Wright Stuff C

coachchuckaahs
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Re: Wright Stuff C

Postby coachchuckaahs » May 15th, 2019, 3:27 pm

Blush!

Really Coach Brian, I have only 4 years, and my team's success comes strongly from your remote mentorship, both here and on Hip Pocket.

Like the Michigan model, I am doing what I can to make my State more competitive. My team has done VERY well over the last few years, but the rest of NM struggles with flying events. This year I presented an hour at our annual SO Teachers' seminar, and it was well received (PM me if you would like the slides). This year I also retired, hoping among other things to pick up some schools in the fall for more direct mentorship. I would LOVE to see my State become competitive across the board in the flying events. Getting the foot in the door is the first big step.

My strongest goal, though, is to inspire these young minds to pursue aviation sciences. This year I feel I have done that in spades. I have 6 kids wanting to do WS, and only 3 team slots (and only 2 get to compete). These kids do not want to stop flying. Ever. It is hard to get them to pack up to leave on time! This is most gratifying. We went to Round Valley, and they flew to the closing horn every day (3 days of flying). This was the most fun I have had in aviation, ever.

So, it is key people like Brian, and all the other less vocal coaches, that make a State like Michigan successful in flying events. Brian has been an inspiration to me, and I am always saying to my teams at testing, "Brian said..."

I was trying to work up a student seminar for Nationals. It may not happen this year because we got a late start, but maybe. The AMA members in the indoor community enthusiastically supported the concept and were ready to give of their time to meet and greet the student flyers. This indicates the indoor community WANTS to reach students. If you have not been mentored by an indoor flyer, consider contacting the AMA and trying to find a local indoor enthusiast that would help. AMA, after all, is a sponsor of SO flying events.

Coach Chuck

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Re: Wright Stuff C

Postby newflight » May 16th, 2019, 7:44 pm

how does temperature and humidity affect flight time? Tonight, my gym was really warm and much more humid. air is even condensed into water on floor. it seems it makes flight shorter. is this true?

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Re: Wright Stuff C

Postby newflight » May 16th, 2019, 8:12 pm

what is the best way to control descending rate? my flight rise up really slow, about half of the time is to rise, then cruise for about 30~35% of total flight time, descending time is only about 15~20% of total flight time

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Re: Wright Stuff C

Postby Rossyspsce » May 16th, 2019, 8:13 pm

how does temperature and humidity affect flight time? Tonight, my gym was really warm and much more humid. air is even condensed into water on floor. it seems it makes flight shorter. is this true?
don't quote me on this, but from my data I think humidity causes shorter flight times since the air is more humid, it means there is more water in the air itself. So from this the weight of the air is heavier, meaning the prop of your plane needs to push heavier air, which burns energy faster, making flights shorter. As for temperature, I found that it had a lower effect on flight times than did humidity, but if the average air temperature was relatively warm, times tended to become longer than compared to cold. I observed this difference the most at ggso, where the temperature was higher and the humidity was lower than my primary testing area

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Re: Wright Stuff C

Postby klastyioer » May 16th, 2019, 8:38 pm

how does temperature and humidity affect flight time? Tonight, my gym was really warm and much more humid. air is even condensed into water on floor. it seems it makes flight shorter. is this true?
don't quote me on this, but from my data I think humidity causes shorter flight times since the air is more humid, it means there is more water in the air itself. So from this the weight of the air is heavier, meaning the prop of your plane needs to push heavier air, which burns energy faster, making flights shorter. As for temperature, I found that it had a lower effect on flight times than did humidity, but if the average air temperature was relatively warm, times tended to become longer than compared to cold. I observed this difference the most at ggso, where the temperature was higher and the humidity was lower than my primary testing area
lmao wait what i thought that humidity helps the plane like if the air is warmer rather than humid (word fits better in this context), it will favor the planes flight. idk if im right its just a hypothesis cause whenever we test when its warm the air currents are more still than when its cold which usually suggests the vents were on, its cold outside, or the doors were open and then closed but all the currents got wacko. i do agree w ur "theory" (my bio teachers gonna kill me for saying that in the wrong context), though i dont even know if im right sooo
it's not about the medals; go out there and have fun. make progress, learn a few things, have one heck of a time, because that's all that matters.

Builder Cult >:)

'17 - Towers, WS, rocks
'18 - Towers, WS, Mystery Arch, road
'19 - WS
'20 - WS, Boomilever

Rossyspsce
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Re: Wright Stuff C

Postby Rossyspsce » May 16th, 2019, 8:56 pm

how does temperature and humidity affect flight time? Tonight, my gym was really warm and much more humid. air is even condensed into water on floor. it seems it makes flight shorter. is this true?
don't quote me on this, but from my data I think humidity causes shorter flight times since the air is more humid, it means there is more water in the air itself. So from this the weight of the air is heavier, meaning the prop of your plane needs to push heavier air, which burns energy faster, making flights shorter. As for temperature, I found that it had a lower effect on flight times than did humidity, but if the average air temperature was relatively warm, times tended to become longer than compared to cold. I observed this difference the most at ggso, where the temperature was higher and the humidity was lower than my primary testing area
lmao wait what i thought that humidity helps the plane like if the air is warmer rather than humid (word fits better in this context), it will favor the planes flight. idk if im right its just a hypothesis cause whenever we test when its warm the air currents are more still than when its cold which usually suggests the vents were on, its cold outside, or the doors were open and then closed but all the currents got wacko. i do agree w ur "theory" (my bio teachers gonna kill me for saying that in the wrong context), though i dont even know if im right sooo
aren't warm air and humidity different? Like humidity is the amount of water actually in the air. Also warm air and humidity are not mutually exclusive. Warm air can occur in very dry places, low humidity, like Arizona or very wet areas, high humidity, like Lousiana

BigBootyBason
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Re: Wright Stuff C

Postby BigBootyBason » May 16th, 2019, 8:56 pm

I mean if it was humid wouldn’t the plane gain weight and drop mid air?

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klastyioer
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Re: Wright Stuff C

Postby klastyioer » May 17th, 2019, 4:00 am


don't quote me on this, but from my data I think humidity causes shorter flight times since the air is more humid, it means there is more water in the air itself. So from this the weight of the air is heavier, meaning the prop of your plane needs to push heavier air, which burns energy faster, making flights shorter. As for temperature, I found that it had a lower effect on flight times than did humidity, but if the average air temperature was relatively warm, times tended to become longer than compared to cold. I observed this difference the most at ggso, where the temperature was higher and the humidity was lower than my primary testing area
lmao wait what i thought that humidity helps the plane like if the air is warmer rather than humid (word fits better in this context), it will favor the planes flight. idk if im right its just a hypothesis cause whenever we test when its warm the air currents are more still than when its cold which usually suggests the vents were on, its cold outside, or the doors were open and then closed but all the currents got wacko. i do agree w ur "theory" (my bio teachers gonna kill me for saying that in the wrong context), though i dont even know if im right sooo
aren't warm air and humidity different? Like humidity is the amount of water actually in the air. Also warm air and humidity are not mutually exclusive. Warm air can occur in very dry places, low humidity, like Arizona or very wet areas, high humidity, like Lousiana
lol yeah sry i wrote that rly late idk what i was saying oops screw high school for giving me sm homework
but yeah they're diff and humid air causes the build to get heavier
which is why people in boomi put silica gels in their boxes at times
it's not about the medals; go out there and have fun. make progress, learn a few things, have one heck of a time, because that's all that matters.

Builder Cult >:)

'17 - Towers, WS, rocks
'18 - Towers, WS, Mystery Arch, road
'19 - WS
'20 - WS, Boomilever

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Re: Wright Stuff C

Postby jander14indoor » May 17th, 2019, 7:46 am

Warm air helps the rubber store more energy (to a point, and possibly more correct to say cold rubber stores less energy).
Humid air, in addition to the weight gain, tends to soften the balsa, affecting trim and motor stick bending. And its not really the humid air, but the resulting moisture increase in the wood.
Humid (denser, the key point) tends to give more lift (increasing flight time) than dryer (less dense) air. And its the density that counts. Of course it also affects drag, so I'm not sure what the overall trade off is.

And it can certainly affect competition. When National's was at George Washington University in 2008, the weather was miserable, typical HOT, MUGGY day in Washington DC. Air was off in the gym we used and by the end of day it was nasty inside. You could see if affecting teams, this was a day that waiting till the end of the competition did NOT pay off. Teams that got good times practicing early in the day couldn't manage near the same time by their official flights at the end of the day.

Jeff Anderson
Livonia, MI

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Re: Wright Stuff C

Postby BalsaFerret » May 18th, 2019, 5:12 pm

Hey guys, although nats is not far away and people are finalizing their flights, I still don't feel like I've fully grasped the details and want to ask some (basic) questions:

1) How do you know when to adjust incidence/moving cg/testing different torques to maximize times - is it just through testing all trims to find the optimum?
2) When matching rubber/prop, do you fly the same trim when testing the different combos or is it fine to make tiny changes to the trim to maximize times?

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Re: Wright Stuff C

Postby bjt4888 » May 19th, 2019, 3:51 pm

Balsa,

We generally start testing by selecting a conservative CG based upon the neutral point and a slightly excessive decalage angle (difference between the wing and stabilizer incidence angles). We fly this setup, maybe slightly reducing wing incidence if stalling, with a variety of propellers (usually increasing pitch gradually) and a variety of rubber densities andmotor lengths. Once we have this trim setup flying well, we will start pushing the CG back till stalling (or,intense case of this year’s tandem, mushing and wandering) and then move the CG jus forward of this point or reduce the wing incidence, or try both adjustments separately on different flights.

We continue iterations of the above till changes stop increasing duration or till too unstable to survive air disturbances or ceiling hits.

Good luck and have fun at Nationals.

Brian T

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Re: Wright Stuff C

Postby BalsaFerret » May 19th, 2019, 8:38 pm

Balsa,

We generally start testing by selecting a conservative CG based upon the neutral point and a slightly excessive decalage angle (difference between the wing and stabilizer incidence angles). We fly this setup, maybe slightly reducing wing incidence if stalling, with a variety of propellers (usually increasing pitch gradually) and a variety of rubber densities andmotor lengths. Once we have this trim setup flying well, we will start pushing the CG back till stalling (or,intense case of this year’s tandem, mushing and wandering) and then move the CG jus forward of this point or reduce the wing incidence, or try both adjustments separately on different flights.

We continue iterations of the above till changes stop increasing duration or till too unstable to survive air disturbances or ceiling hits.

Good luck and have fun at Nationals.

Brian T
Thanks, Brian for clarifying my questions with your own practices, I really appreciate it. I'll apply these in my upcoming, short but important flying sessions.

Though, I was wondering how you calculate the NP - do you have a special spreadsheet just to calculate it because I've seen some people use calculators to find the NP and SSM, but I can't seem to find one that works or don't know how to make one myself?

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Re: Wright Stuff C

Postby bjt4888 » May 20th, 2019, 6:29 am

Balsa,

We use the Bernie Hunt NP/Design spreadsheet. Fern Rash also has published a good one. Both are available in the Yahoo Group “Indoor_Construction” in the Files section. Bernie’s sheet doesn’t calculate CG perfectly for heavy airplanes like we use for SO but we “trick” the spreadsheet by entering the ballast location different than actual in order to have the sheet calculate the CG correctly and thereby show the SSM correctly.

If you have detailed questions about use of the sheet, spend me a PM.

Brian T

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Re: Wright Stuff C

Postby bjt4888 » May 20th, 2019, 7:27 am

Fred Rash, not Fern Rash.

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Re: Wright Stuff C

Postby BalsaFerret » May 21st, 2019, 8:39 am

Balsa,

We use the Bernie Hunt NP/Design spreadsheet. Fern Rash also has published a good one. Both are available in the Yahoo Group “Indoor_Construction” in the Files section. Bernie’s sheet doesn’t calculate CG perfectly for heavy airplanes like we use for SO but we “trick” the spreadsheet by entering the ballast location different than actual in order to have the sheet calculate the CG correctly and thereby show the SSM correctly.

If you have detailed questions about use of the sheet, spend me a PM.

Brian T
Thanks sm again Brian, I'll try to use them and gather some accurate data.


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