SonexBuilders.net

Hi Guys,

I finally got the tail on my Onex and set the plane in the three point stance. During the early building I was considering a geared engine and therefor installed a custom landing gear to raise the front approximately four inches in level attitude to allow eight extra inches in prop diameter.

Now, I am using the largest tail wheel Sonex provides and have adjusted the geometry of the tail wheel spring to raise the rear of the plane approximately 4 inches as well, I think.

With no engine hung and no pilot, just the fuselage, I am seeing about 7 degrees deck angle. Can any of you Onex guys confirm that I am in the ball park with this deck angle?

Thanks for Your Time

Hi Wes,
I sent you a private message.

Hi,
I measured my deck angle this afternoon and got 6.5°.
During the build, I moved the mounting point of the tail spring upwards so I could remove the bolt without cutting through the lower longerons. I also installed the 6" tailwheel assembly and all this resulted into a rather shallow deck angle.
Therefore, I cannot make a threepointer just above the stall speed because the tailwheel will hit first if the speed drops below 48 kias.
Planning to replace the 6" tailwheel with a 4" one soon iot to lower the speed during flare.

lgsievila wrote:Hi Wes,
I sent you a private message.

Thanks. Got it.

dirkverdonck wrote:Hi,
I measured my deck angle this afternoon and got 6.5°.
During the build, I moved the mounting point of the tail spring upwards so I could remove the bolt without cutting through the lower longerons. I also installed the 6" tailwheel assembly and all this resulted into a rather shallow deck angle.
Therefore, I cannot make a threepointer just above the stall speed because the tailwheel will hit first if the speed drops below 48 kias.
Planning to replace the 6" tailwheel with a 4" one soon iot to lower the speed during flare.

Thanks Dirk. That is just what I needed to know. I did look at the top print of the Onex drawings and extended the lines and measured the angel. Based on that I lowered the tail just a bit. I now have eight degrees of deck angle.

I too have the 6" tail wheel and drilled the (lowest) hole to pin the tail spring such that I would miss the longeron. I now have a hole in both sides. I can switch back to seven degrees if needed.

This pic shows the Sonex supplied weldment clamped to the rudder. Looks like moving the hole upwards raised the tail by about 3/4".



Deck angle at new setting.



BTW, your plane looks awesome!!

Thanks Again.

Love that red.

Shallow Deck Angles

My Onex has the "stock" landing gear, upgraded 5:00x5 tires and the Sonex 6" tailwheel. I would guess the taller tailwheel is cancelled out by the larger tires.

Long story short...….I find the same issue that Dirk reported......to do a "full stall 3 point" landing the tail wheel always hits first. I use to have the same problem with my RV-6.

A 4" tailwheel would help my increase my "deck angle" (a good thing) but I wanted a larger tailwheel for the VERY long taxi at my airport. Most of the time the "active" is RWY 26 (7200 feet) which requires an 8500 foot taxi 80 percent of the time.

I have not measured the deck angle but next time I am at the hanger I will check with my "smart level".

Gordon.....Hummel 2400.....Onex Hobbs....15.9 hours