DVI

I was hovering my Blade 400 at about six feet high in a very stable hover when all of a sudden the helicopter made this terrible noise
and fell stright to the ground! I was totally stunned. I will need to replace the tail boom, rotor blades, main shaft, feathering shaft, tail fins, canopy, blade grips, and a servo. I have been flying this helicopter for weeks now with no problems. If I had crashed due to dumb thumbs, I would feel alot better about the crash. But I have no idea what let go, for this to happen? The crash broke so much stuff and several linkages came off during the crash I cant put togeather the cause.
Has anyone had this happen to you?

Fly To Chill

My Feedback: (20)

WELCOME TO THE WORLD OF RC HELIS

SeaComms

When you say fell straight to the ground with a horrible noise - what exactly did it do? Have heard a few reports of the sticker peeling off the motor mid flight and popping off the elevator linkage.

What sort of noise was it? When it fell, did it lurch in any direction, shake violently, or keep level and drop like a stone?

I agree it would be nice to know what happened so you can try and avoid it in the future.

DVI

SeaComms
The noise was like the blades tearing up the air, and the helicopter fell stright down very fast!
One thing for sure that I have learned from this, Is that I will not hover the helicopter closer than 6 to 8 feet from myself or anyone else. The event happened so fast I had no time to react.

Fly To Chill

My Feedback: (20)

I was flying my belt cp the other day doing some ff flight stop to do a little side hover all of a sudden woof,woof,woof the heli started to lose lift hit the th.hold about a foot from the ground landed ,check it out and what do i see one of my links unscrewed itself a little loctite and off and away no broken parts onther then a nick in my main gear. the more you fly everything starts to slow down if that would of happen a month ago I would of crashed.

Coyote64

If it just lost power and returned to terra firma then i would say it was probably a radio signal loss and the default settings are to go to 0 throttle hense sudden drop.

But as there is a noise present then electrics other than motors dont really make a noise when they fail they just fail, well maybe a bit of smoke

I would think that for it to plummet without any main gear stripping would point me towards the pitch controls, if a linkage came loose then your pitch would go negative, or at least one of the blades would and then that might explain the cutting sound as one of the rotors would be at differentpitch than the other

SeaComms

Yep, that sounds to me about right too - I would say you probably lost a link to one of the blade grips. Anything else popping off would have thrown you off at an angle I would suspect.

DVI

Ok Guys
I will definitely check those linkages before each flight now!

jp473

Did you ever determine just what caused it? Or is it still a mystery?

DVI

jp473

Still do not know for sure.
I will replace all the bent and broken parts, and give it another go!

DVI

During the tear down of the helicopter, I did find that the swashplate was stiff to rotate and felt like it had notches in it. The large bearing in it is bad which may have caused the crash. Maybe that could have caused a linkage to pop off. This helicopter has about 30 flights on it and I have kept the machine clean and have been using a dry lubricant, (Silicone Spray). I have not lubricated the big outter bearing of the swashplate the one that has gone bad. Does anyone know if that bearing should be lubricated, And if so using what lubricant?

DVI

Helicopter back togeather, As I was test hovering only inches above the ground it did it again. The blades made a loud whoosh sound and my reaction was to pull power off. No damage to the helicopter. I then put sand bags on the skids and powered up helicopter again and at about 3/4 throttle the foward servo starts pulsating back and forth, moving about 1/4" from center in both directions. I have replaced the servo and the helicopter fly's fine now. I think that was what caused the crash in the first place. Maybe the swash plate was damaged in the crash.

casey_lamm

bad servo then? Seems to be pretty common with these things. I am going to order a set and replace them all around as soon as I get my dx6i sold. Now on ebay.

Coyote64

Get em changed over for some hitec hg 65`s [)]

DVI

Is the hitec 65 good for the tail rotor control also?

jp473

God idea!
Lock er down, power er up, put er under a lode and observe the reaction.
I like it!
Thanks