The International Cessna^® 170 Association

Ok. So we have the plane apart for its annual and I am learning all sorts of neat things about my new 170. Take a close look at this heater box. Is this the original or is this some sort of add on?

It's not original, never seen anything like that before. Anything in the logbooks about it?

Mike,
One of the improvements in the 170's after 1952 was the heater manifold that ducted heat to the right seat and the back seats rather than just to the pilot's feet. It looks like someone tried to update your heater. The later models also changed the heater shroud around the exhaust muffler and the ducting in the engine compartment. Here's what the IPC shows for the heater valve on the '52. Does yours still have this?The other thing you might want to add during annual is a stall warning buzzer and light; it's a required item on the '52.

Knowing the year modl of your airplane wold be helpful, There were changes in that part over the years of production.

Gary,
It does have that on the firewall. I will try to get a couple better pictures tomorrow.

It's a 1952 170B.

That is definitely home made. Probably trying to distribute the minimal heat better in the cabin vs burning off your pinky toe.

n2582d wrote:The other thing you might want to add during annual is a stall warning buzzer and light; it's a required item on the '52.

Gary is right. Starting with the B model the stall warning system was required. But it does not require a light and so it does not have to be in the instrument panel. Just a audial buzzer. After serial 26996 the buzzer/light was mounted behind the glove box.

The standard for this year was a horn in the panel with a light bezel in the middle that many don't know is actually a light. It was mounted in a 2 -1/4" hole to the left of the pilot yoke bearing above the radio stack.

My stall horn works and is mounted behind the instrument panel.

Bruce Fenstermacher wrote: that many don't know is actually a light.

That's because it doesn't really throw any light even when it's on. I thought the bulb in mine was burned out because I didn't see the light go on. I screwed off the lens and saw that the bulb lit when the buzzer sounded. So I cleaned the lens and took it into a dark room. When I shined a strong LED flashlight through it, I could just barely, and I mean barely, see light through it. The lens is made of what appears to be roughened red glass that hardly transmits light.

Check the bulb. Possibly you can get a different output bulb to fit the socket.

John

Thanks John. I tried putting a few different higher watt incandescent bulbs behind the lens in a dark room (using a socket and power supply) and none of them made a difference. Then I tried a few LED bulbs and they worked a little better, but the ones that fit were uni-directional. In other words, they just projected a beam outward so you needed to look at the lens head on to see any difference. Bottom line was they didn't improve it enough for me to think it mattered. I never look at the stall warning when it goes off anyway. (Who does?). It was an exercise in curiosity more than anything else.

The light is laughably ineffective. Not only is it invisible in daylight, it's hidden behind the yoke shaft. And who'd be looking down there in a low-airspeed situation, anyway?

If it turns out that your heater distrubition duct is other than as built and there is no log record of it being "legally" changed, perhaps it might be a good idea to not talk about it too much. If some eager beaver starts questioning it, you could wind up having to spend a bonch of money either changeing it back to original or hiring a DER to do a lot of paper work for a post installation approval.
If it was mine, I believe I'd scrub (delete) this whole thread.

Maybe they were trying to do something similar to this?

http://cessna170.org/forums/viewtopic.php?f=24&t=10951

Been busy with other things but finally got a chance to get back to the heater today. After some thought I decided to remove it just so I don't run into any issues down the road with paperwork. Suffice to say whoever built it must have spent a considerable amount of time putting it together. It is actually really well made. They even made a little bend for it to go over the parking brake cable and it worked really well. Pretty clever

Here's a few pictures before we removed it.







Back to stock setup.