Hooked-On-RC

My Feedback: (16)

T BOB,
It is interesting you post that picture of the Planes Plus Extra 330L. That plane is the reason for this post to begin with. I used to have that plane, it survived seven 10 minutes flights and on the 8th flight the wing snapped off in mid flight and down she came. I dont think strength was the issue more so piss poor quality of building is what caused the crash. I am guessing that some of the covering lifted a bit (after being ironed down three times) and then ripped open the leading edge sheeting which caused air to get inside the wing and that was all it took to completely destroy the wing.

When we looked at the wing half that snapped off there was very little (or none at all) glue holding the wing ribs to the leading edge sheeting and very little glue holding the wing ribs to the the spar. Interesting enough the wing tube held firm in the fuse and all the support structure around the wing tube just broke away. So all that being said I was thinking if there was some short cuts taken in the way the wing was designed to save weight and in this case the short cut they took was the use of GLUE. Of course now Planes Plus is out of business, Carla and crew are no where to be found, no one will divulge who the factory in China was that built their planes, although I did hear it was the same factory that made planes for Chip Hyde and I heard they are out of business too. So I have no recourse to get any replacement plane although I am not sure I want one.

Since then I have purchased an ARC from Aeroworks of their Extra 260 QB version and I will tell you this plane is really well built, parts are tight, square and glued very well. I have actually had to fill in some lightening holes so I have places to put some switches, but this plane is a really well built. Covering it took some work and I still have to cover the fuse but it is sure nice to have access to all sides of the fuse when you are running elevator leads and rudder pull pull cables. Would I buy another ARF, I don't think so, Buying an ARC gives me a chance to see it "in the bones" and make any necessary additions before it is covered. Also get to choose my own design so there is not 4 or 5 of them at your flying club.

I just hope anyone flying one of those Planes Plus Extra's does so with caution...it may have an expiry date on all the glue joints, if there is any glue at all!
Cheers,
Hooked.

andy86na

My Feedback: (3)

Think about strength this way Strength==(Strengths to weight ratio)*weight. Conceptually, in designing a plane you try to maximize the ratio above. The higher the ratio, the better the design because you achieved the same strength with less weight. Conversely, poor designs will be too heavy for a given strength.

So to answer your questions directly, any design changes that lead to increase in strengths to weight ratio (e.g. using better materials like CF or optimizing re-inforcement / lighting holes distribution, etc.) will not sacrifice strength for weight. If all you do is remove material without 'intelligent' design changes it can be viewed as sacrifice.

aerolou

My Feedback: (3)

Everything has it's design limitations. It is up to you to decide what the limitations are and whether to exceed them or not.

Lou

T. Bob

My Feedback: (9)

I have seen 2 Planes Plus wings exploded in flight.
I agree the wings are built poorly and it's a shame because the planes fly really well.

fisher1648

There is a big difference between "well engineered" and "well built".

Seems to me most of the problems associated with structural integrity occurs due to inadequate glueing at the factory. I'm not too sure the folks overseas assembling these big ARFs are trained very well regarding where to focus on "getting the glue". After seeing some of the glue joints (or lack thereof) I always wonder. Often times it's not "if" but "when" will it come apart.

I beleive the airframes are nicely engineered but then they have to be assembled by someone. I've never visited an ARF plant but my guess is there arent many structural engineers working the glue-guns.....more like a 13-yr old who is blind in one eye from a laser-cutter accident making $1 a day. Who knows what lies beneth the covering ? You normally never find out until it's in a heap on the ground. But, that's the trade-off to convienience and price these days.

I keep my fingers crossed that it holds together everytime I fly an ARF. Kind of makes it exciting in a way [X(]

Eric

Gumby2!

I vote No! Planes are built to fly, not crash!