Aviation models Yak 54 33% maiden and death

[Jamieman]

Be tapin mine in right now.
Havent heard of it before tho.

[MacDaddy]

Hey all, there is a growing trend toward gas at our field too, with it comes new responsibilities. At our recent big bird fun fly, an experienced gas pilot pointed out that big singles (a DA50 in this case) vibrate....then he pointed out that the crystal is a very important part and you don't want it to come out. I thought to myself, I can barley get that sucker out... but it's going to vibrate out?? Then I thought of how much time it takes to put a piece of packing tape around the rx... 60 seconds....nuf' said.

BTW, I recently set out to maiden my Funtana w/ a YS 140, did the range check and the surfaces flipped out..... I then quickly remembered that the antena was wrapped up nicely, just as it was shipped from Futaba with the little foil tie wrap still in place.....whewww.

With that said, how about everone take 10 minutes per plane and double check all the little things, linkages, connections, hinges, bolts, nuts....the werks .

Hate to see them go in on maiden......sorry for the loss . If it's worth anything, at least you figured it out....not knowing is worse...

Mac

[Pharriesk]

Sorry for the loss man.

I got that problem like 3 days ago to with my new Extra with DA 50-R.
I was flying nicely but sudenly the plane woudn't do anything, so it flied in cirkels above, at 350m i guess the engine was out of fuel so it crashed in a tree, only a big hole in the wing.

My crystal popped out maybe at your plane to?

[karlwatt]

I am very sorry for your loss, I think I would puke too!!

Wow, I am actually surprised at all the responses of people having crystals popping out. I have never had this happen or heard of it. Maybe because I was taught from day one to protect the receiver from vibration by wrapping it in foam all the way around. Thus the crystal is also held in place, and protected to some degree, by the foam. If vibration is the enemy then just taping in the crystal is not enough, insulate the receiver too.

[Wuertzer]

Hum, I have been flying for 12 years and I haven't never heard of this either. But I too have always wrapped my receiver (and battery) in foam, which more than likely helps hold in the crystal. But as a retired Air Force electronics tech, I have to wonder if on these big gas birds (I’m building my first one now) if there is enough vibration being passed to the receiver to cause the crystal to vibrate out, then I would have to seriously question the effectiveness of the mounting of the receiver in the first place. There is no way that much vibration can be doing the electronics in the receiver any good and I can’t help but believe it’s also effecting the lifespan of the receiver as well.

And in this case, taping the crystal actually seems like a band-aid for the real problem (no pun intended!!) Seems what really needs to happen is a reassessment of the mounting of the entire receiver to isolate it from the vibration. I have seen some of the TOC types mount the receiver on a board in foam and then suspend the board from the fuse with rubber bands so it is held in a cradle. Something to think about in future builds…. Or perhaps vibration isolators on the engine mount to cut down on the vibration transferred to the airframe from the source??? Again, all that vibration can’t be doing servos, receiver, EI box or even the airframe itself any good……

I too am sorry about your loss, but I thank you for sharing your experience, not only you, but many others will learn from your experience and both our futures planes will be the better for it.

[romanrc]

This is owr Hobbie expension and hi risk

[Mark Davis]

Sorry for your loss man... It sucks to lose an airplane... It's worse when it's on the maiden...

I've been taping my crystals in since Wayne lost his EF Yak last year due to the same issue...

Lessons Learned are not always easy...

[clivehodder]

Uh! I seem to be missing something guys!! If you have $3000+ Invested wouldn't you use a synthesed Rx???? DUh!

[SUPERFLYJAY]

HE WANTS TO SOFT MOUNT A DA50? OR BETTER YET A 150 NOT A GOOD IDEA IN MY OPINION.

[Throttlestick]

	Quote: Originally Posted by clivehodder
	Uh! I seem to be missing something guys!! If you have $3000+ Invested wouldn't you use a synthesed Rx???? DUh!

Boy , you have it all figured out huh?

[BR289]

A guy in our club rebuilt a beautiful Byron Gee-Bee. It was flying great for about 6 minutes or so when the guy test-flying the plane decided to try and land...as he was about to make his downwind turn, the plane suddenly rolled over and smashed into the ground at about a 60 degree angle and blew it apart!
He said he always has another person check out his stuff before it flies but neglected to do it this time....The reason for going in? His battery wires were not secure and melted against the muffler or another part of the engine, and it shorted out!
If possible, always have a freind check over your work just in case you may have missed something...

[Highlights]

	Quote: Originally Posted by clivehodder
	Uh! I seem to be missing something guys!! If you have $3000+ Invested wouldn't you use a synthesed Rx???? DUh!

Explain............................

Thanks