Ron, a few years ago there was a something published by Graupner saying that the worst and weakest link in our systems were the switches (I guess they were trying to sell something, haha)... but because of that we started doing what you mention: no switches, just extensions and a piece of masking tape to make (just to make sure)

Now we use fail open switches

I do agree with using dual batteries. Not through fancy powerboxes and stuff, just a regular JR (or whatever you fly) receiver.

Jack G

On my 46% Ultimate Bipe I was running everything through 1 receiver, but I doubled up on the switches and batteries into this single receiver. No PowerBox, no regulators, no non-essential electronics. Just seemed like a huge hassle for nothing really gained, while adding more points of failure. I was using 8611s, with unregulated Duralite Plus batteries. Roughly 8.4v off the charger directly into the electronics, for over 500 flights without issue.

My setup was:
14 x 8611
1 x 8231 (throttle)
1 x 8231 (choke)
1 10ch Synth Rx
2 x Duralite Plus 4800mah batteries
2 x JR Charge Switches
Extensions all over the damn place.

Now, admittedly I have no experience in setting up 2.4Ghz systems with their multiple receivers, so I can't speak to that, but when I was running 72Mhz stuff, the simpler I made the systems, the BETTER my Rf link seemed to be and the less headache I had with the airplane. I see people all the time powerboxes, battery redundancy systems, and all sorts of other electronics in the airplanes that I just felt was adding more headache than it was solving.

The only problem with that Ron is HOW you unplug it from the extension. Pulling on the wires can cause early failure in the plugs. If you're pulling on the plug casing itself, then there's no issue and that's about as good as you'll get for power delivery.

The question of whether was are overcomplicating our jets isn't just limited to things electrical/electronic. There is also the fuel system. I flew turbine powered planes for years in the 1990's without having a UAT (since they weren't invented yet). Some guys ran regular clunks, some got fancy and used a big felt clunk which worked great. In dozens and dozens and dozens of flights I never had a flame out due to an air bubble.

These days, if you showed up at the field with a jet without a UAT, I think many folks would figure you're nuts.

Regards,

Jim

Everybodymakes a good point and coming from a 20 year career in the HVAC trade dealing with mix matched electronics my point is this, there is entirely too much electronic bling available for us to throw at our birds,
shy of being an engineer in electronics the more stuff you throw at your bird the more the likelyhood you'll have solid state incompatability problems bear this in mind
I have had to teach myself sometimes the expensive way which controls will mesh and which ones won't and this is no different there are alot of factors to be considered
when throwing an assemblage of electronic parts together and absolutely no mfgr can possibly cover all of the possible scenarios of all the available combinations that may be encountered.
My advice is to thoroughly read an understand in intimate detail the voltages, amperages, compatibility issues and anything else you can learn and if you have a question call the 800# in the back of the book and ASK detailed questions explaining your exact setup.
being a licensed maser technician I cannot even begin to lay claim to thinking I know it all, however the best source for info is and always will be just that "the source, the people who made it and developed it and tested it" if you can verbally give them a ladder diagram with figures in and out
often times they will arm you with all the info you need to make a very educated decision on your particular setup.
The only dumb question is the one you ask yourself when you take the walk of shame

I like all of the extra redundancy and protection that modern technology brings us. I think it increases not decreases the odds of having a failure. Its allowed us to have jets that start faster, run faster, and fly better. Its all good.

Regarding fuel, I've started to use Tom Cooks UAT. Thats one thing I will never have to worry about on my jets.

Doug you are so right about how you unplug things. I also use a Parsons Products saftey clip to assure the connection stays together. I cringe seeing how some guys yank wings off pulling on the extensions to unplug things. Cycling my flight and ecu batteries right now for the first jet event for the year for me and found that my 2 year old JR 3000 mah battery is deader than Jimmy Hoffa that was in my reaction for RX and servo power.

LMAO, thats hilarious !!

I think Jeremy raises a good point. In my opinion a lot of jets have unnecessarily complicated dual systems and redundancy. It is like the old example of “Is a twin engine aircraft any safer then single engine aircraft?” Answer: only if it can fly on one engine. Otherwise the second engine has actually doubled the likely hood of failure, without adding any safety. (okay, it could extend the glide, but you get my point).

I do use dual batteries, and JRs multi Rx system, but that is the only redundancy I have in my Bandit. No power boxes and no switches, (just a Deans Plug for off/on). KISS, is my motto. If you eliminate the component, it cannot fail.

I do have a question though. Most people recommend a dual battery system of some sort inferring that our airborne batteries are a weak part of the system. Why then do we not insist on a dual battery for our transmitters.?? Surly the Tx battery is just as prone to sudden failure as the flight battery, with the same consequences. After all if the flight battery is correctly selected, sized and charged, it should be just as reliable as the Tx battery.. Just wondering why....

Roger

Because you have real time information on the transmitter battery status on the display, and even a warming beeper in case of a sudden voltage drop. Also the tx battery and connector is not exposed to the vibration and "g" forces you normally found inside a airframe.

Radio TX's are not typically high amp drawing systems and the battery is typically securely attached, no vibrations/fuel exposure etc to kill the wires and switches. In an aircraft with a gazillion servos powering large, unbalanced flight controls at high speeds, dual batteries are a very good idea in my opinion. Not just for failure scenarios of a single battery cell or switch, but for the ability for a redundant battery to up the amp capability and voltage stability of the battery system.

As per the Kinks song many of us are 'dedicated followers of fashion'.

If Quique, Shulman, Youngblood, insert gun pilot here......... starts using all these
gadgets all the Quique, Shulman, Youngblood, insert gun pilot here......... wanabees
wander off like drones to buy this stuff in the (unlikely) hope that they will fly as good
as their heros.

Me? Give me the KISS principal every time. Who was it that said 'simplify & add lightness'?

One of the major airliner manufacturers (I think it was Boeing) used the line that a twin engine aircraft was half as likely to have an engine failure as a 4 engined plane when campaigning for ETOPS operations (Extended-range Twin-engine Operational Performance Standards).

If it's not there it cannot fail. - John.

With logic like that a glider is the safest to travel in. No engine to fail....
Seriously though, battery redundancy would almost always be a good thing, as well as switch redundancy.
Two A123 packs 2 switches is as good/better than most of the current systems on offer.
LiPo no thanks.

My turbine F16 has no switches! Per above I just use my choice of plug which is the mltiplex MPX plug. Has 6 pins. You gang 3 X 3 for + and - by soldering. I run 2 batts admittedly which means I have 6 pins for + and 6 pins for -. Very simple set up and bullet proof IMO. Around 80 flights no issues and no powerbox. Back to the KISS principal. No switch and no powerbox! 2 X 8711's and 4 other digitals in there, gear and brake solenoids ECU etc.

A lot of us use dual batts RX for redundancy, but we all only have 1 batt in the TX. So what happens if the TX batt dies???? No one talks or thinks about that???? TX batts are the same technology as RX batts and can fail jsut the same!!!!!!!!!!!! To be totally honest, all I worry about when I fly is that I don't get a flame out in a BAD spot and that the gear comes down when I comand it to. It is up to the pilot then to put it on the ground. I must also say I have seen way more crashes and damage done on landings than I have ever seen form a system failure of some description or RX batt dying in flight?

MHO and 2 C! Hope this helps and my answer is yes we do!!


Mav

LOL - reminds me of a tired old joke from when I was about 10 :

SAA flight 198 heavy is en-route CPT to LHR. Over the intercom comes "Ladies and gentlemen, this is your captain speaking. We've had a slight problem with one of our 4 engines, so are shutting it down as a precaution. This means that we will fly just a little bit slower, so we will arrive at our destination 1 hour later than planned."

Half an hour later : "Ladies and gentlemen, this is your captain speaking. We've had a slight problem with a second engine, so are shutting it down too. The reduced airspeed means that we will now arrive at our destination 2 1/2 hours later than planned."

An hour after that : "Ladies and gentlemen, this is your captain speaking. We've had to shut down a third engine. This will slow us down even more, so that we will arrive at our destination 4 hours later than planned."

Van de Merwe turns to his wife and says "Let's hope the 4th engine doesn't have to be shut down too, otherwise we'll be up here all bleddy night !"

It is amazing how many folks from the Speaking family have become captains, the last couple of cruise ships I was on where run by a captian Speaking.

And yes, simplier does offer few chances for something to go wrong. If you could make a reciever out a single resistor I would buy it.

Steven

Yes, adding gadgets means more stuff that can fail.

However explain this, the crashrate at jet events (and other big scale meetings) has decimated since the introduction of powerswitches and battery-backers.
2.4GHz technology is another contribution to this, but most of the time it was the plane going dead, not a bad RF-link.

Bart.

I use a failsafe switch on a regulator that regulates dual batteries, which are usually LIPOS btw. This then goes to a EQ10 which insures constant clean voltage to my servos and RX. Perfect combinaton that has never failed me.

Yes the TX battery can fail. If they offered a redundant source for that I would use it.

The key is reducing the amount of single source failure points. If you install all of the above items correctly they the odds are in your favor against a failure not for it.

In 15 years, I had only 2 failures cause by something else then my lack of “prudence”… Once was a batteries failure and the other was a servos failure, but in both case I could had done something, because in both case I had a warning before the failure (before take off), so honestly, I think KISS is the rule…

In my jet, I just DON’T have any switch, I do have 2 lipo batt connected in a Smartfly regulator (no switch) directly in it, I plug/unplug it manually once a day and I use the integrated kill switch to “switch” off during the day, if required I charge in between the flight, but with my 2 x 2500mh lipo batt I could usually do a long run without charging…
I don’t use any Y cable, just one receiver, single servos per control surfaces…

The main reason I use a Smartfly regulator is to reduce the voltage from the lipo and I use two lipo not mainly for redundancy, but to get more spike power to properly drive all the digital servos…

So, again, KISS and pre-flight check list or inspection before any start-up or take off… Simple, but efficient…

I wonder how many people do any sort of pre-flight check on every flight? I ALWAYS check my battery voltage befor a flight and my servo movement, control surfaces etc.. I rarely have had an issue resulting a crash.

I think that the answer to this maybe a range of factors. Along with improved technologies like power boxes there has been a general increase in consciousness of our systems requirements, and in particular the air borne battery/power systems. Reasons;

1) In the last few years all models, not just jets, have tendered to be come bigger and more expensive. (people are prepared to invest more in preventing a crash).
2) The shift to 2.4 has made it absolutely critical the RX voltage remains above 3.5 volts.
3) The advance in battery technologies and more particular chargers, give us much better tools to charge and monitor our batteries.We have moved on from using a simple wall charger to trickle charge our 1000 mah Ni cads, and hoping for the best.

I know there was a big turning point for me when I moved to JR/Spretrum 2.4 a couple of years ago. I educated myself on the brown out issue (which simply requires a robust power supply to avoid) so I did a bit of basic research. I now know things like how much power my model uses in a typical flight, what each of the servos can draw when stalled, and how much capacity is available in my battery. Most of the guys here that fly jets know this stuff. I don’t think this was the case a few years back.

Power boxes are just one of the gizmos that have become available in the last decade. They are undoubtable useful in some applications, maybe not in others, but they are a part of the ongoing development of safer systems in our toys, along with a real increase in awearness on how to build a safe system.

Roger

In regards to the whole battery redundancy and TX battery failing, How many times have you heard someone say "my TX battery failed" right after a crash? After being in the hobby for over 20 years, I have heard that a grand total of ZERO times. But I have seen guys find out that their Rx battery took a crap on them in flight at least a dozen times. So what is the chances of the Tx battery dieing in a low amperage draw system, i'd say pretty slim and if it does happen to you, its just bad luck and probably a once in a thousand thing to fail. So my question is why NOT install a redundant battery in the airplane if you have the space to do so? The only thing that could happen is a possible battery or switch failure.. which if that was your only battery, you'd be out money. but if it was your 2nd battery, you'd at least be able to land and figure it out (that is if you charge after every flight).

truthfully, it comes down to each person's personal desires and opinion on redundancy. Some Like to have all the new gadgets, etc and if it makes them happy, so be it. If you have been doing things your way for years and it works fine for you, so be it.

I've been useing two regulators straight to the reciever with two lipos plugged in direct to the regulators with deans connectors
useing this on three different planes with hundreds of flights no issues

I also got into the habit on the first flight of pluging in one pack.... unplug it.. then plug in the other.. then plug them both in

that way I'm sure the regulator is working.. if I just plug one in then the next I have no way of knowing the last one is on

"Yes" ( I dont want to complicate my answer) Scotty

I can easily remember the UK display team ghost squadron's Me 262 going in right after take-off at Jets over Pampa in Belgium. The model was brand new and it was the first time to be displayed at a jet event.
Plane took off, and after about 5 seconds it was all over.
Reading out both ecu's reveiled simultaneous signal loss.
One bad NiCad cell in the transmitter was the source of the problem.

Bart.