03fomoco
Senior Heliman
Location: Tucson AZ
| How hot an Aircraft can getWe posted this over on FG and this shows how hot an aircraft gets in the sun and it was only 88 degrees ambient. This might be an issue for the scale heli guys. We are still walking a fine line with a heli on a 110 degree day...
From Flying Giants and FASST thread.
Ok,
I am in the same boat and was able to fail a 6014 on the bench at 165 degrees, so I shelved them all for now and wanted to see how hot an aircraft really got.
Testing was crude but effective for our use. I used a Fluke meter and also an indoor outdoor thermometer. First we checked the "cheap" thermometer against the Fluke and it was within +/- 2 degrees as we let them stabilize from an air conditioned car to direct sunlight. The aircraft was a Comp ARF 3m Extra with no cans and a sealed unvented fuselage.
The first picture shows the ambient temperature taken half way between the ground and the aircraft. The second shows the temperature taken from the left rear canopy mount bolt hole and the probe under the pilot head "fiberglass" light in color. The third picture is alarming and was a surprise. It was 88 degrees out and under the lexan canopy in direct sunlight the temperature was 156 degrees with an ambient of 88. Wow.
Now for a very interesting flight test right? Ok, FASST on the shelf and two trusty 149dp mounted (this aircraft was not converted to FASST). We took the temperature saturated thermometer and reset the min/max readings and secured it in the aircraft to the wing tube. At the time of canopy install the temp had dropped to 130 degrees. We waited until it read over 150 degrees again and went for engine start. The flight was uneventful.
After flight immediately after shutdown the temp reading was 127 degrees, it was now 91 degrees ambient. We pulled the canopy to check the minimum reading in flight and (ready for this) the temperature was 102.7 in a sealed aircraft, so I guess it is not that well sealed.
Conclusions, an aircraft in the pits in the sun is possibly 52 degrees cooler in the air at 90 degrees ambient. The clear canopy on the Comp ARF is murder for everything inside. An aircraft with minimal ventilation still receives a fair amount of cooling.
Bad news is it was only 92 degrees today and it will be 110 in a month or so. Then what, sadly someone will most likely get hurt before the sky will fall. I think it is irresponsible for a company not to at a minimum state something like "some consumers have experienced heat related failures and product model # jhsdfkl should not be used until further notice for safety." Furthermore they should halt the distribution of the product. Futaba is a large company and needs and wants to protect image but if someone is seriously injured image will mean nothing. I am sure they are working this and none of us are engineers on this product, but the simple fact is this product design does not meet the application requirements that past products did. In a situation like this, if it was known, education and informing the customer would be one of the first priorities.
Dave
Original thread:
http://www.flyinggiants.com/forums/...html#post453283
  
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