jamesg33

On it's 35th flight my Patriot crashed while turning on to final approach. I think I got hit with radio interference as the plane suddenly started jerking all over the place and my inputs had no effect. After a couple of seconds it just rolled over and went in hard. Lots of damage, but fixable. The wing ripped off the plane but suffered no major damage. except for the landing gear area. Not sure how my pipe header got smashed, as the metal spinner came out fine.

Jim

randall1959

My Feedback: (11)

Since your header was lower than your spinner I'd say that took the force of the impact and that's why your spinner survived.

Broken

Looks like a fixer upper!!!

I wish I had a dollar for every radio hit that happend on final

jamesg33

Your're probably right Randall, I hadn't thought of that. It looked like the plane went in nose first, but I did lose sight of it at the last second so it probably pulled out of the dive a little before it hit.

Good one, Broken. After I wrote that I figured I'd get a few comments about the "radio interference"! This is actually the first time I'm using that excuse! The plane definitely went bonkers on me. Our field is adjacent to a working quarry, and I've had minor glitches before with this plane when it was at that end of the field. Not sure if they are using some equipment that is sending out signals on my frequency or what. Someone suggested they might be using high power CB's for communication, but I don't know whether that would do it.

Started to fix the plane tonight. Although it looks pretty good, there is serious damage throughout the plane (the radio compartment got damaged by the battery, for instance). All 3 gear mechanisms are trashed. But, I should have it going again in a couple of weeks. It's been a fun plane to fly, so I'd hate to let it go.

randall1959

My Feedback: (11)

I used to have a pickup with a CB radio and 100 watt linear amplifier. One day a fellow was flying and standing behind my truck. One of my ratchet jaw buddies was on and I thought I'd do a little talking while waiting for the freq pin. This man's plane started doing all sorts of weird gyrations till I unkeyed the mic. He was on channel 32. Some cb channels really mess with our tx's . That could be your problem. A good linear amp will not run into your receiver, but the carrier can cover up your tx in the right circumstances. I was basically putting up a wall of static right over his tx and covering up his signal to the plane. I know a club in faucett missouri that's near a truck stop and they get some glitches on certain channels. I can give you the club presidents email addy and he can give you the info they found and maybe which channels to avoid.

randall1959

My Feedback: (11)

If that quarry is open to that end of the field and they are using linears that could be what's causing the radio problems. If the quarry is open to that end of the field and has a wall on the other side, it could be directing the full power of the cb's on the equipment like a big magnifying glass.

DBCherry

My Feedback: (4)

There are also radio controlled cranes (usually in large industrial plants) that are allowed to use the 72 Mhz frequncies. They fit in between our channels, but could bleed over.
Dennis-

randall1959

My Feedback: (11)

That's also a good idea but I am not sure there are many radio controlled cranes in quarries. I'd go down to the quarry and ask about that and if they are using high powered cb's.

jamesg33

Very interesting. I was flying on channel 40, if that makes a difference. The quarry opens at the end pointing away from our field. The edge of the quarry is about 75 yards inside of their fence line (I found out looking for my plane). There is a wooded area between the fence and the cliff edge. Turned out my plane went down about 40 yards on our side of the fence. Whenever I've had radio "hits", where the plane just wiggles a little, it's always been at that end of the field (at least 5 times that I can remember). I always attributed it to the plane, as I had to double back the antenna in the fuselage (the radio gear in the Patriot is just forward of the horizontal tail) and none of my other planes have had problems (but they'e all on other channels).

The guy who suggested CB interference also said they may be using amplifiers to get the signal out of the quarry.

Hopefully, they're not doing radio controlled blasting..............although I have noticed that every time I hit my gear switch there's a loud BOOM from that direction! (Tee! Hee!)

randall1959

My Feedback: (11)

I sent you a pm. You might want to contact this fellow and ask him what they found out about their hits at the field. If memory serves me correctly, the higher the channel the more trouble they had.

antslake

My Feedback: (1)

Thats a pretty funny statement. Could you explain how a wall of static can block a radio signal without "getting into the reciever"?

I used to have a cb with a 500 hurricane amp, and it would set off all kinds of stuff, house alarms, car alarms, come over radios in stores. One day a guy one a moorcycle was passing me with his radio blaring, and I could hear myself as clear as a bell coming over his speakers. I started shouting to him " hey you, you on the bike" you should have seen his reaction. The thing would light up a 4ft flourecent light bulb, just by holding it next to the antenna. 500 watts of durty power will bleed on to just about any frequency within a 1/4 mile. Your little 1/4 watt transmitter doesn't stand a chance of over coming that interference. Its signal wars!

A friend of mine had a sweet 16 amp, 1600 watts of power, and used to open the coin operated toll gates on the Throgs Neck bridge, just by keying down, and saying the word "audio"!

If there is a quarry next to you flying field, there must be trucks there. Most truckers run a little heat, plus they over modulate their audio, which makes the signal dirty, and definately glitch you.
Was it a PCM reciever, because thats all I would fly next to the quarry.

randall1959

My Feedback: (11)

Actually you can throw up a wall using enough RF power. It's called "jamming" and the military does it all the time. You don't have to be on the same frequency. All you gotta do is throw enough power over most any transmitter and it can't get through the carrier wave of the jamming device and the "jamming device" in this case can be a CB radio. The fellow I was "jamming" unintentionally was using a pcm radio.

Montague

When the plane "glitched" in the past, did you ever hear the throttle kick up?

I generally think a crash can be put down to radio interference only when there is obvious interference, or when everything else has been eliminated. If you have an occasional wing rock, or nose dip at that part of the field, you could have thermals or turbulance from the wind rolling over an obstruction. My field has a couple of spots that will make many small planes go "nuts", in fact, I've been flipped almost inverted. But it's nothing to do with radio problems, just a very nasty bit of ground when the wind blows in just the right direction.

On the other hand, almost every case of real interference I've seen or experienced has some with some changes in throttle, jerky increases or decreases in power setting, since it's pretty much impossible to interfere with just one or two controls at a time, it's an all-or-nothing thing.

Not saying it wasn't interference, just saying that there are lots of things that can look like interference that aren't.

jamesg33

I fly this plane at full throttle all the time so did not notice any throttle "hits".

Our field is located on an old garbage dump, and is the highest land mass in the area. We've got trees, steep hills, humps and bumps all over the place - and usually lots of wind. It's one of the most challenging sites we have in the area which is why I like to fly there. In over 7 years of flying I've flown in some horrendous conditions and know exactly what you are talking about when it comes to squirly winds and their effect on small planes.

What happened to my plane was definitely not that. I was carrying plenty of speed and the conditions were perfect. I have a lot of expo dialed in as full stick throws at speed will make the plane do wild things. That's exactly what happened. the best way to describe it is that it started "darting" all over the place, and in fact crashed in a direction completely opposite my original flight path. The speed at which it darted far exceeded anything I've ever experienced with just air turbulence.

flash over

Hey Jim, sorry to hear about your crash.If you remember,my spad went in down there as well last spring,and they were working that day as well.Although I attributed my crash to a wing fold,due to aftercrash investigation,haha,I didn't see the wing fold.By the way that A-8 plug you gave me works great.I'm going to buy an extra to put in my box to repay you when I see you next.

jamesg33

Walt:

I was fortunate that the Patriot lasted as long as it did. I've had many close calls with it (for other reasons, usually pilot error). After talking with other guys at the field and thinking about it a bit, I'm beginning to think the plane had a problem, or at least was succeptable to problems from stray signals. None of my other planes have had problems, and I seem to recall the Patriot doing some uncommanded wiggles over at the Boeing Field during one of it's early flights. At the time I was flying it without exponential, so figured I had just over-controlled it. It's all starting to add up now.............

Saturday was a bad day for me. Just prior to crashing the Patriot I lost the canopy off my Duelist during a high speed pass and couldn't find it. It looked like it exploded when it came off anyway, so there may not have been much left. Anyway, just one more thing to fix! It'll be tough to find a replacement.

By the way, that glow plug is a "traveling" plug. Keep it in your tool box and give it to someone who needs one in the future. Ed V gave me one many years ago when I couldn't get my LT-40 started (he got me hooked on OS #8's!)

See you at the field!

Jim

Muxje

I like the idea of that! [8D]

flash over

Hi Jim!
You know your set up better than anyone, but if you remember we had problems all summer long with the club trainers, and I seem to remember other members complaining about their planes making uncommanded movements as well. I remember reading in the back of this months Model Aviation magazine something about all VP's having a scanner that can be borrowed and there is one in St.Charles.What do you think?
PS That plug is now available to anyone at the field who needs it.(As if it wasn't already).

scottrc

Glad to see it stayed in one piece. Not too bad, at least it wasn't going 100 mph., 10 feet off the ground, and its pilot decided to do a few rolls and got confused on his elevator inputs.

Never saw so many little pieces in my life.

Hope you guys find your source of interference.

Scott

CafeenMan

If you're getting as many hits as you say you are, then you may want to get a new frequency. Is anyone else having the same problem? Is there anyone who isn't having the problem? Find out what frequency he's on.

1bruno

Jim, I was woundering if your in the market for a new patriot? Ihave one that has been flown twice, made up like a thunderbird, you interested? if so Ill send you some photos

PLANE JIM

My Feedback: (109)

was that crash five years ago? I hope he has it flying by now -and ditto on the patriot-I got one new in the box that I will sale cheap

mjfrederick

On the rebuild you may want to consider repositioning your receiver at least. Doubling back on the antenna effectively reduces the length, causing reception issues. The length of the antenna is specific to the 72 MHz (or 2.4 GHz) frequencies, and shortening it will reduce the range.