My C-310 takes off by itself ! Why?

[dahawk]

Yikes ! Need a little Forensic Pathology here.

This plane is so good it takes off on it's own ! Just being facetious

Wow, a new first for me. Was at the field with several planes the other day. Had 4 good flights with the GC C-30. Flew beautifully. 10 mph wind. Hardly a twitch. Also had a few edf's and my old Airfield Cessna 182 with me.

All was going well. Everthing trimmed-out nicely. Then, a near disaster.

Had brought the 310 down on its last sortie of the day and taxied uneventfully to the hangar area. A happy camper so far.

Had her turned paralell to the field, heading 090. Then, switched models over to the C-182 on the Futaba 6EX. All good so far. Control surface checks. good. Taxi to runway. Take off roll, rotate... all good. Smooth as silk.

But in the corner of my eye I see something moving from behind me fast and hear the motor(s) revving. My buddy yells: " Hey !" " Bring your Cessna down now". I make a quick 180 back to the runway and landed immediately.

Low and behold my 310 had rolled and got airborne on it's very own.

Then crashed about 100 yards down the field. Holy $%^t, Batman! The guys said it rolled perfectly true and straight and lifted off briefly.

Luckily not much damage at all but could have been a very dangerous event. The cowl on one of the motors came off with the motor wires to the esc disconnected. Windscreen came off. Nose gear bent slightly. One of the mains slightly dislodged. No foam damage at all. Didn't even break a prop.

Checked my Futaba TX. Yes, correct model was in play. The one thing I did not do in haste to get-in another flight in was to disconnect the lipo from the 310. Dummy me. But still. Should this be able to happen? An rx is bound to a tx. End of story. I'm still perplexed. Note to self: Never leave a plane sitting there with a lipo still plugged in! Close call.

Been at this solid for two years now and have never experienced an event like this or witnessed anything like it.


Now that I can laugh it off, I am even more impressed with this plane. Auto take off though?

Ah, lessons learned... on the lipo removal post flight.

But how could it happen? Two seperate Futaba Fasst rx's bound to tx. Could it be that Futaba model memory does not neccessarily mean model match like the Spektrums ?

-Hawk

[Fishbonez]

Shaweet Hawk that plane loves flying so much it cant say no and becomes as jealouse when flyijng others.

I am guessing here but maybe a short to power at the motor causing voltage to the motors.
Just guessing sounded like an interesting day to say the least

[dahawk]

Thanks Fish,

Not really sure. Very wierd. Hey, are you back amongst the flying?

[aerocal]

Futaba does not have a "Model Match" type feature.It does not care which model is selected in the Tx or how many are powered up.Your incident sounds a little more dangerous but not quite as exciting as taking off with the controls reversed because you have the wrong model set in the Tx.
Glad noone was hurt.Lesson learned.

[xmech2k]

Stupid question here: So you're leaving the batteries plugged in on your planes when not flying them?!? Or did I miss the part of the story that said 'I pulled a bone-head move and forgot to...'?

[dahawk]

Originally Posted by xmech2k

Stupid question here: So you're leaving the batteries plugged in on your planes when not flying them?!? Or did I miss the part of the story that said 'I pulled a bone-head move and forgot to...'?

X,

LOL - By habit, I always disconnect the lipo after each flight. The C-310 compartment is located in the belly which means turning her over to remove. As a, yes, bone-headed oversight, and being distracted, I was in a hurry to get the C-182 up and just left the C-310 locked and loaded. At least I parked her paralell to the hangar and runway.

[Fishbonez]

Originally Posted by dahawk

Thanks Fish,

Not really sure. Very weird. Hey, are you back among the flying?

Not yet but soon

[xmech2k]

OK dahawk, I thought you've been in this too long to make that a habit! Well, live & learn...

Bonez, I forgot you were out! Looking fwd to the saga of your SC's again!

[Fishbonez]

Thanks XM cant wait myself getting worried I will not remember how to fly.

Hawk it sounds like someone mentioned futaba does not have model match...I still wonder about a wire sending voltage to the wrong place, Just seems to odd. I have mistakenly forgotten to pull a battery out before and boy was it dead by the time to fly the next day but I cant see that being the reason for taking off. Just does not seem logical to me I do tend to over think sometimes

[rcers]

Correct no Model Match. This would have been avoided with Spektrum - a rock star feature they have.

However, I remember something else. I did the review on the Futaba 6EX and they had SERIOUS issues when they released the 6EX with a batch of transmitters having a GUID code (supposed to be unique) that was all zeros. This caused the issue of shoot downs since your TX could control another modelers plane.

How old are your 6EX's?

Here is a thread:

http://www.rcgroups.com/forums/showthread.php?t=1220017

Mike

[dahawk]

Thanks Mike,
Sounds like a very plausible explanation. I have (2) 6EX's , both a couple of years old. Actually bought the 2nd one slightly used as a backup. There were some guys there with Futaba 72's but I don't think there's a possible interference issue as the rx's are Fasst.

-Hawk

[rcers]

No 72MHz is not the issue as you point out. I suspect it was just what the others list but I would have the GUID checked out since one is used and may be quite old.

[pmullen503]

Transmitters without model match will happily control as many receivers as the TX is bound to. Allows you to use multiple receivers in a plane or use different model memories to control the same plane.

One knock against Spektrum's model match is that you can't copy a model memory, change a parameter or two, and fly the same model without rebinding the Rx to that model memory.

[A.T.]

Originally Posted by dahawk

Yikes ! Need a little Forensic Pathology here.
<snip>

Had her turned paralell to the field, heading 090. Then, switched models over to the C-182 on the Futaba 6EX. All good so far. Control surface checks. good. Taxi to runway. Take off roll, rotate... all good. Smooth as silk.
<snip>
-Hawk

A very familiar story.
. Transmitter On First - Off Last

Unless your receiver is turned off and or Power battery disconnected after every flight,
your model will continue to react to your 6EX transmitter commands.
Only JR/Spektrum Tx have model match, but a similar device such as
Modelguard - Model Choice Warning System for Hitec & Futaba.
The major downside to "Modelmatch" is that user can leave a Lipo connected and it will
continue to be drained by the ESC until it is damaged beyond recovery.
Even if receiver is switched, switch controls only power to the servo, the ESC is still armed and draining battery.

Much more information available under sub sections
"Battery Care, Performance & DIY Battery Packs."
and
"ESC & BEC - Setup to prevent majority of all RF Problems, Brownouts & Crashes" below
"Radio Systems, Accessories, Alterations and FAQ" at
Alan's Hobby, Model & RC FAQ Web Links

Alan T.

[rcers]

Originally Posted by A.T.

The major downside to "Modelmatch" is that user can leave a Lipo connected and it will
continue to be drained by the ESC until it is damaged beyond recovery.
Even if receiver is switched, switch controls only power to the servo, the ESC is still armed and draining battery.
Alan T.

Yes but you have saved a plane - and this had the real potential to INJURE someone in the pits, a spectator or someone at the nearby soccer fields (that is my local club).

That is not a downside in any way. ModelMatch rocks.

Mike