I had my duraplane out last night and when I made a steep dive the plane did a quick loop at the bottom and headed into the ground about 6" deep. For it to turn such a quick loop I am thinking the wing lifted off the fuselage thus changing the angle of attack of the wing. Has anyone had this happen to them or seen it happen?

I had this happen to me a long time ago. Actually it looked pretty funny, like something you'd see in a slapstick movie. It happened coming out of a split-s and you could actually see the wing stretch the rubber bands and pull the fuselage up to it. I was lucky and landed immediately. I learned my lesson.

It will make you think your radio is haveing problems, It will some time give opposite control and make you think you got shot down. When you think uou have anough rubber bands add a couple more and use a good grade of bands!

How many and what kind of RubberBands were you using?

I always use at least 12 rubberbands, and usually 14. I make sure that the ones I re-use are still good and try to have at least 2-4 brand new ones each time I setup.

I store the used ones in a plastic box (my old glo-igniter box) with Baby Powder. The powder helps absorb the oil and makes the bands last a little longer.

It's a bummer to lose a whole bird just because of skimping on how many bands you use. Like Outlaw says, use enough to do the job, then add several more!

In the manual I got with my airplane it said to use 1 rubber band for every 1/2 lb of weight, thereforth 12 or so for a 40 sized trainer. If you want cheap but good rubberbands, go to officemax. Get 1 lb for $2 or so.

those arent fule prof... use the right kind.

I use # 64, but I never use the same ones twice either. I get the two pound bag from Office Max too. For a couple bucks they are one-time use and I just cut them off when I am done. I used 14 on my overweight Hobbistar .60 with a .72 engine. I flew the elevator off of it before the rubber bands ever thought about giving up. I used Five on each wing side and four cris-crossed. I also have litte epoxy boogers hanging down on the end of my dowel rods so none of them can ever slip off. I just mixed some epoxy and let it form a small drip on the end of the rod. It may or may not help. but for the 30 cents of epoxy and the 2 minutes it takes to do it, it seemed well worth it for a little extra piece of mind...

Just a thought... Some only use the "exact right thing" and I can't blame them.

Yeah they aren't fuel proof, but half the price. Just throw them away or shoot people at school with them. If you want, put cornmeal, baking soda or some other oil catching substance in the bag and mix it with them.

id stil lrather pay a buck more and no that i dont have to wory about fule eating through the rubberbands, id hate to lose a plane over somthing so menial like that.

Skip the rubber bands all together!!! Convert that bird to bolt on wing!!!

not worth it on a little trainer but on bigger planes... you will not see a rubber band near it. im very causious with my planes.

Wing bolts are better, quicker, and safter in my opinion. I will probably build all my future planes with wing bolts.

However, rubber bands on my old trainer are worth converting.

i riped a bracket out doing them up to tight, if tis arf put some glue around it to toughen it up.

I always rob the mailman :P The mail is bundled here with excelent rubber-bands, so i ask him every now and then

The club I fly at has a lot of people in it with more flight time then I do.. All of them swear you should never cross the rubber bands.. Anyone heard of this? Why? I have always been taught to cross them adds more support in my mind... They say something about when you crash it is harder for the crossed rubber bands to come off.. I say hell with that.. If you crash and you have the right about of rubber bands there will be damage of some sort and it has nothing to do with crossing them.. IMHO

Crossing them keeps them from coming off during flight, or at least that is the idea. I would cross them, if you crash, you have bigger problems then rubberbands.

Wing bolts are way too easy to install to risk rubber bands on any plane. Takes less than 1 hour to install the "canopy hook" on the leading edge of the wing, and the bolts aft. I use 1/4" 20 nylon bolts and either thread the trailing edges "cradle" or drill it and use those little compression fastner thingys. I also beef up the trailing edge with 1/8" plywood where the screws go through the wing.

It really does look funny when the wing does that.

Real windy day, got the plane right up there, and I mean way up there on the windward side of the field, brought it down in a shallow dive at full power right past the strip.

At about 20 feet of the ground and wings level it went into a full loop. the plane was really moving too. You could see the gap between the wing and the fuse. Everyone at the field thought I had balls to try that, but I dint even give it up elevator. The front of the wing caught a slight gust, lifting it slightly and then as I was moving so quick it caused the wing to angle more up, causing the bands to stretch more, causing the wing to angle up more. It only stopped looping after two full loops when the speed got below a point that would let the wing settle back down.

No damage at all to either the wing or the fuse, just added ten years to my life watching it and waiting for the wing to fold.

Now I only use new bands every flight.

Cheaper than replacing the entire plane.

Rubber bands on a wing are the only way to go on a trainer. I have seen many trainers cartwheel on take off, and it's not a big deal--unless they are bolted on. Then, not only do you have to "re-do" that one hour it took to convert them, you have to do some major repair to the center of the wing and probably the fuse.

Thor,
I had it happen to me, but with much worse results. I generally flew with 8 rubber bands. I read an article about "How to fly in the Wind", since I live in a windy state, it was often said at the field, "If you can't fly in the wind, you can't fly too much here." So I was determined. Read the article three times, and just waited for the first 25 mph+ day to try out my new "skills". I remembered everything in the article EXCEPT the paragraph at the very beginning of the instruction that said "Always use extra rubber bands." I taxied out, with the elevator down, ailerons down correctly, swapped them in the turn, and off it flew. It was doing great, I was really getting the hang of it. Brought it in for a landing, touched down, ready on the controls, took off, and then really got brave and started doing manuevers upwind and downwind. The wind kept getting stronger and stronger, and was probably 30+ with gusts around 45mph (strong enough to rock me on my feet). As my confidence built I got more daring, and as I did a full speed pass down wind, I suddenly got curious as to how quickly it would slow down if I did a 180º turn back into the wind. I yanked the wings over at 90º, pulled all the way back on the elevator, and leveled it out. It nearly came to a stop, and I saw (what I eventuallyl found to be the plastic left wing tip) fly off the airplane. As I was trying to figure out what it really was, my first thought was it had ripped the covering off, the plane suddenly nosed down about 45º and headed for the ground. I was so dumb-founded that I never did pull back on the throttle, but almost ripped the elevator stick out of the radio. In a matter of seconds it disappeared behind the trees. When I found it 10 minutes later, it was literally stuck in the ground with what was left of the tail sticking in the air. The impact was so hard, that it had pulled the tail-feathers loose from the fuselage, and all three were bent forward. The engine and about 3" of the nose were imbedded in the ground. Fortunately, it had rained the day before, and other than a crushed spinner and prop, the only other damage was a crack in the case around the carb. When I finally looked at the wing, there was one tip that needed two ribs and the balsa sheeting replace and the covering. It was in amazingly good shape. All the little pieces fit in my jacket pocket. What the post mortum revealed was that not only had the wing been lifted up, but moved back until the control rods stuck into the fuse about an inch behind the wing seat. That had changed the DG, eliminated any possibility of control. Pretty weird in my opinion.

The moral is, rubber bands aren't bad, just use plenty of them. The one for every ½ lb sounds pretty good--unless it is windy! :-). I hope someone else learns from my mistake.

I don't think it was your bands unless I misunderstood your message. If it lifted in the front (most likely) then the loop would have tightened. If it lifted in the back (hard to do from what I understand) then the loop would have lessened pushing the tail down or back.

Anyway, good rule of thumb I have been told by several people is:

After 3 or 4 flights, replace your bands if you are pulling speed ...doing loops or placing any type of stress like this on the wing.
NEVER reuse rubberbands..Ever!

Good luck. This message has prompted me to make sure my bands are fuelproof. I replace after 3 flights mostly because after my 3rd flight one day I was doing a preflight inspection. NOticed one motor screw almost completely out. And also noticed one rubberband off the dowels dangling because it snapped. Makes ya think.

S

I get the feeling from what I saw (remember it was doing "light speed" when it went past), that the front lifted a little, causing the start of the uncommanded loop, and as the nose came up, the angle got steeper, the wing lifted more. and so on until the speed dropped enough for the wing to settle down again. there was a distinct gap between to wing and the fuse.

I would have been doing over 100 Kmh easy. The loop was no more than 5 meters in diameter, thats 15 feet.

1 and a half loops later it stopped. I couldn't have done anything about it as i was completly gob smacked. Just watching and waiting for the wing to fold.

I have to give it to the manufacturer, that wing took it, and is still flying today.

Techone.

Rubber bands on a trainer are a good idea; re: cartwheels - been there, done that. I figure that wing bolts would have greatly increased my down time. The thing is, the way the trainer is designed the wing sits precariously but firmly into a shallow fuselage indent on the trailing edge. During a hard landing, the rubber bands allow just enough give for the trailing edge to lift over the fuselage - popping the wing and in most cases doing little damage. Wing bolts defeat this design feature, eh? Stay with the rubber bands - even if it identifies you at the field as a wanna-be!

Common sense says rubber bands are cheaper than airplanes.
Never, never reuse them. Cut them off the model when you're
thru for the day so you're not tempted to reuse.
I had a flying buddy that lost two planes back to back because
he reused rubber bands, I finally took away his container of
talc powder and used rubber bands and gave him a box of
new ones. Sad thing was, he owned a hobby shop with a
plentiful supply of rubber bands, go figure.

I agree, not worth it on a trainer and you're right, it is better to always use the recommended items. But like I said, I only use them once since they are so cheap. I even soaked one in fuel for about an hour and it didn't seem to do much if any damage. As for not having bands on big planes I did see one that did - sorta. They may all be like this or it may have been just this one. We have a guy that flys a Giant Stinger with a two piece wing. It has the support bar that runs through the fuse into the wings but he holds them together horizontally (attached to the fuse) with the 10 bands looped on a hook. They're the same ones we get at Office Max. He might be tempting fate but he said no problems in 16 months.

Just a thought... I can't blame nor would I harrass anyone for using the best stuff available.

Rick