RC India

Alright everybody, went to do a maiden flight today, threw the airplane into the wind, the plane went straight up did a loop on its own and landed on the ground safely(luckily). So, i just want to know what all modifications are necessary to get my plane balanced. One obvious one would be to make it nose heavy, and i have to admit that its a bit tail heavy. But other than that what all things should i do? Should i hand launch it at 3/4th throttle or less? I will try and post the video as soon as i can figure out how to get the video from my cam to my pc. The other thing to note is that the wind here in kol was quite strong 2day, so how much of an effect does that have?

If its difficult to modify the plane physically, I think U can do a little throttle to elevator mixing. Am I right guys?

same thing happened to me before 5 yrs when i started RC ,if you u are sure with CG than check thrust angle it should be 3deg downwards and 2-3 deg towards right or else check the CG first! hope this helps! ;D

all the best for your next flight :thumbsup:

It really helps to do glide tests (see Ashta's video on the same) into tall grass on the ground.  For people who do scratch builds, I am not sure why this simple step is often not undertaken... is it the lack of such fields in their localities ? I am sure with some searching some kind of crop field can be found !

Positioning of battery is the simplest thing you can do to help correct CG issues.

anwar sir u r right..i did as u told for test glide.....unfortunately something was wrong with the design...so the elevators broke in the second glide.....but at last the plane flew well.... ......i seriously  test glides are really important if u r scratch building

Anwar uncle, the winds were really strong yesterday. Before my maiden flight, i did a glide test but couldn't get anything out of it because of the strong winds. But it landed on the ground tail first.

One more thing i would like to know is how important is the tail wing. Like for an example, i have a RTF cessna and it flies great. It has a wing span of 3ft and the tail wing is 16 inches. In my plane, the wingspan is 3ft 2inches and the tail wing is 8 inches. So does that also have an effect on the flight. So, do i also need to increase the size of the tail wing.

rohit,
always its a good idea to take the help of an experienced flier for the maiden. It will help to save your valuable effor.
Check your throws. It should be DRed to be the min required. Mind you most of the beginers crash is due to excess throws.
best regards
ashta

Ashta sir, the problem here in Kolkata is that i cant find any experienced flier flying in the field. Heard that many experienced fliers fly here at the Race course maidan at gate no.22. But found nobody. I have to admit that i rely heavily on this forum for any sort of help regarding this hobby because there is nobody to help here in Kolkata, feel completely lost, the only fellow flier i found here is Sethji. Regarding the throws, i couldn't do anything. As soon as i threw the plane it went straight up did a loop and landed(i reduced the throttle), i had no time to do anything with the controls, because things happened so quickly.

How much time did you spend on the sim before attempting the first flight ?  A trained (which includes self-trained) flier can do something in pretty much any situation.

This past friday at our field, there was a new flier from Lebanon.  He is a quiet family man, approaching the end of middle age.  Always interested in flying, he had bought a Trex 600 Nitro as his first RC model (a somewhat surprising choice, this happened before he got in touch with me).  He had bought a kit, along with a Futaba 7C 2.4Ghz radio.  He contacted me through the rcqatar.com website after he got the kit, and insisted that he wanted to build it himself (showing his passion towards the build part of the hobby).  I cautioned him that this is something to be done very carefully, and gave some tips on use of loctite etc.  He built it, and came to the field to test it.  I checked it and did a test and trim flight, and asked him about getting on the trainer cord.  He was confident enough from his sim practice, that he wanted to try it directly. He hovered without any issues, which is a testament to his sim training, but during landing, he brought the sticks down too fast, and slammed the heli to the ground causing some damage.  This is one area where many sims are more forgiving than real life.  He disappeared after that for a year, until this Friday.  Work and family had kept him busy for a whole year.  He was on the field again, and this time I checked the rebuilt heli and did two flights with him on the trainer cord, just to help him with the landing part.  But what was amazing was that he had spent the past 3 weeks on the sim (lots of hours), and in his second ever flight (the first one was only a hover of 2 minutes a year back), he was flying circuits and nose-in without any hesitation, taking the heli 200  feet away from him in all orientations.  Everyone at the field were applauding at this feat, and it is a great lesson in what difference a sim can do.  There was another person at the field who has been doing hovers and circuits for a few months, but has trouble with nose in even after 5 or 6 flights on a trainer cord with me; the difference is that he does not have a sim at all.

So my request to all beginners is... do yourself a favor... get a sim, and put in lots of hours on it until you are confident about handling many orientations effortlessly without thinking.

I understand anwar uncle, i do have a sim(RealFlight G4.5) and i practice on it. I have practised enough that now i can do torque rolls on the sim with light wind. As u say, i do need more practice. But the problem with the sim is that u can't practise hand launches, like throwing your plane and then quickly getting to the controls. If there is a way then plz suggest me. I have two other RTF's which i can fly with ease. But more importantly, i need to know about major physical changes to the plane to make it fly better.

@Rohit, from what I saw in the field yesterday... I think your model was tail heavy... so we need to adjust the CG. But, you should glide test the model again on a non-windy day... Similar to your model, my TUFFY is also made from high-density foam and when I glide tested it today, I could not draw specific conclusions due to strong winds... Lets wait for clearer weather :)

@Ashta, we really are having hard time finding fliers in Kolkata...

There are members here from Kolkatta who have mentioned their skill level as intermediate or above.  Try sending PMs to the following folks.

1.  Avishekghosh07 (http://www.rcindia.org/profile/?u=174)
2.  Rajib (http://www.rcindia.org/profile/?u=196)  (His flickr page shows interesting stuff like a field with many fliers and models : http://www.flickr.com/photos/27465921@N05/)
3.  joy4u (http://www.rcindia.org/profile/?u=207)
 

@ Sethji : Sure the C.G is an obvious problem, but now i also plan to increase the size of the tail wing. I feel that according to my begineer logic(though this may be completely senseless, expert opinion required) the front part is getting more lift than the bottom part of the plane. More importantly we need a calmer day. Regarding the photographs which are in the link posted by anwar uncle, the place seems to be the Race ground. I think we need to ask Rishi sir or Palash about their flying location. Just wondering what will happen after u leave, then again ill be alone.

well according to me there is nothing to do with lift with Horizontal stab(tail wing) especially with rc planes, it only decides stbilty to given weight and surface area, but you are right it plays important role too while flying, but not while launching! try to check CG again and as anwar bhai n asta ji advised seek experienced fliers help!
happy landing :thumbsup:
below thread may help a bit
http://www.simply-rc.com/Aerodynamics/04_Stability.htm

probably i could not convey what i wanted. When i say "throws", i meant the movement of control surfaces with respect to the stick. Pl keep them at low rates, that is about 30% thru Dual rate setting on your Xmitter. This is very very important. If the throws are more even an experienced pilot is sure to crash. pl check this.
ashta