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adhoc
08-06-2006, 07:06 PM
Wow. Over three months without a major crash, and then I have major crashes on both my Multiplex planes, one right after the other... (warning, this is somewhat rambling...)

Nice morning for flying, calm wind. I drive to my favorite park with my Easy Star and Twin Star II in the back of my car. I did exactly the same yesterday morning with no problems...

Lately there have been a couple of retired guys out there; they're trying to learn with those Yellow Bees, and I've been trying to help them get them flying. These planes work the same way Aero Hogs work, with just differential thrust on two motors, but the Yellow Bees sure are harder to fly than my Aero Ace bip and jet...

So one of the retirees is there this morning, and while he's seen me fly my Easy Star several times, he hasn't seen the Twin Star II, so I start with that one. Goes up great, flies around. There are also a couple kids and their dad, off to the side, but clearly enjoying watching the plane. Everything is fine, and I'm enjoying the TS2 more than ever, having finally trimmed it up right (the last 2 or 3 flights it has flown funny, and Sat morn I finally sorted it out.)

So I say to the retiree "Okay, here's the tricky part; landing it in this park..." (because the TS2 just floats along forever, so if you don't pay attention and plan your landing, you'll run out of room, even in a relatively good-sized park.) It is already coming over perpendicular to my landing run, so a little before I have to make my final turn, I pull off the power, and suddenly it rolls hard and spirals into the ground from 50' or so...

"What was THAT?!" I say. I walk over to it, trying to review what happened, decide if I did something to cause the crash. I wasn't doing much of anything, it was flying straight and level, and had plenty of speed. It didn't act like it hit anything; it just suddenly rolled over hard...

I get to the crash site, and on first glance it isn't as bad as I expected. The nose is a little crunched, and the foam halves split apart half an inch, but otherwise the fuse is intact; the wings are unmounted from the fuse, but intact; the tail section seems fine. One motor nacelle is completely broken off; I jump to the conclusion that somehow that failed and caused the crash, but on further inspection, I see that the left aileron hinge (thin foam actually) has ripped for several inches and the aileron is sticking way down. I don't recall seeing any hint of this before the flight, but it could have been a subtle crack or something... Anyway, that fits with the sudden hard roll and spiral into the ground; the motor probably broke on impact...

So while I'm not particularly happy about this, I put on a brave face and talk about how foam is easy to fix, etc. Which is true...

So we walk the TS2 back to my car, sip on coffee for a minute, and then take my Easy Star out for a spin. (This is my heavily-modded ES with 4" shorter wing and wingerons!)

Throw it up and it climbs away as usual, no problems, but about 2 minutes into the flight it suddenly rolls over and spirals into the ground, again from about 50'. "What the heck?!" I say, feeling like I'm having more than my share of bad luck in one day...

Walk over and inspect: the nose is compressed, nothing that can't be fixed using the "Elapor soup" method. The tail is broken completely off. And the servo arm on one of the wingerons has broken off near the center (where it screws in). We mull this over a bit, and I decide that it must have been the tail breaking off in the air that caused the crash, because I can't conceive of the servo arm plastic breaking like that just from lots of low level stresses (I think before that, it would have ripped the control wire out of the wing); it seems more like the result of the crash...

I'm less sure about the Easy Star failure mode, though... Can't think of why the tail would suddenly fail. The only thing I can think of is that since I've moved recently, for the first time I'm putting my planes in the back of my Acura Integra hatchback, and a few times flight surfaces might have gotten bumped or pushed, and maybe subtlely weakened...

Anyway, funny and sad to suddenly face my first major crashes on the same morning... Got some repair work to do...

I'll take some pictures and post them here, for whatever educational or entertainment value they may have... :o

firemanbill
08-06-2006, 07:39 PM
Sorry to hear that Andy! Any possibility you may have been shot down? Someone somewhere else in the park maybe?

If it's any consolation we went out again today after Church and had a great day. Only mishap was a bit of a rough landing with the funtana, tore one of the wheels off the gear strut. carbon ripped where the screws go through it.

My boy greased several landings on the esarter, we ran a couple of batteries through the mustang and the slowstick. Wind started to pick up so we packed it up and came on home.

adhoc
08-06-2006, 07:45 PM
Sorry to hear that Andy! Any possibility you may have been shot down? Someone somewhere else in the park maybe?Well, the thought did cross my mind, even though I'm flying with a DX6, so other flyers shouldn't have been an issue. And I was the only one flying, period...

I do wonder about other 2.4GHz appliances (cordless phones, baby monitors, etc.) which don't strictly comply with that band's licensing (they are supposed to listen for each other and choose a different frequency). If this was the case, there was absolutely no hint of any glitchiness or interference beforehand. I can't 100% rule it out, but I'm pretty skeptical...

Another reason I'm skeptical is that in both cases, the roll rate seemed to be faster than you would get, even with the controls hard over. That's why I'm inclined to suspect the flight surfaces failures as the cause -- seems to me that they would cause that kind of severe flight wackiness... especially the tail on the Easy Star; it was just hanging by the control wire, and would have been at a crazy angle to the wind flow...

BUT, I'll admit, I've never had to do this kind of post-crash analysis, so I could be wrong...

firemanbill
08-06-2006, 07:49 PM
It is odd though that both planes went out at the same time when the only thing in common really was the Tx... Hate to think it but maybe the Tx needs looking at. That's probably jumping to conclusions though...

adhoc
08-06-2006, 07:53 PM
It is odd though that both planes went out at the same time when the only thing in common really was the Tx... Hate to think it but maybe the Tx needs looking at. That's probably jumping to conclusions though...You can bet I'll be doing some comprehensive ground/range checking when I get my birds patched up! FYI, both crashes occurred relatively close to me (say, 100', maybe 150'), but at different places in the park...

firemanbill
08-06-2006, 08:01 PM
You can bet I'll be doing some comprehensive ground/range checking when I get my birds patched up! FYI, both crashes occurred relatively close to me (say, 100', maybe 150'), but at different places in the park...


Well that eliminates range and natural interference then doesn't it... Hmmm.... Interesting I'll be curious to see how it turns out.

frankieg125
08-06-2006, 09:03 PM
Any crash pictures?

adhoc
08-07-2006, 05:21 AM
Any crash pictures?I was planning to, but we've just moved and I can't find my camera, or much of anything else... you all know how it goes, chaos during and after a move...

As soon as I dig out my camera, I'll shoot some pix of the victims... I mean, patients... :rolleyes:

K CLOSE
08-08-2006, 05:14 AM
Don't feel to bad if you never really answer the "Why did it fall out of the sky?" question to your likeing. That sometimes is a problem in and of itself--as in "was that me or someting else?" Be glad you at least know it was not your error.

adhoc
08-12-2006, 05:49 PM
I just ruled out the transmitter. This morning I flew my Funny Park without a hitch.

Still looking for my camera...

On the Twin Star II, it looks like one of the motor shafts might be bent a little. Haven't tried putting the prop back on and running it, but I worry that even a little bend will make it wobble...

Today/tonight I'll cook up some Elapor soup! :D

adhoc
08-13-2006, 05:25 AM
Okay, finally found my freakin' camera. Here's the Twin Star II...

adhoc
08-13-2006, 05:45 AM
Here's the Easy Star...

adhoc
08-13-2006, 05:47 AM
Soaked the Easy Star's nose, and the broken engine nacelle of the Twin Star II, in very hot water, not quite boiling. Worked pretty well!!

adhoc
08-14-2006, 04:57 AM
Got my Easy Star back up in the air this morning, no problems.

Twin Star II is going to take longer...

But it feels good to get back up after such a one-two punch of crashes... :D

Solid Hit
08-15-2006, 11:45 AM
Got my Easy Star back up in the air this morning, no problems.

:D
Glad to hear it Andy. Gotta love Multiplex elapor. That could have done in a balsa or styofoam plane.

adhoc
08-15-2006, 03:57 PM
Gotta love Multiplex elapor. That could have done in a balsa or styofoam plane.You said it!

Sometimes I feel slightly "bad" for having a bias towards Multiplex products. I picked the GWS Funny Park for my third plane specifically to make myself "branch out" and try other products. But my Funny Park just isn't holding up like the Multiplex planes are; even just riding around in the back of my car, it keeps breaking pieces off the elevator and ailerons. There's no doubt in my mind that my Funny would have been destroyed by the same 50' crash...

Having the aileron hinge fail on the Twin Star II is a bit worrying. I'm going to do what I think I've read other folks do: just cut them off and mount them with real hinges.

I'm also going to strongly consider another Multiplex plane for my next (I'm about due). The problem is they don't exactly have a wide selection of models. The Magister doesn't excite me, although I've heard great things about it. I'm not ready for a jet yet. Don't have a big enough space (yet) to fly a full glider. The scale/cargo plane doesn't do anything for me. The new Acromaster is way over my head! That leaves the Space Scooter, which I've always thought looked goofy. But as I read about it, it sounds like it might be the right next plane for me...

adhoc
08-15-2006, 08:42 PM
I'm also going to strongly consider another Multiplex plane for my next (I'm about due). . . .That leaves the Space Scooter, which I've always thought looked goofy. But as I read about it, it sounds like it might be the right next plane for me...I've ordered a Space Scooter... Long live Multiplex and Elapor!! :D

aircruiser
08-16-2006, 06:40 AM
Sorry to hear that Andy! Any possibility you may have been shot down? Someone somewhere else in the park maybe?


That actually reminds me of these little kids that come out and watch some local guys fly and sometimes me. A few of them decided to throw rocks and see if they could knock the plane right out of the sky. :( Needless to say, one kid hit a freedom and it cracked the wing.

Sorry to hear about your misfortune Andy, hope everything goes well in the rebuild!

Good Luck!

-Grant!