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Old Oct 03, 2011, 04:52 AM
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Dublin, Ireland
Joined Nov 2010
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Pilot error or Radio problem???

I've been flying rc aircraft for about two years now and have 7 planes, mostly warbirds.

Last week I was flying my Parkzone Me109 at about 60 feet altitude when during a gentle left bank, she rolled onto her back and nosedived into the ground destroying the plane. Now I know about this model's tendency towards tipstall but I have flown her successfully on five occasions prior to this with no issues. The rx light was still a steady orange after the flight so there's no indication of a radio problem (I use a Spektrum DX6i). I had carried out a range check prior to flight (my normal practice) and it passed this ok. All control surfaces were working normally pre-flight. At the time, I chalked it down to tipstall even though I had her flying at reasonable airspeed and the bank was gentle.

However, two days later, I was flying my PZ Wildcat when during a left bank, she too rolled onto her back and nosedived. Luckily I had the altitude to save her. As I was bringing her in for a landing, she again twitched to the left but I landed her safely. Again, there was no indication of a radio problem from the rx.

This got me thinking about another loss of control I had 4 weeks ago, when on the fifth flight that day of my PZ Mustang, I launched her cleanly and she took off climbing at a good angle when for no reason, she just veered off to the left and crashed.

So in all three incidents, the planes went left and nosedived despite opposite aileron input from me on the DX6i. The aircraft all had sufficient airspeed so I'm sure it wasn't a case of them stalling. I fly three to four times a week and have done so for the past two years so I'd class myself as a competent flyer. However, these incidents, so close in succession, have made me draw the conclusion that I have a radio problem, albeit an intermittent one as I've had some great flying sessions in between these crashes/near crashes. I've checked HH's service bulletin on the DX6i and my radio is not one of those listed for a recall but I think there is definitely something wrong with it.

Any opinions?
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Old Oct 03, 2011, 05:31 AM
Right Rudder
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USA, FL, Orlando
Joined Nov 2010
9,673 Posts
Go see about flying somewhere else.

I do not believe you have done anything wrong with your setup as you seem to be experienced.

Remember, 2.4G "Spectrum" is low powered unless you have a license which means Higher Powered. If you see a news Helicopter chances are that they are transmitting their signal via a License 2.4G device and watch out.

I just came back from a WATTFEST Fly-In event that was all Electric near the West Cost of Florida and a very expensive 12-Cell Li-POLY EDF Jet that cost over $1,000 went in after a few seconds in the air. My own large EPO foam Me Bf-109 went in right after take-off and did exactly what you are describing.

Just look.....
http://www.rcgroups.com/forums/showp...&postcount=114
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Old Oct 03, 2011, 06:56 AM
Gravity's a harsh Mistress....
southernmd_man's Avatar
United States, MD, Lusby
Joined Jan 2007
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Sounds like a high speed tip stalls. How fast were you going, and how sharp of a turn were you making? At higher speeds you want your turns to be long and wide. I lost an FW-190 while making a shape turn while dog fighting. My turn was too sharp, lost lift on the wing, and motor torque rolled it over and down it came.
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Old Oct 03, 2011, 09:57 AM
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USA, VT, St Albans
Joined Jun 2007
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Quote:
Originally Posted by Irish Viper View Post
during a gentle left bank, she rolled onto her back and nosedived into the ground destroying the plane. I chalked it down to tipstall even though I had her flying at reasonable airspeed and the bank was gentle.

PZ Wildcat when during a left bank, she too rolled onto her back and nosedived.

PZ Mustang, I launched her cleanly and she took off climbing at a good angle when for no reason, she just veered off to the left and crashed.

Any opinions?
At least it's consistent. Without seeing a video of you flying we can't be sure it's pilot error.

Let's assume it's not. PittSpecial theory may be correct.

I had my 109 pitch up violently shortly after launch and didn't respond to inputs.
The Rx light gave no indication of an error. This Rx was a DSM2 and my DX6i is DSMX... one of the recalled ones.

Another theory, since it's consistent on all 3 planes, have you been copying models in your Tx and making changes when you get a new plane? Like a template? There could be a setup problem that you inadvertently copied to all planes.

Check your servo throw % in BOTH directions. Perhaps your left input % is lending a hand in causing a tipstall like southernmd_man suggested?
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Old Oct 03, 2011, 10:58 AM
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Dublin, Ireland
Joined Nov 2010
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Thanks for the opinions guys.

Where I fly is in a very large park with no powerlines or cellphone masts nearby so I'm fairly sure its noise free. I do 90% of my flying there and apart from the three recent crashes/near crash, I've had trouble free flying.

I never copy templates over to new models and I start with a clean set up for each plane. The servo travel has been checked on the planes and it is the same for both ailerons.

I fly scale all the time with large wide banks so its not "yank and bank" flying and so I'm pretty sure its not tipstall that caused three planes to flip over to the left on all three occasions.

I've lost confidence in the DX6i and its put me off using it to fly as I don't know if my plane is just going to suddenly go out of control and enter a death dive.
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Old Oct 03, 2011, 11:35 AM
Right Rudder
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USA, FL, Orlando
Joined Nov 2010
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Quote:
Originally Posted by Irish Viper View Post
Thanks for the opinions guys.

Where I fly is in a very large park with no powerlines or cellphone masts nearby so I'm fairly sure its noise free. I do 90% of my flying there and apart from the three recent crashes/near crash, I've had trouble free flying.

I never copy templates over to new models and I start with a clean set up for each plane. The servo travel has been checked on the planes and it is the same for both ailerons.

I fly scale all the time with large wide banks so its not "yank and bank" flying and so I'm pretty sure its not tipstall that caused three planes to flip over to the left on all three occasions.

I've lost confidence in the DX6i and its put me off using it to fly as I don't know if my plane is just going to suddenly go out of control and enter a death dive.
First, you do not need to have any "visible" tower masts around to determine if your area has a trashy RF, typical misconception. A news Van perhaps nearby "or" a Helicopter could be flying nearby and you may not noticed but, the density power of those Video Transmission devices are much more powerful than your "RC HOBBY" equipment and all it takes is a few seconds and your model takes a dirt nap.

I am pretty sure you have a broken internal Antenna connector assuming you do not have one DX6i that has been in the recall list for the Pots!

Check Horizon Hobby or better yet, Spektrum Web Site and see if you Transmitter has any Recall Listings (Serial Number Check).

My buddy had lots of issues with his DX6i and I took it in my hands and I started doing taxi tests on a large High School Concrete Band practice area with his Modified Hobby-Zone Super Cub right after he crashed his Park Zone T-28 and to our horror the model just Stopped Responding and after 5 seconds later it came alive again!!!

There is a large amount of threads at the Radio Section about the DX6i and do some searches if you have time to read, otherwise, just call Spektrum Technical Dept. and see if they can help you determine if your radio needs to be shipped back to them.

Carlos
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Old Oct 03, 2011, 12:07 PM
Gravity's a harsh Mistress....
southernmd_man's Avatar
United States, MD, Lusby
Joined Jan 2007
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Just thought of something else...are you using an AR500 RX? There were issues with with that model RX, which is one of the reasons the AR600 came into being other than one more channel.

On another note, I've had my DX6i sence they were released and haven't had any issue's other then problems binding with old AR6000's.
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Old Oct 03, 2011, 08:30 PM
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Joined Jul 2011
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Second the ar500 question, I've had similar dodgy things happen on those. Another thought is if you were using the same battery. I had a lipo go out mid-flight and it made all of my control surfaces begin to have seizures (not stop working seizures, like out of control malfunction style seizures).
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Old Oct 03, 2011, 08:49 PM
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VA
Joined Feb 2009
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Quote:
Originally Posted by Irish Viper View Post
I've been flying rc aircraft for about two years now and have 7 planes, mostly warbirds.

Last week I was flying my Parkzone Me109 at about 60 feet altitude when during a gentle left bank, she rolled onto her back and nosedived into the ground destroying the plane. Now I know about this model's tendency towards tipstall but I have flown her successfully on five occasions prior to this with no issues. The rx light was still a steady orange after the flight so there's no indication of a radio problem (I use a Spektrum DX6i). I had carried out a range check prior to flight (my normal practice) and it passed this ok. All control surfaces were working normally pre-flight. At the time, I chalked it down to tipstall even though I had her flying at reasonable airspeed and the bank was gentle.

However, two days later, I was flying my PZ Wildcat when during a left bank, she too rolled onto her back and nosedived. Luckily I had the altitude to save her. As I was bringing her in for a landing, she again twitched to the left but I landed her safely. Again, there was no indication of a radio problem from the rx.

This got me thinking about another loss of control I had 4 weeks ago, when on the fifth flight that day of my PZ Mustang, I launched her cleanly and she took off climbing at a good angle when for no reason, she just veered off to the left and crashed.

So in all three incidents, the planes went left and nosedived despite opposite aileron input from me on the DX6i. The aircraft all had sufficient airspeed so I'm sure it wasn't a case of them stalling. I fly three to four times a week and have done so for the past two years so I'd class myself as a competent flyer. However, these incidents, so close in succession, have made me draw the conclusion that I have a radio problem, albeit an intermittent one as I've had some great flying sessions in between these crashes/near crashes. I've checked HH's service bulletin on the DX6i and my radio is not one of those listed for a recall but I think there is definitely something wrong with it.

Any opinions?
I've had the exact same thing happen to me with both my pz corsair and pz t 28. The planes both gently rolled to the left and went face first into the ground. If it happened near a grove of tree's, i think i have an explanation, a fellow club member described my issue in detail. i was not going to slow but rather the light wind going over the trees made a sort of turbulent eddy at the edge of the trees and when i flew near them slow enough with one wing in the eddy and the other in the wind i would have a sort of tip stall but with more gentle and irreversible characteristics.

http://www.google.com/imgres?q=graph...kpbT8BA&zoom=1
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Old Oct 04, 2011, 12:25 AM
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Canada, ON
Joined Aug 2007
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Quote:
Originally Posted by NoiseBox View Post
Second the ar500 question, I've had similar dodgy things happen on those. Another thought is if you were using the same battery. I had a lipo go out mid-flight and it made all of my control surfaces begin to have seizures (not stop working seizures, like out of control malfunction style seizures).
Interesting... never knew AR500s are notorious. I had lost 2 planes with (the same) AR500 receiver (a GWS AT-6 and balsacraft Spitty.) The AT-6 crash fits the description, rolled on its own and won't respond to up elevator, whereas the Spitty just stopped responding 15 seconds into her maiden flight when she's still not trimmed (and so nosed down at almost full throttle.)

These 2 incidents happen on 2 different fields, so can't be the location. Though the Spitty crash did happen near a high voltage power line.
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Old Oct 04, 2011, 12:52 AM
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United States, LA, Shreveport
Joined Jul 2010
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I remember reading a while back that it wasn't the AR500 that was bad, but a batch of AR500s that were. Now, I'm not going to knock on wood because I'm not superstitious, but I fly close to WAFB with my DX8 and DX6i. I use AR600s, AR500s, one AR8000, one AR6110E, and one AR6200. I also fly quite a few UMs and UMXs. WAFB has Apaches, A-10s, T-38s, and B-2s. About 500 hundred yards from my place is the rotating radar mast. I've never had an issue of losing control via signal loss. My radio equipment has been rock solid even when any of the previously mentioned aircraft are flying around.

Now that I think of it, I've flown with 3 other guys, who use Spektrum/JR and they haven't had any problems either; and we were flying ON base. With that said, you could very well have a faulty radio. I hope you get it figured out.
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Old Oct 04, 2011, 01:00 AM
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Canada, ON
Joined Aug 2007
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I too have yet to lost any of my planes with AR6110(e), and the AR500 had had a long career on the GWS AT-6 (2 seasons) before the first crash. The second time it went up after the AT-6 crash was a year later on the Spitty, so maybe it's just that particular receiver. Doesn't skip a beat on the ground, even during range check though.
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Old Oct 04, 2011, 05:34 AM
Right Rudder
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USA, FL, Orlando
Joined Nov 2010
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Guys,

I have Spektrum Radio gear myself. I do have 72Mhz as well.

For those model on Spektrum, I have the DX7 as the Transmitter and the following Receivers: AR500, AR600, and AR7000 with satellite.

Let me tell you, I used to turn ON my transmitter on the Spektrum DX7 just like I do with the 72Mhz and it only took two (2) crashes until I realized that the Ultra Deans connectors (Battery-to-ESC) were at times hell to connect and at times I made a false connection such that the RX though it had a brown out. The Receiver then goes into a flashing mode meaning it thinks it is in bind mode. Some experts say that is normal and the RX is just saying or indicating it had a Brown-Out.

In any case, I activate (Turn-ON) my model first and then, turn-ON the Transmitter last. Believe me, there is no issue doing it this manner if you check any Spektrum instruction manual it does say you can do it either way. Remember this is a digital system and the model will just sit and sit there until it see's the GUI identifier of the Transmitter.

I truely believe that my crashes were as a result of lost Range due to the Receiver Flashing its Light and flying the model in this condition.

I have NOT had any issues ever since I changed my methods as stated above.

Happy Landings!
Carlos
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Old Oct 04, 2011, 08:51 AM
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Joined Mar 2011
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I had a problem last spring where a buddy maiden my maxjet on my DX6i, was flying great, then shut off and lost controls,then came back on and he saved it just to bring it around to do it again and down it went.Later that week I was flying pz109 and heard the motor shut off then back on. Did same on my pztrojan.After talking to other pilots about this no one had a clue,thinking back my transmitter did fall from my truck bumper once a month before,so I went and got brand new DX7,guess what,same problem.So what I was went through and rebound all my planes an hav'nt had a problem since,what cause this I don't know,best part! I get to buy more planes for the DX7
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Old Oct 04, 2011, 11:41 AM
To Have & To Hold
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Joined May 2010
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How about borrowing another radio to fly five times on two different planes to compare.
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