I'd like to venture a question in that regard. Are the 2.4 receivers more sensitive to "power failures"?

We've always had this problem in our radio systems, even when all we had was simple 4.8v nicads. For a long time the largest flight battery we had available was a 600or 800 mAh nicad and when the voltage fo those dropped from around 4.2v or 3.8v or so we would lose airplanes. At the time few planes used more than 4 standard analog servos so those batteries usually managed to make 4 flights or so before calling it a day. 6 flights was pushing the limit hard. That's why "field charging" came about.

So in todays aircraft we are using 5 or 6 high torque, or more, high current servos. Larger batteries as well but today's servos are far more "hungry" than those in the old days. Deflections are greater, planes are heavier, flying style is more agressive, so battery demands have increasd tremendously. Whne the battery voltages drop down to a certain point the receiver can no longer send an activation signal and some juice to the servos. Same as the old days. The difference is that the receivers in use today stop doing the job at a lower voltage than when they stopped working in "the old days".

Nothing's truly changed with the exception of the new receivers being able to hang in there longer than they had been able to do so 15 or 20 years ago. We've placed a greater load on our batteries and typically few sit down and perform even a rough calculation of how much current their servos might use for a given flight. Used to be we considered the idle current, normal load current, the stalled current, the average flight time, and did some basic math to determine what size battery we might need. Then we checked the battery condition after a flight to verify our calcs. Then we field charged to assure that we never ran out of that electrical fuel. We still lost planes to "brown outs" but the number was significantly reduced.

Today many simply post a question is a forum asking "what size battery do I need", or "how many milliamps". Then there's a disagreement about an answer and a free for all ensues with regard to what type battery they should have. Most go with the smallest, lightest, cheapest, minimum AH battery the can lay their hands on. Less weight you see. There's no consideration for wire length and voltage drop. Increases in resistance? What's that? Connector counts from numerous extensions lower voltage to servos and increase resistance, generating heat and reducing battery efficiency. Most forget that the battery is the second "gas tank" they carry in the plane. When the liquid one goes empty they can glide home. Not so when the electrical tank goes dry.

It's all the same as it was, we just aren't as vigilant as we used to be. When the inevitable happens the first thing everyone does is blame the radio manufacturer for designing a sub standard system. The manufacturers did a wonderful job, especially considering what we ask those radios to do. The receivers don't drop out until at a lower voltage than they used to.

We're the ones that are causing the failures. We pay less attention to our systems than ever, and have "dumbed down" the knowledge needed to participate in this hobby to a point where simple failures of basic components are assured.