Dewalt17

Went out to the field today with my dad to do some flying and something very strange happened, heres the senario:

An experienced pilot was into his flight for about ten minutes. He was using an old gold box futaba on ch. 50. My dad and his instructor started the plane and taxied out. My dad has a Nexstar on ch. 46. As soon as the plane got off the ground i hear the instructor yelling somethings wrong!!! The Nexstar is out of control. The experienced pilot immediately went dead stick circled the runway and went in nose first as he was turning on final. "SMACK". (twigs and sticks).

I thought i read somewhere in the forums about high/low band radios. Was this what happened??? Frequency bled into my dads channel? The experienced pilot said he must have got a bad input that gave him full down elevator and that why he went down. I think he stalled the wing turning on final.(high performance low wing aircraft). We helped him pick up the pieces and then had him turn his
radio on and my dads radio on while on the ground. Didnt have any funny stuff happen. The instructor took my dads plane up 3 mistakes high and had the gentleman turn on his old gold box futaba. Plane started going out of control. So now we know its the radio but why does this happen????

TerrellFlyer

His radio and your radio bled over into each other's fre,one of the radio's or maybe both ,need a tune up by a pro. My guess is his radio is out of tune,every so often I send mine in for a check up just to avoid the same problem. When I turn on my radio,after checking no one is on same channel,I then hollor TURNING ON RADIO,. If some one has a problem then I turn my radio off,it's a good habit to get into,next time it could be worse.

MinnFlyer

My Feedback: (4)

You say he was flying an old "Gold Box" Futaba... Did you ask him if he had ever had it narrow banded? Back in 1991 the FCC required all of our radios to transmit a Narrower frequency band. Those old radios needed to be adjusted to meet the new requirements. Many people didn't bother.

LarryC

It might also be worth a check to see if the crystal frequency matches the channel on the radio. One of them may have been changed somewhere along the line without getting new stickers installed.

Larry

Doug D.

I would agree with Miniflyer. A lot of guys didn't get the Futaba G series updated. I've seen a couple a swap meets that guys where hoping to unload. If they don't have a Futaba update sticker on them they aren't really worth looking at. We had one guy at our club that forgot to replace an older reciever. Luckily it was caught before a mishap accured. Pays to stay informed and up to date. [&:]

raptor5900

My Feedback: (4)

it was probly radio interferance but where was the sun? it might have been the co-pilot thing?

Combat Addict

The nextStar has a AFS thingy that uses the sun to keep the wings level or some crap like that. What time of day was it? Was it sunny? What angle woud you estimate the sun was at during the flight?

Another thought. Was the airplane built right? Was it range checked?
You might look into these things to determine the cause of the crash.

Dewalt17

I talked to the guy who crashed and he said it was updated and had a gold sticker on the back of his radio. So i think that means he was ok.
Definately not the AFS, after a mishap yesterday my dad was finally convinced to leave it unplugged. Like i said before it was definately his radio. After we picked up all the pieces we checked for interference on the ground with his radio. Everything seemed ok so we thought we both got zapped by some interference. Then the instructor flew the Nexstar again and the other guy turned on his old gold box futaba to see what would happen. The plane started to go out of control with his gold box turned on and our instructor gained control once the gold box was turned off. So we know it has got to have something to do with his old radio.

Some guys at my field were saying the older radios were notorious for bleeding into other frequencies. Im not sure if thats true, all i know is when that radio was on bad things started to happen. Im just glad i wasnt flying because my frequency on my Nexstar is 48 which is even closer to 50 than may dads 46 is.

Doug D.

I think he should check that G seris futaba. If it was like one that I used to own the X-mitter modules could go bad. Rare, but it could happen. And the radio that was being hit by it should also have it's receiver checked just tomake sure. Better to play it safe than to loose it latter. [&:]

DBCherry

My Feedback: (4)

Certainly sounds like the older radio is broadcasting outside it's frequency. I'd politely suggest to him that he send it in for service before he causes serious damage or injury to someone. [:@]
Dennis-

Born to Fly

Would a failsafe set properly save the situation ?

Mighty Mouse-RCU

My Feedback: (145)

It would be interesting to try another airplane on channel 46 and see if it does it.
Fail safe probably would not have helped. If the signal is lost, it would have just gone into a pre-programed set of control surface/throttle. Not necesarrily a good thing.

Montague

Nope, failsafe in that case just allows you crash differently.

Double check all the crystals on both TXs and RXs to make sure they are what you thnk they are (as already mentioned). It is possible to have mis-labeled gear and get away with it for a while.

I'm not clear on what testing you did on the ground? You might try the following:

Turn on one TX and RX pair and do a range check. Then turn on the other TX and repeat the range check, with both TXs going out together. Repeat for the other RX. Then try each RX with just the opposite TX and see what happens. Note, you might want to disconnect the pushrods or just have one servo plugged in with no pushrod to prevent something from being driven too far over. You should be able to replicate the interference on the ground, but it might take some work. It's quite possible that when the proper TX and RX are close to each other that the weaker "leaking" signal can be ignored, but once in the air, it makes more of a difference.

Since he may have taken interference as well, his RX would also have to be overly wide band. I'm actually thinking something is mis-labeled or badly mis-tuned.

wsudrick

Minn,
I have an old Futaba AM 4ch. Not narrowbanded. I didn't know they could be. I am just getting in to RC and had planned on Getting a 6EXA. What's involved in getting the AM Futaba changed? Is it worth the effort/expense? Thanks.
Wayne

Doug D.

wsudick Contact Futaba and ask them if they can or will upgrade for you. May not be worth the expense. But check anyway. www.futaba-rc.com [&:]

DBCherry

My Feedback: (4)

I'm not sure, but I don't think they'll narrow band old equipment anymore. Thought I'd read that after a certain date they wouldn't. (?)
Dennis-

Dewalt17

The guy with the gold box was an old timer and had it narrowbanded years ago. After this incident the VP of the club said no more old radios can be used there anymore, at least not when anyone else is flying!![X(]

I thought maybe there was someone out there had this happen to them but i guess most people have thrown those old radios away.
I think we convinced this guy its time to get a new one. At least the only damage was to his own plane and not anyone elses. Its sad to see a plane go down like that, put a knot in my stomach. The sound of the crash is one i will never forget but im sure will hear again sometime in the future. I couldnt fly the rest of the day.

phread59

Hey Dennis, I heard that also. I believe it eas only a year or so after narrowbanding was mandated.

Mark Shuman

tucker1865

My Feedback: (6)

wsudrick....Radio South in Florida will narrow band your radio, but you will need a new reciever and they will charge for narrow-banding...probably best to get a new radio. I believe it's 35.00 to narrow and a rx is about 50.00...for 109.00 you get everything and a charger and servos, plus a guarantee.