Valley engineering Backyard Flyer UL

Hi guys,

There has been much discussion at the local UL hanger regarding this plane and it's possable problems mainly with the wing attachment and lack of supports. What do Y'all think of this plane? would you stick your butt in one?

My opinion,
The plane's wing attaches to the fuse with 5 bolts and has no support struts or wires, With this setup I bet that wing will flop like a wet noodle and possably break in turbulance. I would be willing to fly it once in dead calm conditions it it had a BRS equipped.

Chris

I am not a big fan of the welded aluminum frame. When you weld aluminum you weaken it. SO if its 6061 T6 it loses its streaten when heated.

As far as the wing. I dont see anything wrong with it. There are plenty of cantilever wing airplanes flying. Titan Tornades and Pipers are some example.

5 bolts that is plenty to hold the wing on. Chris a BRS will not do you any good at low altitude it something happened.

I think it all boils down to how well the center of the wing is built up. That is where the most stress/ load is.

I just cant see the wing as being verry strong, it is built like a quicksilver wing with tubes slid into pockets in the fabric and lacks true "ribs". It also has some funky triangular spar which is heavy and not very strong.
I agree with you that if they wish to use an aluminum fuse it should be bolted and not welded.

Chris

Is the wing spar one piece that goes from tip to tip? Or is it two wings held on the fuse by 5 bolts?
If it's one spar it would be better. If it's two separate wings that join together at the spar using 5 bolts then no way. Those wings would have too much leverage without some other type of support


It's not the nicest looking plane I've seen either

The wing is a one piece with a spar that goes from tip to tip, my main concern is the way it is attached. it has 5 bolts layed out like the 5 on a dice, the 4 outer bolts are removed and the wing is rotated for storage. Because the fuse is son narrow at the wing attach point I would be worried about the wing flexing at the mount and ripping off the plane not folding up as I may have alluded to earlier. the wing needs some kind of strut or wire bracing to keep it stable in flight.

Chris

Yes I agree.
The pendulum effect might be catastrophic on that joint.

I sent an email to valley reguarding this possable issue several days back and the response was that the bolts are "big" enough to prevent the pendelum effect I wonder how big the bolts are? If the bolts cant flex then the aluminum tube frame will right? A Midar Disentagration of the entire plane!! I think I will stay well away from this plane and would advise anyone else to do the same!!!

Chris

My friends Titan with 912 Rotax has four bolts that holds his wing on and hasn't come off yet.

In this case it's where the bolts are rather than the number.

The titan has a very sturdy frame and short wings this coupled with the wide fusalage at the wing attach points helps eliminate the "pendelum effect" which will eventually cause the welds at the wing attach points on the backyard flyer to fail or the aluminum tube to deform.

Chris

Chris wrote:

the "pendelum effect" which will eventually cause the welds at the wing attach points on the backyard flyer to fail

Did you get a really close look at it?

Quote :

would advise anyone else to do the same!!!

Now.. wait a minute... have you had a chance to sit down and talk with the designer about this? It seems a lil unfair, maybe premature, to criticise this like this unless there are failures known, or at least signs of incipient failure. It sure seems to fly well anyway. It just seems like you aren't quite close enough to the project to say all of this.

Did you buy your LE from them? How do you like it? In my search for the 'plane of my dreams' this one keeps popping up. I just read you SPECS of it at your site. I couldn't get a pic of it to come up there. This is my 1st visit here to this forum, haven't had a chance to check out the gallery for a pic.

Now... I hope this doesn't come out wrong... but I have a serious question. I don't doubt your honesty, or any LE owner.. but just to reassure me, do you *really* come in under 255 lbs, with hydraulic brakes, electric start, battery and custom exhaust pipe? I am really attracted to this design but... I *really* wanna be legal.

Isn't that 'Big Twin' about the loudest engine you have heard? All's I have to go by is sound from various videos and I really can't tell from them but it seems to have a real bark to it. Do you have enough weight-margin left to maybe add a muffler? Well, not you exactly, but will *I* if I go this route? Quiet is good.

Is this Honcho wing one of those that those four fellas had, that re-engineered theirs in order to copy it for each of their LE's? Can't remember their names. Think originally they were planning to use A2042 genset engines? If I build a LE, but use the LE wing design, what kinda performance differences do you think I will encounter? I guess I am asking why folks wanna use a different wing.

Thanks
GeoB

So, it was nearly 4 years since this particular controversy. Do we know anyone who's got one of those? How many hours and landing cycles is on it?

In these 4 years, Valley Eng guys came up with a trike version, which I'm considering.