Dean Bird

My Feedback: (39)

Hello again to all the straight line fanatics around the globe!!

I'm planning on adding a new thread each Friday afternoon, except for the Friday before a contest. I'll be traveling those Fridays and won't be online.

In our last two threads, we've gotten the [link=http://www.rcuniverse.com/forum/m_3772719/tm.htm]annual maintenance[/link] done on our plane if we're going to fly last year's plane, and we've gotten a lot of information on how to start working on the "[link=http://www.rcuniverse.com/forum/m_3775092/tm.htm]setup[/link]" for our plane. As "shannah" said, the "setup" is never "a done deal", but we're on the way to having the most "perfect" flying plane possible.

The next item that is key to being competitive is the ability to read our Aresti diagrams. You can ask questions pretty quickly for each season's Knowns, but the ability to read Aresti becomes critical on contest weekends. Beyond the Basic class you'll be dealing with an Unknown and you'll likely be asked to call for someone else. You may be asked to be a caller for a judge.

At every contest there is always a pilot that makes a mistake in reading the Aresti and flies an incorrect Unknown maneuver. I was being chased at a contest in Las Vegas in 2004. I watched my competitor fly the nicest pull to a 45, a 2 of 4 point roll, then a 5/8 inside loop. Unfortunately, the maneuver should have been flown in the reverse, a 5/8 inside loop to a 45 down line with a 2 of 4 point roll on the 45 down line. I got the 1st place trophy that weekend!! To be your most competitive, you MUST be fluent in Aresti diagrams.

All the maneuvers we fly come out out of the International FAI catalog that is used in full scale aerobatics competition. That's why we're called "scale" aerobatics. Here's a link to the catalog of maneuvers. We'll use it later.

http://www.mini-iac.com/Portals/57ad...%20Catalog.pdf

So there's a BUNCH of possible maneuvers in there. Don't be overwhelmed. All of the stuff in there is used to create the sequences we fly. Right now, that's somebody else's job. Once they create the sequence, we have an Aresti diagram that we need to be able to read correctly. Before we go any further, read this "Aresti Made Simple" article from the IMAC website. We'll wait until you get done.

http://www.mini-iac.com/Portals/57ad...imple_2005.pdf

In nine quick-reading pages you've just learned all you need to know to correctly read an Aresti diagram!!

Here's the Aresti for the 2006 IMAC Basic sequence.

http://www.mini-iac.com/Portals/57ad...7/Bas-2006.pdf

Here's the Aresti for the 2006 IMAC Sportsman sequence.

http://www.mini-iac.com/Portals/57ad...7/Spt-2006.pdf

The Aresti diagram you print off from a website or get at a contest is just an illustration of the required elements of each maneuver. This causes a lot of confusion. Look at 2006 Basic maneuver #6.



Do we really fly it with an exit twice as low as the entry?

Take a look at 2006 Basic maneuver #8.



Should we put the 1/2 roll on the 45 down line below the altitude we entered the 5/8 inside loop?

Take a look at 2006 Sportsman maneuver #10.



Does it end on a 45 upline?

The answers to all those questions is "NO". We're just seeing how the software illustrated the maneuver. Regardless of how the maneuver is drawn on the paper, each maneuver begins and ends from horizontal (either upright or inverted) wings level flight flying either parallel to the runway or perpendicular (cross box) to the runway.

You see lots of other strange looking figures that the software has drawn when illustrating the sequence. If you have questions on what a maneuver is really supposed to be, you can find the "basic figure" in the Aresti catalog.

Let's talk about how to find that figure in the Aresti catalog. Using the 2006 Sportsman maneuver #10 again, look at the lower right hand corner of the Sportsman sequence in the second column next to "Fig 10". We see the maneuver has been constructed using these elements from the Aresti catalog.

8.52.3
9.1.3.2
9.1.1.3

The numbers in the third column in the bottom right corner of our sequence are the "k" factors for each of three elements from the catalog that were used to construct this maneuver. The fourth column is the total "k" for each maneuver which is just the total of the "k" factors for the elements used to construct the maneuver.

The first catalog number listed for each maneuver, in this case "8.52.3", is called the "basic figure". We're trying to find out what "8.52.3" really is since the illustration on our Aresti looks strange. Except for Family 9 figures, there are three parts of the catalog number for a manuever. The first is the "family" the maneuver is in, the second number is the "row" number the maneuver is pulled from in that family, and the third number is the "column" in that "row" from that "family". With "8.52.3" we can go to "Family" 8 in the catalog, then find row "52" in that "family", then go to column "3" in that row. The "k" factor for that "basic figure" is in the circle next to the manuever. We see a "k" factor of "12".

We see a "basic figure" that is entered from upright, has a required rolling element that ends up 180% of rotation different than where we started, has a 3/4 inside loop, has an optional rolling element on the vertical upline, and exits positive. Great!! We have a real good idea how this figure should start and finish. The only thing left is the two rolling elements that have been added to our "basic figure".

The first rolling element is the "9.1.3.2". The rolling element on the upline is a "9.1.1.3".

The figures in "Family" 9 have four parts to their catalog number.

1. "family"
2. type of rotation (slow, 2-point, 4-point, 8-point, spin, flick)
3. "row" - direction of underlying flight path
4. "column" - extent of rotation in mutiples of 90 degrees

What the FAI catalog calls a "slow roll" is just an aileron roll and does NOT have to be "slow". What the FAI catalog calls a "flick roll" is also called a snap roll. The different types of rolls are set up in tables.

Both of our rolling element catalog numbers start with "9.1", so they are slow/aileron rolls. We go to the "9.1" table for the "row" and "column". Our first roll element is entered from (row 3) horizontal flight and is a (column 2) half roll. The "k" factor is listed in the table is a "4".

The roll on the vertical upline is entered from (row 1) vertical upward flight and is a (column 3) 3/4 roll. The "k" factor listed in the table is a "10".

So now we know we enter 2006 Sportsman maneuver #10 from upright, perform a 1/2 roll, fly a 3/4 inside loop, perform a 3/4 roll on the vertical upline, and exit positive to upright wings level flight. Regardless of how strange it looks on the illustrated sequence, we know exactly how to fly it because we looked up each part of the maneuver by it's catalog number!!

We've got the maneuvers figured out and we're ready to fly them. We need to talk about a few other key points. The "Aresti Made Simple" article mentioned the solid and dashed lines on the flightpath. Solid is intended to indicate either upright or positively loaded flight. The dashed lines are intended to indicate either inverted or negatively loaded flight. You can use them as a clue, but don't worry about them too much. In many cases you'll being flying in an up or downline and the loading (solid or dashed) seems funny. As long as you came into the maneuver correctly and flew the correct elements, you're in the correct orientation.

Each maneuver is numbered and they must be flown in numerical order. Be sure you start at the dot with the maneuver number and end at the perpendicular line. Don't get a zero in that Unknown because you fly a perfect maneuver in reverse.

I'm going to quote from Page 10, Item "10." out of the Aresti catalog for this point. "All basic figures except Family 1.1 depict a flightpath that has looping portions. When such a looping element has at least 180 degrees of pitch, it is depicted in the diagrams as a curve. When it is less than 180 degrees, the element is shown as a 'corner'. Despite being drawn for convenience in this manner, all such 'corners' are to be interpreted as being flown in a continuous curve of constant and significant radius." All those square "corners" you see on the Aresti diagram are actually partial loops. Fly a "continuous curve of constant and significant radius" for every pull or push you fly to score your best.

The next point is that the sequence is only illustrating the required elements. You don't have to fly the cross box elements in the direction illustrated. In the 2006 Sportsman maneuver #4, a 1 1/4 positive spin is required.



If you're flying the "Form C" sequence (right to left), it is illustrated as a right spin and a cross box exit going out. You can absolutely do a left 1 1/4 turn spin and exit cross box coming in if you prefer. You have met the requirements for the maneuver. If you exit coming in, you'll just continue your sequence with a pull into maneuver #5, a 2 of 4 on the upline, you'll push over the top going out, execute a 1/4 roll to the right on the downline, and exit positive to the left side of the box. The same is true for the 3/4 roll on the upline in the 2006 Sportsman maneuver #10.



The 3/4 roll is illustrated as exiting cross box going out. This may be the preference of the CD for safety reasons, but you can 3/4 roll either way. As long as you exit positive (upright) going cross box, you've met the requirements for the maneuver.

That's it. Go back and re-read the "Aresti Made Simple". Pull a couple sequences and look up a strange looking maneuver in the Aresti catalog. Come back and read this thread one more time. You are now ready to tackle any Aresti diagram you see!! The 30 to 60 minutes you spend learning this will be a big step in making you more competitive in the future!!

Let us know if any questions come up as you apply your new knowledge.

Here's to another weekend of "perfect practice" for everyone!!!!!

Take care,

Dean Bird
Sun Valley Fliers
Phoenix, AZ

Brian_AZ

My Feedback: (2)

Thanks Dean,

This info really helps. I'm curious when the Sportsman sequence changed. I printed it when the final was released (early November?) but mine shows exit inbound after the spin. I know I can go inbound or outbound. Just wondering when/why it changed.

Brian

Tom Wheeler

This happens just about every year, after the proposed sequences become "official", the drawings are reviewed again and some changes (just from a graphic point of view) are made in the hopes to better visualize the sequence. This year, the ISC again reviewed each sequence and reposted them to the IMAC website. There was a “K� correction for Advanced, as one of the Snaps had the incorrect “K�. Please everyone go back to the IMAC website and make sure you have the latest Sequence drawing for your class. As a side note, Unlimited has the greatest graphical change, but there is no change to the sequence itself.

Regards,

Tom Wheeler
IMAC ISC member

Tony Fandino

My Feedback: (8)

Great job Dean,

To all who read this. You must be proficiant in reading aresti. This is a must to become successfull in IMAC.
Practice, Practice, Practice...... READ........ Practice, Practice, Practice. Another important issue to learn is the judging criteria
and by all means make out to the closest judging seminar offered by IMAC, this is also essensial



Tony Fandino

Dean Bird

My Feedback: (39)

Tom, thanks for answering Brian's question.

Tony can predict the future!!

Now that you know what maneuvers to fly, judging criteria will be next weeks topic. Everybody come back next Friday for the new discussion thread.

Talk to you then,

Dean