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Old 09-08-2010 | 05:12 PM
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Luchnia
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From: Amelia, VA
Default RE: Best possible Redundancy


ORIGINAL: bkdavy


ORIGINAL: Luchnia

The best path is to pay close attention to any changes in your planes characteristics. Are there different sounds, change in vibration to the airframe, servo acting strange, was that a flutter you heard, landing gear secure, engine firewall solid, engine smooth as normal, servos solid in their mounts, all screws tight, etc.? A watchful eye and ear will keep you flying longer with much less failure and will minimize risks.
In the interest of full disclosure, I recently had an experience where the ''watchful eye'' saved my big investment (30% PRC Yak 54). I noticed as part of my preflight checks that the spinner appeared to be vibrating excessively. Further inspection revealed a cracked firewall support. Had I flown the plane, chances are the firewall would have come apart completely and I'd have lost the plane.

The only redundant system I installed was the switch. I have a single battery that goes to two switches, and both provide power to the same reciever. I subscribed to the notion that the switch is the weak link in the chain. With two switches, its easier to identify a failing switch, and by checking each switch on startup, I improve my odds of finding it before disaster. Batteries are A123 that I keep track of the capacity. Voltage feeds back to the transmitter real time, and I know my ''no-fly'' voltage.

The trick is knowing what behavior your plane exhibits, and when its different, finding out why. Does the radio glitch if the switch is jiggled? This is usually the first indicator of a worn or failing switch. Do servos glitch when wires are shaken or tapped? Is the plane vibrating more than it used to? Does it sound the same?

Brad
Great catch! Just last week I had a similar situation and I even noticed something the week before. I kept hearing a slight variation in engine sound on my Pulse XT. I have flown the plane around 175-200 flights and I heard a small but noticeable pitch/vibration change and I had noticed the week before my switch on the side had two screws loosened. I checked my engine and she was smooth as silk and really could not find anything wrong. Well, I was flying it Sunday and I went to start it and noticed that the engine seemed to move back slightly. After further inspection I saw the firewall was cracked and would move about an 1/8 of an inch.

The point of this is that the sound or change in the characteristics of the plane was giving me an indicator that something had changed. Careful inspection is vital and is the real key to save planes. I do agree that switches are probably the weakest points outside of connectors. You have to make sure your connectors are vibration free and well connected or you will soon find out just how good they are [X(]