Hi all, This is my first maintenance post. I want to replace the instrument cooling hose that originates at the nose scoop. Is there a proper material & type of hose to use? Is the hose suppossed to continuous from the scoop to the firewall?
N206RG 1967. I'm based @ KBEH in MI.

You might look for a part # in hte Parts Manual under the Tech Tab on the Home page - that's where I find stuff like this. Takes awhile to get used to finding exactly what you want but the PDF is searchable and sometimes that helps.

 

Pat, Thanks for the information that the Parts manual can be searched. I had no idea! I have just been going to the table of contents, then perusing the section of interest. I did not know a PDF reader could actually "find words" in a copied document like that. This will be a big help to me. I did know the part number of the hose. Is there a way to find more of a description of that part number other than what is listed in the parts manual? I have heard from another Twin Comanche owner that it is just a thin walled black plastic tube.

Timothy, Thanks for your comment. I believe the hose I am looking for originates above the scat tubing hose. Let me know if you find out more about what the instrument cooling tube might be made of.

Gomer,
I would suggest that that equipment cooling port be capped from the nose scoop, the long run hose or pipe, depending on your serial number, be removed, and a proper equipment cooling fan be installed in on the nose compartment "firewall" and plumb it appropriately to your radios. With the ram air system, it simply provides air to a tube with some holes in it that blows somewhere near the radio stack, which is not sufficient for cooling today's modern radios that are designed to be used with forced air cooling. It also is useless on the ground, when the heat in the cabin is greatest and your radios are under e most stress! Unless you are still running MK12A's, you need forced air cooling!

Zach

Hi Zack, Thanks for that suggestion. Patric Barry had also suggested I get rid of the hose. He mentioned that when flying in colder weather, he would feel a cold draft~ He finally figured out it was coming from the ram air. My avionics stacks do have a cooling fan. I will have to see if the hose is leading to the fan, or if the fan is just using air from inside the cockpit that is not coming from the cooler nose area. My hose is torn up near where it is on a leather hanger, so it will be easy to remove.