Hatz Biplane Association

Hi Hatzers,
I was wondering what the purpose of the spring on the elevator horn is. My guess that it makes it easier to hold the stick back when taxiing might be an oversimplification. Did everyone with finished planes use it?
Al

Al,

I've not finished my Hatz yet but plan to install the spring, unless conventional wisdom here indicates otherwise. My understanding of it on other airplanes is that its function is to hold up the weight of the elevator causing it not to "droop" in flight causing the plane to pitch nose down. Of course the trim tab can also accomplish this but only if it is deflected some, which causes some drag. Now in the case of a Hatz which is basically a flying drag device, perhaps the drag from a deflected trim tab hardly matters. As you noted, the spring also helps keep the stick in a neutral position with little/no airspeed, such as taxiing. It keeps the stick from trying to pull your hand forward, or you having to reach forward for the stick each time you let go of it with no airspeed.

I wonder if that is something that I left off my Cygnet. Although the flippers are a bit smaller than on the Hatz, Holding the stick during a long taxi is a pain. The plane also always flies with some up trim and the nose drops on power reduction. I always blamed that on too small a horizontal stab, low thrust line and cg a bit forward. I will use the spring on the Hatz.
Al

Hi Al,
On mine I did not use the spring, and I've been happy with the elevator feel. I don't think you would feel it in flight, but on the ground I'm sure it would help with the back pressure. I personally don't find holding up elevator on the ground an issue, but I don't taxi too far. SN-400 is now based at 2NK9, 2800 feet of grass, flew her today. Hope to see you over the summer. Herb