PAU 43% Edge 540 Build

[cbk07]

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[Islandflyer]

Following a wing failure yesterday (Saturday), we at PAU have decided to recall the wings of the 43% Edge 540 ARF, and a few customers were already notified by telephone. This costly decision was made as proactive measure in response to one single incident that happened on one of our demo plane.

Just to put thing into perspective:
-Ken’s demo plane has more than one hundred flights with no incident, and is still going strong.
-Dave’s demo plane had this problem in its eleventh flight. Upon close inspection, the glue is what failed, rather than a lack of glue as we first feared.

Unfortunately, this demo plane (#2) was not set up as prescribed with 3 aileron servos per side and 2 elevator servos per side. Instead, it was set up with 2 aileron servos per side, and 1 elevator servo per side. Therefore we will never know if the failure was inherent to the construction, or due to the number anchor points on the ailerons that was reduced to 2 per side.
Indeed, we at PAU at well aware that the torque of today’s Ultra Torque servos can move the large ailerons. However, the question is the flex in the ailerons this size: if only 2 servos are used, there could be enough flex to allow some flutter. This is a possible reason for glue failure in wings, as even 1 second of un-noticed flutter is enough to rattle wing components loose. Once some components have come unglued, the integrity of the whole wing is jeopardized.

In any case, even tough we unfortunately will never know the definitive answer as to the cause of the failure, PAU is contacting the customers who bought the 43% Edge 540 ARF to notify them of the decision to recall the wings. We are working on a plan that will allow the speediest replacement of the wings: one likely solution is going to be a replacement of the built up wings with foam core wings. We are looking at the possibilities of manufacturing these foam core wings in the US, in spite of the high costs involved, in order to best serve our customers with the shortest possible delays.

We apologize to our customers for the inconvenience. This failure happened yesterday, and today we are already hard at work to find the best solution. We also urge every one to follow our recommendations: DO use high 3 high quality servos per wing, and 2 high quality servos per elevator.

The best place to keep posted on this issue is indeed in the PAU support forum.

Several of the 36% Edge has been flown very hard for the past several weeks, and has had no issue: hard walls, blenders and parachutes.

[macanaw]

Here is the skinny on the wing failure.

Saturday the 23rd at the St. George annual fly-in, my 43% Edge did suffer a wing failure. It's important to note that this plane is the first "production prototype". There are currently 2 prototypes, one has over 100 flights on it and continues to great. My plane was on it's 11th flight and had been put through most maneuvers you can imagine and it flew them fantastically.

After the noon demos I was taking another flight for some IMAC practice and to let Eric Powell give it a try, I was in the process of preforming a 1 1/2 positive snap when the wing failed, I rolled to knife edge and flew it back around to the runway and set it down but broke the lading gear in the process. I know of at least one person who has video and I expect it to appear soon. Even with one wing the plane was really easy to fly

I talked to PAU that night and they are being very proactive in their response. They are going to recall and replace all the wings. Even though this appears to be an isolated incident, they do not believe in taking any chances. They want every plane to be 100% and every customer to be happy with their purchase. I can't tell you how impressed and how glad I am to be with PAU. Herve and Ken have at every turn gone above and beyond what I would normally expect from even the best manufacturers.

If you have a 36% Edge don't fret about your wings, they are fine. This is something specific to the 43% Edge prototype I have; Ken and Herve have already jumped into action to ensure there is no chance of this happening to someone else.

At this point all I can say is, don't for a second let this incident detour you from getting one of these planes. THEY FLY AWESOME!!!!! I will have mine in the air again soon and coming to a flying field near you .

David Fox

[macanaw]

Jinx you owe me a coke

[madmax]

Heya guys, I'm moving this thread into Giant Scale Git r dun for visibility. I've been hearing a ton about these threads, but didn't know they were in here!! Awesome work guys, thanks!!

[Islandflyer]

Update on the new wings for the 43%:

I have just received confirmation from the factory that the new wings for the 43% are scheduled to ship on March 27.
We will ship them out to our customers as soon as we receive them.

[macanaw]

SWEEEEEEET.

That Edge is an awesome flying plane, I can't wait to get back in the air

[xtreem3d]

it's too bad you had to go through this aggravation..... thanks for the update and thanks for shipping my plane out w/ out having to wait for wings,
steve

[xtreem3d]

do any of you know if the standard , not compact, DA mufflers will fit inside the cowl w/out having to cut the front up,
steve

[macanaw]

I don't know off the top of my head but if you need to know before placing an order, I will grab some from a buddy of mine and check it out.

David

[xtreem3d]

thank you for offering, turns out i'll be cutting my cowl today using a borrowwed da150 & standard mufflers so i'll know as soon as motor is on...before i order my mufflers............just hoping to get everything done so when wings show up that's all i need to do,
steve

[macanaw]

Are you running 2 elevator servos per side? The plane is much easier to balance if you are.

David

[xtreem3d]

as of today i am not. i have 2 8711's , one in each stab. i have a seiko as far back as i can get it and have my batteries at about the back of the canopy. FWIW the stock mufflers DO fit in the cowl w/ out any cutting . i didn't follow the thread so maybe this was covered but on my firewall it IS necesary(sp) to cut back the bottom and right side (from in the cockpit) to allow clearance for the fins of the cylinder and the back of the mufflers,
steve

[Islandflyer]

As a company, PAU does recommend using 2 elevator servos per side, and 3 aileron servos per side.
PAU will not take any responsibility for any wing failure or elevator/stab failures (ad their consequences) when using less than the recommended number of servos.
As we have state before, there is no doubt that some of the super-high torque servos can move the surfaces. However the mere size of the elevators and ailerons can cause problems in these surfaces when the number of anchor points is reduced.
Any one deciding to use less than the recommended number of servos must understand that hey are taking full responsibility for the possible consequences of such choice.

[xtreem3d]

herve,
i understand and that's why in my post i stated "as of today" , i'm probably going to add the second set of servo's the more i think about it,
steve
p.s. is everything still on schedule for the wings to start shipping next week?