bigchap

i experienced my first flutter incident today,i've been flying for 7 years so it came as a bit of a shock!i re-propped my nemesis to get some more speed and this is the result,it was flat out at an estimated 80 mph when i saw bits fly off,i cut the motor and the model came down horizontally just like a dethermalised free flighter,an easy fix but i think i'll get the glass and cloth out to make it stronger before i try again.

bbbair

I Don't know if that was 'Flutter' or 'Structural Failure'.

Making any AC go faster than design specifications will cause 'Problems', from your photograph your plane seems to be a Foamy - no problems - but there are definate limits to this type of plane.

IF you wish to fly at 80 mph - you will have to buy/build a plane that can withstand the stresses envolved.

That being said; the fact that you were able to land that plane is quite the feat!

Well Done!

bigchap

all i did was go up on prop pitch,i am using the recommended motor and lipo but this model is obviously close to the edge with the recommended prop and i overstepped the mark,thanks for the compliment on the landing but i didn't land it!i cut the power,it scrubbed off speed real quick and just hovered in horizontally,no other damage at all.i heard a flutter type sound just before this happened but structural failure could be the cause,i don't suppose it matters much as the airframe was dirt cheap!

jetmech05

It does matter because flutter is caused by something coming loose or too much gap at a control surface hingeline...the end result is structural failure..
if you didn't hear a buzzing sound before pieces flew off then strengthening the airplane will be ok...
However if it was caused by flutter (heard a buzz) then you need to find out if a servo is weak or you have play in a push rod, control horn or, control surface. plus seal the gaps in the hingelines or it could happen again even after strengthing the airframe

bigchap

i do understand the causes and know how to remedy them,i just think i pushed this little aircraft too far.

cutaway

Glass will be heavy. I'd try tissue paper stuck down with well thinned white glue first. You'll be amazed how a bit of tissue that weighs almost nothing can stiffen something up.

FlyerInOKC

My Feedback: (6)

Try clear packing tape in the control surface joints to seal the gap. It only needs to be on one side and cut properly you can't see it.

Mike

bigchap

fixed it today,stiffened it up using balsa on leading edge of horizontal stab and carbon rod in elevator and fin.i'll find out how it holds up at the weekend.if it's good i'll paint it because it looks awful at the moment.

FlyerInOKC

My Feedback: (6)

I forgot to mention I have several foam planes one a DHC-2 from GWS and they use a bamboo stick to reinforce the elevator and for the wing struts. I broke a strut (hanger rash) and found bamboo skewers for making shekabob were the correct size. You can find them in 10" and 12" lengths.