SonexBuilders.net

My assumption of an aerobatic plane is the follow.
1. Control surfaces and Structure must be sufficent for loads.
2. Fuel system must be sufficient for maneuvers.
3. Engine must be capable of handling manuvers.
4. Instruments must be sufficent for manuvers.

1 is advertised by sonex as being true, also the plans say g good for +6 -3 (so in will assume this is fine)
2 is up to the builder, but is the stock onex design sufficent? What would be the actual limitations on this, or corrections required?
3. Is the areovee capable of this? How about the revmaster or a hummel? Again what kind of manuvers limits should one expect?
4 what is actually needed during manuvers?

I am there are other things to consider, if i missed any please post on it.

Once this whole pandemic mess is finished intend to take some aerobatic lessons, so forgive me if the answers are obvious to others.

Very Respectfully,
Matthew
ONEX #037

The answer is yes with a but. Light gentleman aerobatics like aileron rolls, loops, steep turns etc are in its wheel house. The high level stuff would be too much for it, IF the vw engine was even up for it. It does not have the capability for sustainable inverted flight. Any kind of snap maneuver would be too much. You might get away with it for a while but not indefinitely. You can have a lot of fun with these little birds just stay within the design.

Another factor is the pilot. An Aerocommander is not normally considered "aerobatic". But in the right hands.....

https://youtu.be/uhkmY3rELeY

I regularly pull up to 4.7 Gs doing aerobatics in my AeroVee Sonex. There is little difference in the basic design of the airframe of a Sonex and Onex. Loops, rolls, 4 point rolls, spins, Cuban 8's, hammerheads, are all in my list of aerobatic maneuvers.

Just keep in mind fellow aeronauts. The Onex fuel system is designed to only operate correctly in positive G's. Negative G's could cause you to run out of gas and vent liquid from the tank vent.

With regards to question #4:
1. Your eyeballs.
2. RPMs, CHTs
3. Turn/slip indicator
4. G-meter (optional)

In my experience, nothing else needed for instrumentation for aerobatics in a Onex/Sonex.

https://www.youtube.com/watch?v=FrG-_scTTrY
https://www.youtube.com/watch?v=gPzQ3Ruq8LY
https://www.youtube.com/watch?v=ctzIi77rxok

Mike,

The videos are impressive.
Did you need to modify the fuel system to support the manuvers?
Im not sure its practical but I was wondering how, if at all, the onex / sonex could stay inverted in flight. Im assuming at most ots during a manuver that causes a positive g on the airframe. But if trying to fly inverted on purpose at steady state conditions how long would be reasonable? A few seconds, not at all?
Is there a modification i should make now before i install the fuel tank that would facilitate this or is the engine and its oil sump the limiting factor?

I do not want to miss the opportunity to make a small modification now as opposed to wanting to do it after everything is done and the rework is to much to be reasonable.

Very Respectfully,
Matthew
Onex #037

Matthew,

Here's the guy you want to talk to.

https://www.youtube.com/watch?v=sCvi37XxfK8

Jeff

Onex107 wrote:Just keep in mind fellow aeronauts. The Onex fuel system is designed to only operate correctly in positive G's. Negative G's could cause you to run out of gas and vent liquid from the tank vent.

And I might add, the Onex tank vents out the bottom of the plane whereas the Sonex vents on the windshield and gasoline on the windshield results in cracks. That's why mine needs replacement.

Onex107 wrote:

Onex107 wrote:Just keep in mind fellow aeronauts. The Onex fuel system is designed to only operate correctly in positive G's. Negative G's could cause you to run out of gas and vent liquid from the tank vent.

And I might add, the Onex tank vents out the bottom of the plane whereas the Sonex vents on the windshield and gasoline on the windshield results in cracks. That's why mine needs replacement.

The vent at the bottom of the plane will actually stop fuel coming out of the vent while in negative G or upside down.