Flight B/C

[joshdaposh]

Hello, I recently tested my FF kit Division C on.94 rubber and 100 winds. However, it climbed really fast and hit the ceiling a lot. I got the recommendation to find the max amount of wind for my ceiling and back off a couple of winds at the end but I feel like I would lose flight time from that. Are there any other solutions where I don't have to adjust the number of winds but instead make my turn radius wider or decrease incidence?

[bjt4888]

Hello, I recently tested my FF kit Division C on.94 rubber and 100 winds. However, it climbed really fast and hit the ceiling a lot. I got the recommendation to find the max amount of wind for my ceiling and back off a couple of winds at the end but I feel like I would lose flight time from that. Are there any other solutions where I don't have to adjust the number of winds but instead make my turn radius wider or decrease incidence?

Josh,

We'll need some more information to give you good advice. Please supply the following:
1. center of gravity location (measure with motor attached and measure as a distance from the wing trailing edge).
2. wing incidence measure
3. left wing washin measure (eyeball this; is it about 1/4", 3/8" or 1/2")
4. stabilzer tilt measurement
5. rudder offset measurement (for FF kit this is the stabilizer offset angle).
6. climb height
7. length and weight of the rubber motor
8. maximum torque that the rubber was wound to
9. exact number of backoff turns
10. launch torque value for the flight

Also, you will advance in flight duration rapidly if you read all of the other posts in this thread. This will only take you about 30 minutes, but you will see that especially the back and forth between Pumptato-cat and me and a couple of others will teach you a lot about the event and may even answer your questions.

Great job getting your airplane built and flight testing started.

Brian T

[Delfri1]

Hello, I really appreciate this thread, I'm a new coach for a JV flight team: B. We have our first invitational coming up. Has anyone had any luck finding the required box? We already damaged the plane once in the wind and have a box that works but is too large for competition. If anyone had any luck with this let me know, purchasing one is my preference.

[coachchuckaahs]

Very unfortunate that teams in your region don't take the learning (and fun) opportunity to spend more time on the flight event.

Agreed. Actually, I don't know that it's that they're not taking the time, as they have designed and built their airplanes themselves, or built from a kit. It's just obvious that they don't have a basic understanding of the principles of flying an airplane like this. I know that in my first year of coaching high school indoor free flight (which was a TSA event) I didn't know what I was doing, at all, and we had a 35 second flight time (in which we won first place because no other team was able to get their airplanes off the ground). I didn't know how to properly wind a motor, or that the turn was mostly controlled by the stabilizer tilt, or how to match a motor to a propeller. We based our plane off of a Hanger Rat, as it showed up first in a Google search, and I had to call a teacher over from the junior high to help me tune it because he flew radio controlled airplanes and I thought some of that knowledge might translate. That's how we got 35 seconds.

The knowledge is so specific and specialized to this kind of airplane. It's also spread out over 4 decades of non-searchable Indoor News and Views photocopied 'zines. High school students without a coach who has studied and understands the principles of indoor free flight are at a real disadvantage. I sometimes think I would like to put together a website that breaks everything down about the physics of flying these airplanes, winding the motors, construction techniques, and all specifically for Science Olympiad and TSA events. It would be a lot of work, but it would narrow the gap between teams who have a knowledgeable coach and those who are starting from scratch, with no base-level knowledge. I keep saying I'm going to put on a flight clinic for my local teams, but I'm already maxed out on time and I want to redesign our tandem stabilizer with a camber of 2.5% instead of 4% so it provides less lift in an effort to reduce decalage.

Brian:

Consolidating resources for entry into indoor flying is something we are trying to do in support of SO. You can find a start at https://freeflight.org/join-learn-fly/science-olympiad/. We are always open to posting resources generated by other coaches and mentors, as you have stated. Please check this out, and if you see areas that are lacking, please let us know or offer links or resources.

Thanks
Coach Chuck

[jander14indoor]

Hello, I really appreciate this thread, I'm a new coach for a JV flight team: B. We have our first invitational coming up. Has anyone had any luck finding the required box? We already damaged the plane once in the wind and have a box that works but is too large for competition. If anyone had any luck with this let me know, purchasing one is my preference.

Unless you've bought one of the kits that requires a maximized box (in which case check your kit provider) the whole point of the dimensions in the rules is that you can go to any office supply store and buy a 'standard' file or banker's box. For div B that's one of the long boxes, for div C, the short boxes.
Example:
Div B https://www.staples.com/Staples-Medium- ... uct_690751
Div C https://www.staples.com/Bankers-Box-Bas ... uct_761342

Of course, CHECK THE DIMENSIONS yourself, but these should work.

Jeff Anderson
Livonia, MI

[coachchuckaahs]

Jeff:

The listed Staples box shows a length dimension on the link you gave as 25.12". This is 63.8cm, whereas the rule limits length to 63cm. I do not know if this is a mistake in the rules or the Staples box does not qualify.

Students: It is your responsibility to verify your box meets the rules! I am hearing that 50% or more of boxes in early events are exceeding dimensions.

Coach Chuck

[pumptato-cat]

Definitely listen to what Coach Chuck said-I attended an invitational a while back and had to use a handmade box. If you're making your box, having the panels of the box cut as close to perfect as possible is so important. I found that if I measured at a certain point in the box, it was well within rules, but at a different point it was almost exactly the maximum dimension. The sides must be straight and perpendicular at corners.
I honestly wish ESs would provide a box, I feel like there's so many ways this could go wrong-including cheating, measurement issues, etc.

[jgrischow1]

I recently supervised Flight at a a small-to-midsized invitational. Some observations:

-Only two teams (both from the same school) knew what they were doing and finished in 1st and 2nd with times in the 1:20s.

-It was clear that this was many if not most kids' first in-person invitational and first scioly flying experience.

-Decent mix of J&H, FFM, and Guru. A few gliders and paper airplanes as well.

-The long banker box was used by many and does indeed fit the dimensions.

-On the other hand, almost half the students had boxes that exceed the dimensions. Perhaps unwisely, but given this was an early season invite, I made the blanket decision to scold the students but allow all boxes as long as the plane would have fit in one of the required size (which all did.)

-Many did not have logs completed...most common issue: no front cover page. (Yes, students should be reading and re-reading the rules, but I feel as though burying the front cover page requirement after a long section about 3D printing might be contributing to some of the issues.)

-Most students gave no thought to where they were standing and just moved a few feet from my check-in table (which was in the corner of the gym) and launched. Predictable results ensued.

-Many teams did not come prepared with ballast, spare parts, glue, etc. A few didn't have winders!

-We had some nice instances of sportsmanship with other teams loaning glue and winders.

-Most teams only checked in one rubber motor.

-Multiple teams were using baby oil as lube. I'm pretty sure that's petroleum-based and a big no-no (the experts are welcome to correct me.) One team _stored_ their rubber in their baby oil lube bag.

-Most teams, even with kits, had no idea how their planes were going to fly and weren't great at trimming, troubleshooting, problem-solving, making adjustments, etc. A few hours spent on these forums and watching the videos and learning from Jeff, Chuck, Brian, Josh, etc. would have been quite helpful.

-Multiple parents were way too eager to be handling their students' devices. One very nice young lady had trouble flying her plane, and after her turn, her father came over and was soon able to get it flying in nice circles. Big red flag.

-I remembered to bring a helium balloon for once (don't currently have the budget for a collapsible pole) but didn't have to use it. No planes got close to the ceiling.

[pumptato-cat]

jgrischow, thank you for that useful information! Was the AC turned on? And do you mind sharing the longest flight you've seen at any competition this year?

[jgrischow1]

jgrischow, thank you for that useful information! Was the AC turned on? And do you mind sharing the longest flight you've seen at any competition this year?

Air was off as far as I could tell. We've only been to one other competition and I didn't record any times from that one.