DLT

My Feedback: (48)

Saw two different flying buddies planes go in today. They were flying at different times and both went in at 20-25 feet from each other. I didn't think spectrum 2.4 radios would get interference. It was really strange that they were flying in the same area when they went in.

Rcpilot

My Feedback: (78)

You have no idea of the setup on the planes? No details? No post crash investigation?

Or maybe you do know and would like to elaborate?

Are these small sport planes? What RX's? Are these giant scale gassers? What are they doing for power to prevent brown-outs? How many servos? What batteries? Li-ppo? MH? Nicd? 6V? 7.4V? Regulators? Voltage capacitors installed? Not installed?

Need more details. Posting to say you saw 2 airplanes with Spektrum crash today means nothing. Details man!!

DLT

My Feedback: (48)

Hey mr RCPilot moderator man....No I don't know ALL the details but I can tell you that one was a well kept SNJ and the other was an LT 40 well kept as well with charged and checked batteies...my point is why would 2 different planes go down in the same area at differnt times when they are on the 2.4 system. Also neither one of these planes had any priors. The fact that they went down in almost the same location would indicate something a little weird.

PacificNWSkyPilot

My Feedback: (19)

Exactly. If they set them up the same, and both had some issue, then they both did. How long had they been flying? What was the voltage of the battery packs? What kind of switches? Big planes? What size? What was the setup?

Jim

onewasp

DLT

Hell______, that means absolutely nothing other than two A/C went in.

The Spektrum/DSM2 is in its third year. I have flown it since the first shipment in 2006.
We have fields loaded with it. Since 2006 I have seen zero crashes (newbies included) on ANY DSM2 system. Not even pilot error, and we've got a few new fliers on it (matter of fact ALL the new fliers are on it).
While the FASST arrived quite late (in comparison to Spektrum) they too have the same no crash record no failure record.

I have no idea what happened but you might as well blame it on the plane color. Or the guys mother; or the time of day as there is zero data to support a single thing even the validity of the "Two planes went in today."

You want help on these sites then learn the basics ___ based upon your post you haven't learned yet.

It's that simple. And it's that harsh.

BuschBarber

My Feedback: (2)

It is important to report unexplained crashes, but without detailed info, and just stating that there were 2.4 radios in each plane, could start a panic amongst 2.4 users. It is odd that both crashes happened in the same area of the field.

I have an H9 P47-150 with an AR9000 Rx. I was making an Upwind pass at 100'. I was facing N and the plane passed me heading E. In the SE corner of the runway, the plane suddenly rolled 180deg right, to inverted. I rolled back to level, dropped the gear, and landed. I replaced the Rx with another, raised it up to just under the canopy, and put the Satellite Rx on a 36" extension in the tail. A couple of days later, I flew again at the same field, without incident. On the second flight, however, the plane rolled the same way at the same point on the field. I dropped the gear and landed.

I replaced the 821 Aileron servos with Analog 645MG servos as that was all I had. I also replaced the servo extensions to the Rx. The problem has not reoccurred. I do not believe it was RF interference or a malfunctioning Rx. Since it only affected the Aileron channel, and I had a separate servo for each Aileron, on separate channels, mixed, I believe it was one or more servos or wires that malfunctioned.

It is important to provide as much info as possible. Type of TX and Rx. Number of Satellites and location. Gas, Glow, or Electric. Size, number, and type of batteries. Number of servos and type of servos. 3D, Scale, Aerobatic, and size of aircraft. Weather!!

I have seen 72Mhz glitch in the same area of the field due to RF. I have also seen wind turbulence roll off Trees and Bushes and cause unexpected crashes

DLT

My Feedback: (48)

Sorry I brought it up guys...Rc Universe use to be a nice place but now seems to filled with brand perfect defenders. Is there anything perfect??

onewasp

Nope, but it is until you list where it is not.

This CAN'T be new news to you. Your profile displays 18 years of experience but you couldn't tell it by the quality of your post.

Our plea is simply get with it ____ give us some facts not some generalized statement that is neither true nor false as it says nothing.

BuschBarber

My Feedback: (2)

It doesn't matter if it was Spektrum/JR, Futaba FASST, Airtronics, XPS, etc. Perhaps there was an overreaction to the fact that you reported 2.4 systems were involved.

There are those who have convinced themselves that 72Mhz or 6 meters is safer because everyone is running to 2.4, but I feel much more secure since I switched to 2.4. That does not mean that these systems are immune from everything.

BuschBarber

My Feedback: (2)

I am using two XP9303 Tx's. One has the Spektrum module and one has the 72Mhz Synthesizer module. I am half converted to 2.4.

PacificNWSkyPilot

My Feedback: (19)

Not JUST that 2.4's were involved. It was that yet ANOTHER Chicken little stepped up and suddenly the 2.4 sky is falling again, but no, I don't have any facts other than they were both in the same STATE that day.

I spent 25 of the last 30 years listening to every fool talk about how his dumb-thumbing was actually a 'hit" or RF noise. That was 72, and as it improved, the storiues did too.

2.4 is actually beyond the understanding of most of these guys, so much like this latest report they're going for the basic approach with the foolish "I was there and saw it all". As if that is going to impress those of us who have actually taken the time to learn how these work and what weaknesses they have and how, why and when they show themselves.

So, yes, you may feel that there may have been an overreaction. I prefer to state that I do not suffer fools gladly.

Jim

Rcpilot

My Feedback: (78)

Best line in this thread so far. [sm=lol.gif] LMAO!!!!

alan0899

G'day Mate,
We had a plane crash today, & yes it was using a Spektrum DX7 radio.


If I had posted that statement, while the statement is true, the facts are that, the crash was caused by the pilot, he lost most of his altitude, during his base leg turn, didn't add power, to make it to the start of the runway, shredded it through the top of a low bushy tree, that broke the prop, & the plane just fell to the ground, before it made the strip.
Minimal damage, one broken prop.

No-one blamed the radio, because it was the pilot that made the error.

And no-one on here is a brand perfect defender, but the radio should be the last thing that can be blamed, after a crash, but it is almost always the FIRST thing that is blamed. The radio technology we have today is extremely reliable, & robust, BUT, no-one can allow for the human factor, although Spektrum/JR have tried, with model match & so on.

Have a great weekend, I have.

BarracudaHockey

My Feedback: (11)

2.4Ghz are not "immune" to interference, nor are they perfect. They are MUCH more resistent to the interference that can plauge 72 mhz installations such as ignition noise, metal rubbing, etc but they aren't an excuse for improper radio installation.

PacificNWSkyPilot

My Feedback: (19)

The last two posts BOTH had excellent statements;

alan0899: "And no-one on here is a brand perfect defender, but the radio should be the last thing that can be blamed, after a crash, but it is almost always the FIRST thing that is blamed."


BarracudaHockey : (paraphrased) "2.4Ghz are not "immune" to interference, nor are they perfect / they aren't an excuse for improper radio installation."

Two EXCELLENT perspectives.

And I'm giving BarracudaHockey a hundred points just for the cool name.

Jim

AJsToyz

I had a 2.4ghz plane go in, FASST system, It was NOT the radio that failed. Had a servo on the right wing strip out. I purchased the planed used and flew it this way. It was still the owners fault < ME > for not totally going through the plane and making sure 100% that all the equipment was in good condition. I also had a friend take one in on 72mhz , plane acted like it was hit with another signal. Most likely it was a bad switch or a week battery. My friend was so busy checking everything else he didn't think low battery and charged it before we had a chance to check it. My Heli has the Rx sitting almost directly on the motor and speed control, no troubles from the Futaba or Spectrum. It was on PCM but it was nice to do away with the long antenna wires.

Andy

seanreit

My Feedback: (60)

I crashed a Turbine Jet on 2.4 last year (not due to the overamp issue). I blamed a million things before I would get to 2.4. Truth is, to this day I have no idea why it went in uncontrolled. But I don't blame 2.4. That crash cost me somewhere near $5,000.00.

I have several hundred turbine flights on 2.4 to date. All of my jets are on it. FWIW from a guy who is too big an A-hole to be flying 72 meg

readyturn

My Feedback: (9)

You mean that you can blame the radio for the aircraft rolling up inverted and going in?

Darn, I will have to remember that.............. I, too, lost a jet while flying on 2.4.... But I, not the radio, messed up the control throws. []

DLT

My Feedback: (48)

I admit that my first post lacked a lot of details but here they are as I saw them. Two pilots flying on 2.4 with by the book installation (battery,servos, receivers,etc.) with both these planes having no prior incidents at all. We always check our batteries before we go up period! And that was the first thing checked after the two crashes. We fly on a large Navy field, wide open and no trees to factor in. Wind was dead calm so that wasn't a factor. Let me say i'm not against Spectrum as many of my friends in the club fly them. I have flown for 20 years and have logged about 1000 hours of flying time and have instructed 18 of these years.

What I saw yesterday was almost unbelievable. These two aircraft suddenly at an altitude of about 150 feet rolled over on their own with no pilot input and went straight in...now I think i've had enough experience with this kind of thing to know if was pilot error or mechanical/electronic failure, but for both of them to go ape in such a manner was just to extremely rare. I might mention that both incidents happened 75 yards out in almost the exact location. Both planes came to rest about 25 feet apart. That is a very rare thing to happen (especially on such a large field). Their flight times were about 15 minutes apart...so they weren't flying at the same time and both planes they were flying had logged about 5-8 hours (not the pilots but the planes). These are the facts gentlemen so let the degrading and insults continue...Fly safe

onewasp

DLT

Quote ".
......These are the facts gentlemen so let the degrading and insults continue...Fly safe"

Quote

Nope , no disparaging remarks at all.

While this is a LOT more info. than your initial posts it still won't result in anything
higher than slightly informed conjecture.

The loss of signal on a 2.4GHz (confined to Spektrum DSM2, JR DSM2 and FASST as I have no experience or even much interest in the others) would be expected to produce low throttle and neutral or last position depending on the programmed input.

IF you mean the aircraft received what looked like a slow rolling input then that simply isn't in the cards as on 2.4GHz you either have it or you do not based upon GUID.
There is zero chance of another input as usually exhibited by 72MHz: 50MHz systems again, due to GUID.
The only way I can justify a single control input (assuming that is what you saw) on 2.4GHz is through a servo failure of some sort.
That's it.
The system doesn't function the other way___period. All or nothing ____ and I've never seen that condition develop in all the flying I've done on 2.4GHz (and in all the flying which I've observed) since 2006 _____.

MOST suspect is the battery condition. I KNOW you said they were tested and were fine.
However, what was the pack capacity, voltage including a reading of at least tenths, nominal pack voltage 4.8v or 6.0v or 6.6v immediately prior to the last flight?????
And on we go seemingly without end as we need the power system (Gas; Glow; Electric). Then component location _____ truly , NO end.

If you can't nail the failure mode at the crash site then your chance of enlightenment on the web is but a fond hope.
A lot of study later (it once took me two solid weeks to dissect a six meter crash) and it might be possible ____ but you would have to have taken what might be considered exhaustive notes/readings at the crash site.

Obviously you are not going to receive an answer that satisfies you.

The rest of us are stuck with very mildly informed conjecture.

Here is my GUESS; a complete set of conditions (unknown) NOT involving the radio itself and likely either installation or battery triggered.
That two did substantially the same thing at substantially the same spot __ pure happenstance.

As I said you're not going to believe anything other than your interpretation of what you saw.
There is no answer which is either complete or factually justifiable. Not my GUESS and not your observation.

There it will have to lie.

This I will say ____ of all the systems out there____2.4GHz is the LEAST likely to fail from external interference and in the mode you described.


BTW "someone" is going to say "2.4GHz is not totally immune to interference."
NO S*** !! ___and the world is not immune to disappearing either!

DLT

My Feedback: (48)

Your last paragragh says it all....and sudden means sudden not slow...sincerley guys i'm sorry I posted to begin with...cheers

PacificNWSkyPilot

My Feedback: (19)

I was like the fifth post and asked these questions shown above. These were the most BASIC questions I would ask, and they are still unanswered.

Degrading questions and insults? Disparaging? I should think these would almost be MANDATORY in this case. Even worse is that rather than to go and get some answers you think we're going to be impressed with your reiteration of almost the same information you initially gave us, the same story with one or two more details.

If you would like constructive criticism then allow me. I'd suggest that in the future before you post something that is nothing more than a broad generalization with no facts to back it up, that you instead take a week, take the planes apart with the guys, and FIND OUT what the cause was. GET THE FACTS.

This was like saying that because two Irish guys crashed at the field in about the same place that day that Irishmen are dangerous and unstable flyers. Actually, knowing some of my Irish friends who fly that may be far more true than your generalization, but I think despite my poor choice of examples that my point has been made here. Just kidding about the Irish guys, I'm Irish, and Scottish, and....whatever will keep me out of trouble here.

Jim

onewasp

DLT

Quote
"Your last paragragh says it all....and sudden means sudden not slow...sincerley guys i'm sorry I posted to begin with...cheers
Quote

My last paragraph was this:
Quote
"BTW "someone" is going to say "2.4GHz is not totally immune to interference."
NO S*** !! ___and the world is not immune to disappearing either!
Quote

You have TOTALLY misinterpreted what I meant to convey.
What I meant was that your initial assertion of having been "hit" if you will, had about the same odds of relativity as did the Earth's sudden disappearance.
That is to say, "possible" but so unlikely as to be absurd.

To have been "hit" ( again), 'if you will', twice on the same day is beyond those already absurd odds by at least a factor of X2.

A sudden control input was/is indicative of outside interference on 72/50/27 MHz.
BUT it is out of the realm of perceivable possibility with 2.4GHz. The system simply DOES NOT RESPOND THAT WAY!

I would NOT presume to say that "XXX" positively was the cause of what you indicate you saw.
I WILL say that it was NOT because of interference on 2.4GHZ.
NOT with a direct command being given and then processed by the radios on 2.4GHZ in two separate A/C which resulted in sudden application of ailerons causing a sudden roll, with an occurance rate of twice in 15 minutes.
Did not happen!
Not even if you had UFO's from the planet K-Pax operating in the area.

Now is it clear??

edwal07

Simply amazing!
x+y=z ! BECAUSE x and y are close together and we added a + sign they must equal z! True! But what is Z? We will never know unless you know at least what x or y is! You can profess to know z but without anyother information you still have Z! ZILCH!
Just a point!
I also had a problem with 2.4 (Spektrum), it took me over a 2 week period to isolate and finally come to a definitive answer. I have 5 gassers all on 2.4. Extremely care on installation and location, remote extensions moving them into the turtle deck, and careful with metal, wiring and routing! I had intermittent problems (back to idle, erattic control) with only one plane. I checked and rechecked for problems, wiring, routing, metal to metal contact, batteries, and anything else you could imagine. Nothing!
I always use dielectric grease on my plug insulator when I install the plug in my engines! I had had a hard landing on one end of the runway just before the sod and there is a lip there and the plane bounced up but recovered, not nice but got it home with spread gears. Anyway to the point, checked everyting over, nothing out of the ordinary but some grass on the plug cover, cleaned and checked, ok! NOT!
Next weekend flew great no problems until I removed the plug to check another engine we thought had a bad plug (spares at home)! Returned the plug to the engine, started and took off, great flight, except when on final, engine went to idle, throttle came back to normal but with erattic control, going where it wanted, killed the ignition, instant control, dead stick in to runway!.
The problem ended up being a small slit in the rubber insulator inside the plug cover. The hard landing had caused the cap to be pushed back and the coil around the tip of the plug pushed thru the insulator causing the small slit, nearly invisible, and only visible if you take the cap apart. Flying was possible after the hard landing due to the dielectric grease kept it from arcing to the cap, however after removing and reinstalling the plug (the plug was wiped off) the dielectric was removed and allowed the arc to reach the cap. I noticed this after removing the plug cap and seeing the black marks associated with arcing inside the rubber boot! Lesson learned, lesson earned!
My point is, nothing is impossible, everything is suspect until you find the answer, but don't identify the culprit and charge it with the crime until you are sure it is the problem. And once you do identiry the problem, especially if it truly is a hard one to find, it gives you a great feeling!
I love the 2.4, have a nice flying season!

DadsToysBG

My Feedback: (35)

Another 2.4 story. While helping a friend yesterday (Sunday) his plane suddenly for no reason went into fail safe and all the flight surfaces went in different directions. Did a reboot and everything seemed fine and then it happened again. Some said the radio 2.4 was bad. I said no, it's battery. sure enough put a meter on the 6v battery and it showed 3.8v. It was the radio telling us the battery wasn't good enough. Can't blame 2.4 for this one. Dennis