Flight B/C

[danxmemes]

So I have a question about plane building, is there any way to have a large wing chord size (lets say 5-6 inches) without drastically reducing the stability of the plane and its ability to recover? So far its only been one or the other for me. thanks

[coachchuckaahs]

Dan

I assume you mean C division? In B, 5" cord is no problem. In C, it is a challenge with critical trim. I would build very light, especially the tail end, and then put as much ballast at the front as needed to get to 8g. You should be able to build at a 5g if careful. Then put the wing as far forward as you can to get the longest tail moment possible.

This will make the best stability out of a tough design. However, you probably still want to shoot for a no touch flight, as stability will still be marginal. I think the extra wing area is probably worth it, but you are walking a fine line! No guts no glory! Making consistent no touch flights requires a lot of testing.

Coach Chuck

[danxmemes]

Dan

I assume you mean C division? In B, 5" cord is no problem. In C, it is a challenge with critical trim. I would build very light, especially the tail end, and then put as much ballast at the front as needed to get to 8g. You should be able to build at a 5g if careful. Then put the wing as far forward as you can to get the longest tail moment possible.

This will make the best stability out of a tough design. However, you probably still want to shoot for a no touch flight, as stability will still be marginal. I think the extra wing area is probably worth it, but you are walking a fine line! No guts no glory! Making consistent no touch flights requires a lot of testing.

Coach Chuck

Thanks!

[Vive]

Hello!

The Nationals website says the curtains will be down around the basketball court Don't we all see this as a risk? Can this event be run with Curtains open? to avoid any crashes?

"FLIGHT: This will be held on a full basketball court with curtains down, a basketball court is 94’x50′. The ceiling height is 27′. A/C is scheduled to be off.
Starting Saturday morning (7:00am) there will be an area of Heskett Center courts open for practice. This will not be monitored and is at the team’s own risk for crashes. "

https://scienceolympiad2023.com/index.php/divison-b/

Thanks,
V

[jander14indoor]

The gym is a multi court type. Different events will be run in different courts. Curtains are to manage crowd movement and separate events.
Depending on the curtain type, I wouldn't expect them to cause problems. 94X50 should be enough room to turn without hitting the walls, also break up flow along a BIG gym space so maybe reduce drift.
I ran the U of Mich invitational earlier this year in such a gym. We had both B and C without a problem. I think one plane managed to sneak around the curtain and we just followed it to time, no big deal.

Jeff Anderson
Livonia, MI

[jaspattack]

Hello!

The Nationals website says the curtains will be down around the basketball court Don't we all see this as a risk? Can this event be run with Curtains open? to avoid any crashes?

"FLIGHT: This will be held on a full basketball court with curtains down, a basketball court is 94’x50′. The ceiling height is 27′. A/C is scheduled to be off.
Starting Saturday morning (7:00am) there will be an area of Heskett Center courts open for practice. This will not be monitored and is at the team’s own risk for crashes. "

https://scienceolympiad2023.com/index.php/divison-b/

Thanks,
V

I don't see how this would be any different from running it in a gym enclosed by walls. If anything, it'd be better so that if your plane does crash into the curtains it's a soft surface rather than a hard one.

They're likely just trying to keep flights in an enclosed space by separating the courts. I don't think it's really that big of a deal.

[bjt4888]

Hello!

The Nationals website says the curtains will be down around the basketball court Don't we all see this as a risk? Can this event be run with Curtains open? to avoid any crashes?

"FLIGHT: This will be held on a full basketball court with curtains down, a basketball court is 94’x50′. The ceiling height is 27′. A/C is scheduled to be off.
Starting Saturday morning (7:00am) there will be an area of Heskett Center courts open for practice. This will not be monitored and is at the team’s own risk for crashes. "

https://scienceolympiad2023.com/index.php/divison-b/

Thanks,
V

I don't see how this would be any different from running it in a gym enclosed by walls. If anything, it'd be better so that if your plane does crash into the curtains it's a soft surface rather than a hard one.

They're likely just trying to keep flights in an enclosed space by separating the courts. I don't think it's really that big of a deal.

Actually, in my experience coaching 16-20 students each year since 2008 (and completing about 8,000-10,000 test flights in that time) curtains are worse to hit than walls. An airplane that takes an indirect hit on a hard wall will often bounce back into the flying area a little. A curtain gives a little and "catches" the airplane like a net and even indirect hits often lead to a slide to the floor. Direct "t-bone" hits on either a wall or a curtain usually lead to slides to the floor; we will always try to catch these. All of the gyms that my teams practice in have curtains, so this observation is based upon lots of experience. Avoid the curtains.

I'm fine with the curtain down at Nationals though as it is important to protect the other event areas. Just fly carefully and conservatively on your first flight and observe other competitors if possible to determine drift and air currents.

Good luck to all at Nationals!

Brian T

[jaspattack]

Hello!

The Nationals website says the curtains will be down around the basketball court Don't we all see this as a risk? Can this event be run with Curtains open? to avoid any crashes?

"FLIGHT: This will be held on a full basketball court with curtains down, a basketball court is 94’x50′. The ceiling height is 27′. A/C is scheduled to be off.
Starting Saturday morning (7:00am) there will be an area of Heskett Center courts open for practice. This will not be monitored and is at the team’s own risk for crashes. "

https://scienceolympiad2023.com/index.php/divison-b/

Thanks,
V

I don't see how this would be any different from running it in a gym enclosed by walls. If anything, it'd be better so that if your plane does crash into the curtains it's a soft surface rather than a hard one.

They're likely just trying to keep flights in an enclosed space by separating the courts. I don't think it's really that big of a deal.

Actually, in my experience coaching 16-20 students each year since 2008 (and completing about 8,000-10,000 test flights in that time) curtains are worse to hit than walls. An airplane that takes an indirect hit on a hard wall will often bounce back into the flying area a little. A curtain gives a little and "catches" the airplane like a net and even indirect hits often lead to a slide to the floor. Direct "t-bone" hits on either a wall or a curtain usually lead to slides to the floor; we will always try to catch these. All of the gyms that my teams practice in have curtains, so this observation is based upon lots of experience. Avoid the curtains.

I'm fine with the curtain down at Nationals though as it is important to protect the other event areas. Just fly carefully and conservatively on your first flight and observe other competitors if possible to determine drift and air currents.

Good luck to all at Nationals!

Brian T

Interesting! I've never actually flown in a gym with curtains (and its been plenty of years since I did Wright Stuff) so that was kind of just a guess on my part. Good to hear from someone who's got more experience than me.

[ParekhPar]

Question for the group - we are excited about traveling to Wichita this week, but unsure how to transport our planes effectively for an 11 hour drive in their custom boxes. Seeing that the planes should travel deconstructed to avoid the wing getting crushed by the box sliding or jostling, any tips on padding the boxes / filler that would not damage the mylar and components? Thanks in advance!

[Astronomyguy]

For my state tournament (MD), the winning time was 2:03 from Poolesville High School. Centennial High School had 1:37 (going to nats), and Montgomery Blair had 1:30. No other teams had times over a minute.

I'm currently trying to help my school's nats team with their Flight as I'm more well-versed in the event than they are.

One of them built their own plane which is quite small (it was built to fit comfortably in the box without tilting) and flies very fast. It has a tendency to either climb extremely fast or roll. The winglets/vertical stabilizers are quite prominent (height is about 1/4 of the wingspan), the HS offset has 5 settings, and the CG is adjusted by a balsa block that slides along the motor stick. This was the plane that flew at states. I told them to put as much distance between the wing and the HS to maximize the tail moment, and after that was done the rolling.diving was fixed. I also told them to launch the plane tilted slightly to the right to counteract the roll from high torque.

With better winding technique and the higher nats ceiling, I think this plane can definitely break into the lower 2 minutes at least. The climb speed has been a problem (it hit the 30 ft Princeton ceiling with a flight time of around 1 minute), so I've added some pitch to their propeller and plan to teach them to adjust it accordingly. I also plan to teach them to use a torque meter.

The other one built a J&H Kit (they have 2 planes) and they can fly times of ~1:20-1:30 but are pretty inconsistent. One plane's recurring problem is its tendency to climb steeply (>60 degrees) before stalling. It also turns right sometimes. The turning right is definitely a sign of too much wing warp but it doesn't seem to have any. The other plane flies fine but could definitely be improved upon.

They currently have subpar winding technique and don't use a torque meter, so I'm planning to fix that. I'm hoping for them to break 2 minutes, hopefully 2:15 at nats to place high.

Let me know if this is good advice to share, and anything else. Obviously they have trim improvements to make but I'm getting them to learn winding and rubber as well.

By the way, what times do you typically need to place top 10 at nationals? What times do you need to medal? Last year, our flight flew around 90 seconds at nationals and placed 29. Do you think that this year's restrictions will tone down the times at nationals compared to previous years?