Wright Stuff C

[CrayolaCrayon]

We just competed in State today, and I was an assistant ES. Thought I would pass on a few observations:

• The LOG BOOK is not just an exercise. It is DATA that you can use to learn and perfect your flying. In order to be useful, it must be repeatable data! That is why torque meters and accurate turn counts are important.
  Coach Chuck

That can't be emphasized enough. Consistency is the most crucial element of success.

[jander14indoor]

Spare parts. Agree with most comments, typically allowed, perhaps with a reinspection, BUT, it is pretty much at the discretion of the event supervisor. As long as they are consistent, not even very appealable.
So, if you want an official position, FAQ time.
Until one is posted, plan to work both ways. Have two GOOD planes and be prepared to use them without major replacements. But have spare parts and know how to use them efficiently, if allowed AND if needed.
In general, this is good coaching. If you aren't sure how an ES will rule on an ambiguous point, be prepared to do well BOTH ways.

Jeff Anderson
Livonia, MI

[Polar]

When constructing a 2/3 partial motor stick, I know it should have a weight equal to 2/3 of the weight of the rubber band. However, if I plan to test using many different weights of rubber, would I have to construct various partial motor sticks each with varying weight? Or could I add clay to reach the 2/3 mark?

Thanks in advance.

[coachchuckaahs]

Polar:

If you are simulating 1/3 or your anticipated rubber, use a 2/3 stick. Then change the mass to equal 2/3 of the full rubber, or twice the 1/3 rubber each flight.

Another way to do it is test with same piece of rubber, but change stick mass and length each flight to simulate various full rubber sizes.

Coach Chuck

[Airco2020]

We just competed in State today, and I was an assistant ES. Thought I would pass on a few observations:

• The vast majority of FFM kits that flew well exhibited varying degrees of dutch roll (oscillating roll). A good fix is slightly increased vertical fin area. It does not take much.
  
  
  Coach Chuck

We have some dutch roll on the FFM model. Do you suggest building our own new vertical fin or is there a simple way to add a little to the FFM model? When you say "does not take much" can we just add a little balsa fin to the to or maybe a small stiff piece of paper?

[klastyioer]

We just competed in State today, and I was an assistant ES. Thought I would pass on a few observations:

• The vast majority of FFM kits that flew well exhibited varying degrees of dutch roll (oscillating roll). A good fix is slightly increased vertical fin area. It does not take much.
  
  
  Coach Chuck

We have some dutch roll on the FFM model. Do you suggest building our own new vertical fin or is there a simple way to add a little to the FFM model? When you say "does not take much" can we just add a little balsa fin to the to or maybe a small stiff piece of paper?

i would just build your own, it doesnt take long and it honestly could be a larger square if you were being that lazy

a 7x7 cm square would work fine

[coachchuckaahs]

When we were first testing in September, using old wings from 2017, we had dutch roll. We added a couple of pieces of tape between the two posts for our tail stabilizer, and the roll was gone completely. On that design the stab was probably about an inch or so below the tailboom.

You could experiment by gluing or taping on a bit of card stock, or even just tape. Then when you find what works, build a new fin if time allows.

In talking with Dave, it sounds like you can balance dutch roll against spiral dive by adjusting the wash-in of the left wing. Too much wash-in, dutch roll. Not enough, spiral in. With our design with a larger fin, we have not seen this sensitivity. So try both approaches.Dave indicates there are details in the instructions concerning the proper amount of wash in, and your observations if and adjustment is needed.

Coach Chuck

[newflight]

what is the better combination for propeller and rubber band? less pitch with thinner rubber band or larger pitch with thicker rubber band

[coachchuckaahs]

You will need to experiment. There will be an optimal pitch, given the blade shape and the diameter, as well as the airplane (including total weight you are carrying). This is the essence of the contest!

For a give prop configuration, you will optimize the rubber. Then change the prop and do it again. If you take good data, you will see trends and will be able to come to a reasonable conclusion.

We have over 300 flights so far this year. It takes persistence to find optimums. Then you try a new blade shape, and it works better, and you start again!

Generally, higher pitch than "expected" is found, IMHO. However, you have to be careful about over-pitching and stalling, especially when balancing the variables of a flaring prop as well. And, the helical pitch of the prop should be close to the pitch setting (static or dynamic) as well.

Sorry, no simple answer here.

Coach Chuck

[Polar]

So a question about test flying. Say I fly at noon, but want to get to the area some time before hand at around 10 to do some test flying. If my partner for that event is not available until 11:30, am I allowed to use one of my team's alternates to help me test fly up until 11:30, even though they are not my official partner?