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strange crashes

Old 07-08-2009, 02:21 AM
  #1  
humpy64
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Default strange crashes

I have been intensively flying for two years and am a reasonable flyer. However, I have lost five planes very strangely despite meticulous preparation.
I have been flying normally and the plane suddenly turns down and goes vertical ending head on into the ground. I have done this from three mistakes high to l00 feet. There is no saving the plane.
My batteries are always charged fully, I use quality servos, I check and double check my settings and the trim is always right. The motors are excellent and always serviced and don't quit.
I cannot tell if the transmitter, a Spektrum DX7, responds because it happens so fast. The extra "antenna" is always at the factory position.
Today, I let an expert flyer fly my best plane a Super Sportster 120 and the exact same thing happened to him on a windless day after he was in the air about five minutes. Plane had fuel in it but was so demolished we couldn't gather anything from the "autopsy."
This has happened to a Sig Sr Kadet, two Super Sportster 60s, a Messerschmidt and the one that crashed today.
Any ideas?
Old 07-08-2009, 03:55 AM
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beepee
 
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Default RE: strange crashes

Yea. Quit doing that! You have lost a lot of very good aircraft to a faulty system. Apparently, you have a radio problem that needs expert investigation and fixin'. NOW!

Good luck,

Bedford
Old 07-08-2009, 04:53 AM
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jetmech05
 
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Default RE: strange crashes

Did the service bulletin effect the DX 7? wether it did or not doesn't matter sounds like you either have interference issues...yes 2.4 is subject to interference from gargage door openers and wireless phones I think it is......send in your transmitter and at least one receiver that crashed and get it checked
Old 07-08-2009, 05:38 AM
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airbusdrvr
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Default RE: strange crashes

When I first started flying a neighbor gave me an old AM radio system. But shortly thereafter I bought a new Hitec Optic 6. I was new to the hobby, but I personally knew that some of my crashes were not me. I had lost control of the plane. After about three or four of these crashes with different planes and receivers, etc. someone suggested I get my transmitter checked. In addtion to sending the transmitter back for check-up I bought a new Hitec Eclipse 7. The Optic 6 came back with some cryptic repair note and the Eclipse 7 was doing fine. I sold the Optic 6 and continue flying the Eclipse 7 after nearly five years with no issues. Even though I have changed most of my planes to 2.4Ghz, I still have a couple on 72Mhz and the Eclipse 7. My suggestion would be to buy a JR X9303 and give the DX7 to someone you don't like.
Old 07-08-2009, 05:43 AM
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airbusdrvr
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Default RE: strange crashes

humpy64, just saw your Huntersville location. I used to live west off exit 33 down by Stutts Marina off Brawley School Rd. But that was 25 years ago when there was only one traffic light between by house and downtown Mooresville.
Old 07-08-2009, 06:41 AM
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Default RE: strange crashes

humpy64

Do any of the failed aircraft have any one common part in the radio system that you swapped into each plane?

The DX7 is the best radio I've ever used but, I did have a similar situation. I lost a ParkZone Corsair three times in the same manor. I finally found a small hole in the LiPo battery. It was from a motor mount screw that had punctured the battery and the system would short out, losing the radio link.

You may have a bad wire in the battery, switch harness, or receiver. It only take a second of power loss to lose the link. It can be restored if you turn the transmitter off and back on, but who has time to do that?

I don't believe radio interference is an issue. The DX7 uses Dual Link, two seperate signals.

Old 07-08-2009, 09:09 AM
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humpy64
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Default RE: strange crashes

thank all of you for your great answers.
Old 07-08-2009, 10:27 AM
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Default RE: strange crashes

If your using different receivers in each plane, then the common link would be the transmitter. If I'd have been in your shoes, I wouldn't have flown the radio without having it checked by Spektrum after I'd seen two similar failures!

When we had to build the airplanes we flew, I guess we were more cautious about risking all our hard work, with a questionable piece of equipment. I know that Spektrum is receiving some bad press at this time. This should have triggered a more cautious approach for you! Sorry for your run of bad luck and good luck getting a fix!
Old 07-08-2009, 10:35 AM
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ChuckW
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Default RE: strange crashes

I agree, sounds like a radio system issue. Could be receivers, could be the transmitters.

Also, what kind of batteries are you using? How many cells? what capacity? what are you using to charge them?

I'd take a close look at the switches and all the connectors too.

If everything looks good, I'd call Horizon and send the transmitter and crashed receivers to them. These guys have great service and will likely make it right. The DX-7 is a great radio system but yours may have a problem.
Old 07-08-2009, 10:35 AM
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Default RE: strange crashes

Hi!
First of all ...Is your Spektrum receiver one of the older models with reboot time of 1-3 seconds?
If it is... either send it in to Horizon for a up-date (which is free) or put a capacitor on it!. The newer ones has a much faster reboot time (milliseconds).

Second: A good way to know the battery capacity is to use a "volt-watch" in every airplane. Over here in Sweden I think this is more or less mandatory to use and I have not seen a airplane without it.
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Old 07-08-2009, 01:36 PM
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humpy64
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Default RE: strange crashes

thanks very much
Old 07-10-2009, 10:06 AM
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Default RE: strange crashes

The honest truth of the matter is; Humpy did not furnish enough information to really determine a route of Corrective Action. 1). Is the only common link componant of the R/C system, the transmitter? 2). Was the receiver also a common link (one receiver changed from one airplane to the next, then next, etc..?

Without answers to the above we really are only grasping at straws!
Old 07-11-2009, 08:54 AM
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jester_s1
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Default RE: strange crashes

Sounds very much like a transmitter problem to me. That's the only common link between the planes and all three had the same problem.
Old 07-11-2009, 11:43 PM
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jimmyjames213
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Default RE: strange crashes


ORIGINAL: jaka

Hi!
First of all ...Is your Spektrum receiver one of the older models with reboot time of 1-3 seconds?
If it is... either send it in to Horizon for a up-date (which is free) or put a capacitor on it!. The newer ones has a much faster reboot time (milliseconds).

Second: A good way to know the battery capacity is to use a ''volt-watch'' in every airplane. Over here in Sweden I think this is more or less mandatory to use and I have not seen a airplane without it.
does that work for 6v and 4.8v. if not which one does it work with. i would like to make one, but im a noob at understanding those drawings. if you could please get a pic of the back and tell/show which parts go to what. thanks

as for the topic.
its a spektrum, they do that now and again. send it in and get another one or even better get a futaba
Old 07-14-2009, 07:20 PM
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arniebud
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Default RE: strange crashes

I have been going thru the very same thing. I have lost 4 aircraft, some with just death spiral nose in, and 2 with out of control, see you later, off in the horizon till they crashed in the far woods. I finally came to the conclusion that the culprit was the only common part in each event, and that is the transmitter. I sent it off to Futaba, and they found that there was an intermittant disconnect in the battery to transmitter wire causing loss of signal to the plane.
Old 07-14-2009, 09:45 PM
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ro347
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Default RE: strange crashes

Ouch!!!!


ORIGINAL: arniebud

I have been going thru the very same thing. I have lost 4 aircraft, some with just death spiral nose in, and 2 with out of control, see you later, off in the horizon till they crashed in the far woods. I finally came to the conclusion that the culprit was the only common part in each event, and that is the transmitter. I sent it off to Futaba, and they found that there was an intermittant disconnect in the battery to transmitter wire causing loss of signal to the plane.

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