: the line needs to be exactly one loop diameter).  Then I need to start flying the first outside 3/4 loop.  If I nail it, then it'll just automatically hit the line.  If I'm close, and if I'm ahead of the plane, I can make minor adjustments starting at the downward leg of the loop.  Follow exactly the same process for the remaining two 3/4 loops, always trying to return to the vertical and the 42-degree line.

That's how you do it in an ideal world.  The second thing that's going to screw you up for this, and for getting your horizontals horizontal, is fear.  For most of us, if we get rattled in a maneuver we tend to do everything too soon.  This applies to the clover -- come into it nervous, and it'll be very hard to wait long enough on that horizontal line to get the crossing right.  The only two things that I can suggest to alleviate this are, first, practice a lot.  If you're really serious, then at least every once in a while you should dedicate entire flights to  individual maneuvers -- just round loops, just square loops, just wingovers, etc.  If you really want to get the cloverleaf right, then on some practice flight, to your best takeoff, then do a dozen clovers, then do your best landing.  By that last cloverleaf, you should be doing very well.

The third "thing" that's going to screw you up is all of the things already covered for round maneuvers.  See Brett's postings on "lazy hands".  Everything that shows up in loops there will show up even worse in the clover, so you want to pay close attention.

[Tim Wescott]

Rising "horizontals".

Doing a cloverleaf with horizontals that rise truly offends me both as a pilot and a judge.  This is unfortunate, because know that I do it all the time.  The picture illustrates what I mean, just for the exit from the first loop -- but usually, if you do this on the first loop, even if you see it you're doomed to repeat it coming out of the third.  The picture looks extreme, and it is -- but I've seen clovers that look like that in competition.

I should mention here that this is a problem that everyone does, at least from time to time, and to some degree.  The difference is that Paul Walker or Dave Fitzgerald may rise a few inches on a bad day, while some of the truly bad examples of this will have a line that rises at 20 or 30 degrees.  As a judge and spectator I very rarely see a falling line here (and I don't see straight lines nearly as often as I'd like).

Most of the time, the immediate cause of the rising line is that the pilot gets to the end of the first loop, and realizes that they don't feel at all comfortable with the amount of room they have to do the second 3/4 loop.  Starting a loop at the top is always scary, and starting one low is scarier yet.  So, they come out of that first loop in a climb.  I suspect that for people who only rise a little bit that there's something about the geometry of the loop, or the way we visualize the "cross" that we have to fly to, that makes us come out a bit late, and thus rising.

By the time that you're at the end of that first loop and starting to get anxious about your altitude, it is too late.  This leads to the biggest error that I see in the cloverleaf, and it's one that nearly everyone does -- they start the thing way too low.  I'm not sure how often it's deliberately too low, from misjudging how little difference there is between 45 degrees and 42 degrees, and how often it is too low because it's hard to gauge 45 degrees at all.  But watching people fly, I see clovers routinely being entered as low as 35 degrees or so off of the ground, and sometimes lower -- do that, and you'll mess up the whole maneuver.

I think that most people remember that they're supposed to enter the clover somewhat lower than the 45 degree line, and vastly over-do.  I'm also pretty sure that most people aren't actually certain where 45 degrees is, and that this amplifies the problem.

If you're flying on 60 foot lines, flying at 42 degrees puts your plane about 2 1/2 feet lower in altitude than flying at 45 degrees.  That is all.  Unless you're really good, you can't gauge your altitude that well when you're flying at 45 degrees, much less fly exactly 30 inches lower.A second, possibly less important reason, is that people (me too, alas) tend to do their top loops too small.  Small loops are fast, and imprecise, and because the airplane is really being taxed by doing a loop at altitude, unpredictable.  Add to that any fear of being too low, and you tend to come out of the loop late, and rising.

For good intermediate pilots (who've gotten past the worst of the "Scrambled" clovers) up through Advanced (and, sadly, into Expert), here's the story that I see:

• You start the maneuver "lower than 45", because that's what the rule book says -- only you're way low
• You do a loop that's probably too small, and certainly not too big.  At the end of it you realize just how close to the ground you are, and you exit a bit late, and rising.  (I can't speak for everyone, but I know that I've been at that decision point and thinking "oh s*** the ground is awfully close!" -- and came out rising.
• You probably come into the third loop rattled, or at this point you're just making the thing symmetrical.  You do the SAME THING at the bottom of this loop (sometimes people will just get one or the other side rising -- usually, though, they're symmetrical about it)
• You finish, and get a lower score than you could

My advice, then, is that unless you're good enough to get into the top 20 at the nats, completely forget about 42 degrees.  Just establish a line at your best guess of 45 degrees, and stick to it.  I can't emphasize this enough -- try to put your horizontal line at exactly the same altitude as the intersections of your vertical eights, and the tops of your loops (these are all the same altitude, yes?).  Even if you can gauge 45 degrees accurately, doing an otherwise perfect clover starting at 45 degrees is just going to make the whole thing a tiny bit bigger, which is going to make it that much slower, that much smoother, and that much more in control.  Anything you lose in the judges noticing that it's a bit small is going to be entirely swept away by what you gain in accuracy and smoothness.

As part of this, learn to gauge 45 degrees.  In one of his columns, Allen Brickhaus showed a gizmo that would give you a 45 degree sight line.  You'll feel really stupid spinning around in the center of your control line circle with it, looking up at 45 degrees -- but you'll also learn how do judge where 45 degrees really is, and thus be able to hit it consistently.  Get the gauge, experiment with it, and you'll know why I think you shouldn't worry about the difference between 45 and 42 degrees!

Finally, re-read the bit in Brett's post about the hourglass.  You want the tops of your clovers to kiss the same "wingover" line that the hourglass rides along.  If you're not getting back that far, then your upper loops are too small, and you're likely setting yourself up for poor horizontals (and possibly bad intersections).

[phil c]

The scrambled cloverleaf is what I see most when judging or watching.  Even among experts it's way common, although not quite that exaggerated.  If I'm judging and see a pilot get the intersection in the middle and the four loops around it he gets a good score even if they are wobbly or messed up by the wind.  It's really bad on a cloudless day or a site with a low horizon.  That makes it very hard to keep the center in one spot and still looking high enough to get the upper loops near the wingover line.

[Igor Burger]

Tim, the problem is, that even definition of the 4L is not so well written. Geometrically correct 4L (means 4 equal loops fitting between level and wingower and touching as requested) have tanget points of upper and lower loop at 42 degrees, however the lowest point of upper loop is LOWER that that, somewhere at 38 degrees or so. So if you enter 4L at requested 42 degrees (it is in FAI definition, I am not sure if also AMA) then you are too high for proper 4L. So your picture seems to be well done for nice 4L, unfortunately not following rules requested entry at 42 degrees :- )))