Author Topic: Heater aux, rear cabin area  (Read 592 times)

Doug Johnson 1

Heater aux, rear cabin area
« on: November 25, 2017, 12:46:08 PM »
In the previous post I saw these two comments below on the Helio cabin Heater. A topic that catches my interest because of  spending some time on it,

By rmartell
I am interested to see what other 295's have done with respect to the exhaust, and baffles, with particular attention to the fresh air intake and heat muff discharge. It would appear that the system I am bolting on is insufficient for heat and a suggestion to add a second heat muff on the right exhaust may be beneficial. However, the problem is the two fittings on the firewall (one large, one small) and the problem with exhausting the hot air around the baffles when not using the heated air.

By airshiptv
I believe the 1400 series had a second muff on the other exhaust for a rear heat outlet.   It is on our 1700 factory Tri Gear.  We had JAARS do that to our 1200 U10D.  They added the bulkhead, cable operated, shut off, the tubing and the floor fitting.  It works.

I decided to open this as a new post and add some comments.

While putting c/n 1233 together at Spartanburg in 1994. I had access to Larry Montgomery’s parts collection. While searching for a part, I ran across a Rayjay/Riley turbocharger and noticed a left side exhaust with a heater muff on it.  I remembered practically getting frostbite on my feet while taking a winter ride in a Helio, so I immediately saw the potential of an added cabin heat source.

I found the 337 below while looking through all the FAA files, sometime around 2011, of aux ht installation in 2007 on Wright Airs Helio c/n 1417 and c/n 1431, this was long after I owned a Helio. I added it to my 337 collection.

This is kind of an easy way to add extra heat to the cabin but it goes to the front area keeps the pilot warm but doesn’t help the poor souls in the back seat especially when the outside temps are well below zero

I first looked at adding another opening to the heater box and then decided to try to figure out how to run a duct to the back seat, I never quite figured out how to do it then after I replaced all the insulation with sound proofing foam and sealed all the air leaks, I decided I could get by without added heat especially since I rarely had passengers in the back seat during my minimal winter use at below zero temperatures and was usually dressed for close to outside temperatures, it is a really stupid to have to make a forced landing on a winter day, lose your winter clothes in the baggage compartment or even back seat, for whatever reason then freeze to death because you are dressed for summertime conditions. Somewhere in a previous post I made a comment about rear seat heat and someone sent me the photo below but they didn't take a picture the under the floor ducting also below is a photo of the different model heater control boxes.

I noticed the rear seat heat is a Factory option (under w in the option list) so the rear cabin heat could be installed as owner operator with no more than a log book entry that your installed the Factory optional rear heat. I don’t think a lot of Helios have the rear seat heat option which appears to be available in 1970 with c/n 1433. I’ll add the Factory option list at bottom.

Below is a couple of pictures of c/n 1459 the owner used a NACA air inlet opening for the heater and moved the fresh air inlet scoop behind the firewall, I assume he did this to make ducting and cowling removal simpler. I bought the plastic NACA air inlets but never got around to installing them I was going to use one on each side for heater air inlet and the fresh air inlet. I would imagine adding a third duct for fresh air to the top of the heater air box would be relatively easy when using the fresh air inlet used on c/n 1459. It would then be even easier to use the fresh inlet at the left front of the cowling for additional heat. It would be a permanent and not a seasonal addition heat source like 1417 and 1437 it wouldn’t take heat to the rear seat and would not be the same as the Factory’s installation and would require a 337.

It would be nice to see a picture of the bulkhead, cable operated, shut off, and the under-floor ducting/tubing as installed on c/n 1719. An exploded view as shown in the parts catalog would be nice I will post the exploded view I have the rear seat heat option isn't shown in my copy of the parts catalog the only place it addressed is on the instrument panel as a push pull cable for rear seat heat control. Also below is a photo of openings in firewall a picture of  the opening for rear heater opening would be nice.

Bob M. any chance of a copy of the 337 used to install the rear heat in N5387G c/n 1257 and pictures of the important parts like opening in firewall and shutoff and underfloor duct? I would like to add this 337 to my collection.

Jim M. hope you read this far and make any needed corrections. Also do you have a parts book exploded view page that shows the rear heat parts?

« Last Edit: November 25, 2017, 01:25:49 PM by Doug Johnson 1 »

Doug Johnson 1

« Reply #1 on: November 25, 2017, 12:57:49 PM »