This is inexcusable. This problem appears to be popping up everywhere, with 8 channel receivers too. http://www.runryder.com/helicopter/t427916p1/
http://www.flyinggiants.com/forums/f...tml#post453283

I sold all my PCM equipment, and now I'm stuck with stuff that won't work this summer. I live in the desert at high altitude. The sun here BAKES! Even when it is 60 degrees, if you are in the sun, it feels like 90. When it gets to 90 real temp, the sun is almost unbearable, but the old equipment worked. Futaba needs to make new receivers, and offer a free exchange program - AND DO IT FASST!!!!!!!!!!!!!!!!!

Guys.
We need to get this in context, the sky is NOT falling.
Lets look at what has been reported.
We have a handful of failures in Arizona and one or two others in very hot places.

All of the failures (as far as I can tell) are in large prop aerobatic models with large canopies and the rx’s in the canopy. Other flyers in hot areas such as Florida are flying jets with no issues reported (as far as I know).

Reported failure temps of the RX body is 167 F. 75C.

This is not ambient air temp but the temp the rx has got to by radiant heating through large transparent or semi transparent canopies. Basically the greenhouse effect has cooked the rx. I also wonder if the large curved canopies are acting in some way as a lens and concentrating the suns energy (magnifying glass and paper!)

We also know from work done by a German guy called Jurgen that the temperature rise on an rx from above ambient by its own heat generation is nominally 9F or 5C.
So whatever the ambient temp of the air is we get another 9 of 5 to add to it.

So if the failure temp is 167F/75C without any radiant heating or greenhouse effect the rx can take an ambient temp of 158F or 70C.
Now this is bloody hot! Where in the world does it get to those temps naturally? (And would you be out flying?)

Just looking at the 70C for a moment and put it into context , the highest ever recorded temp on earth was 56.7 °C (134.0 °F) Death Valley, California USA 10 July 1913.
(Ref: http://en.wikipedia.org/wiki/Extremes_on_Earth ) remember this is air temp and does not include greenhouse or concentrating effect behind plastic or glass covers.
For most of us in the world a very hot day is to 35C / 95 F if we go to extremes lets say 50C which is 122F we are still nowhere near the required ambient failure temp of 70C 158F. (The highest ever recorded temp in England / UK was 38.5C in 2003).

I did tests myself today on two models, Hawk and L39.
The Hawk has a canopy floor and the RX is about 3 inches below that.
Picture 1 shows the ambient temp today was 29C/84F
I placed the thermocouple on the rx body and recorded only a 1 degree rise in temp (without the rx on) to 30C/86F.
The L39 has an open canopy floor with the rx fitted to the side of the fuselage below what would be the canopy floor, so potentially it is worse than the Hawk.
Pic 2 shows the temp recorded at the rx 31C/87.8F. A rise of 2 C only (without the rx on). It can be seen that the lack of floor and the greenhouse effect has doubled the temp rise. (Very simplistic but you get the point).

So for those of us flying in temperatures up in the 50C/122F area, the first thing to do is remove as much of the radiant heat capture as possible.
Get the rx out of the canopy and under the canopy floor. Consider covering the canopy with a white cloth while standing in the sun.
I agree that some radiant energy will still be present in the cockpit and that in turn will warm the structure etc.etc. But it is not going to get the rx up to the kind of temperatures needed to fail.

We know from posts that Futaba are looking into this, but until they conclude, I see no reason why we should not all continue to fly, most without any changes and some of us with some minor alterations.
For the rest of us not living or flying in these extreme temps I propose that you just go and fly!
I did today, all 3 FASST models (2 Jets and 1 Prop), one with a 14 channel rx, one with and 8 and one with a 6. All performed perfectly as normal and I had a great day.

definately agree with Gray here........seems the only problem are from those who have placed their Rx's in an area of the aircraft where you are just asking for trouble.

the other fact here is that with all these posts, this thread is sure to be deleted or locked without many of the questions having been answered.

i was never trying to "rag" on futaba, i still like my 9c and plan to keep it, just using my pcm stuff again cause i dont trust the 2.4, i had it fail in mine first hand, so i know whats its like personally, my pcm receiver works in the same exact spot i had the 2.4, i flew all last summer in tucson with the pcm in my yak and no problems, now, at the end of april i had a 2.4 fail, same location, same way mounted as the pcm was, and its was only in the mid to upper 80's outside at the time, its only gotten hotter already in the last 3 weeks since i switched back, pcm is just fine, i am just concerned someone may loose a 40% plane into a crowd of people, i dont want to be there myself, i know japan had a holiday and people were closed for a week, but it has been 3 weeks since i started my post about my failure, and someone gave me the link to fg's thread that was already pages long at that time, so i kinda think there was enough time for some sort of warning to be issued at least, i know they dont just want to recall everything and replace stuff hap-hazardly, but there is an issue, its not isolated, there is people in az, california, and utah, which is where the warmer weather is already here, do you want to wait until people in the midwest report the same problem? if it happend to you personally you might feel different about it, i am using my 9c and will continue, just concered for fellow flyers, maybe under the canopy isnt the best spot, but no one ever warned me about it, alot of planes have a little tray there buy the rudder servo area just for the reciever, so there is a ton of us putting them there, thats all im saying

I find it difficult to believe that the Futaba 2.4 Rx is constructed significantly different from other Rx produced by Futaba. Sure it operates on a different frequency and uses the Fasst system but it would be built using existing technologies and methods that are common to other frequency Rxs. Has any one tried exposing to excessive heat other frequency Rx and or Rx from different manufactures? It is very possible you will discover the same failures due to the same cause, excessive heat.

I suspect people are fearful of new R/C system. How many supposed 'shoot downs' from the past were actually equipment failure caused by excessive heat or what ever?? Who knows.

Cheers

David

When you do research you need to not only identify the problem but then you need to construct a solution. If there is a heat problem then defining what exactly is being affected and what to do about it might take 3 weeks.. maybe longer?
Until then MOVE the reciever into the shade. How hard can that be unless You have a carbon body then that might make it difficult to find a suitable place. If that's the case then shielding within the canopy might be possible as Gray suggested. I'm flying the 2.4 and so far.. no issues. I also put my recievers inside the aircraft..

Hi Ted,

Since no one seems to understand that this is a forum for only Bax and me to answer questions about Futaba products, and not a "discussion" forum, I am locking this until we get word from Japan.

If any of you would like to further discuss this, you can use the General forum...


Krysta