ORIGINAL: bkdavy
Technically speaking, in order to have a fully redundant system from a reliability standpoint, we should have two completely independent control trains. In other words, two batteries, two switches, two recievers, and they should be from different manufacturers/designs. That is to further reduce the likelihood of a "common mode failure" experience by two identical components in separate trains.
Since we don't have any real probability numbers, or failure rate data for any of our components, we are left with qualitative statements about "the most common source of failure". Some believe LiPo batteries are the most likely failure. Others think switches. Still others think servo connections. Bottom line is that for the basic trainer setup, there are enough of them flying with just a standard setup (one battery, one switch, one reciever) to demonstrate they are reliable, and good preflight checks will reveal nearly any failure in the system (regular voltage checks, known battery discharge curve, range checks, routine assembly procedure, inspection).
The most common failue IMHO is the loose nut holding onto the transmitter.
Brad
LOL, yes that is indeed the main cause of failures. It often masquerades as "interference"
Well at least at my airfield.
I will reinforce the point I made earlier, the humble switch is the most overlooked component in the entire planes power system.
We spend hours trolling the net and LHS's to find the right servo for each control element, we are eligious in our brand devotion to TX / Rx manufacturer, we even go so far as to re glue an ARF that for all intents and purposes wil remain glued no matter howunskilled we believe the hands that made them are..... but we spend bottom dollar and 30sec in LHSwhen selecting the humble switch and even less time installing it.
I have seen planes with a toggle switch on the top of the wing. The toggle swithc had a light spring and the Off direction was toward the tail....