Loop with AeroVee

[mike.smith]

So I've done a few loops now, but none seem to be too good. I don't think I know how much back pressure to maintain, and how many G's I should be pulling through the first half of the loop.

I've been diving for 115 kts at WOT and then pulling back firmly but not fast, and then just holding it back. But I feel like I'm losing more speed than I should getting to the top. When I got over the top I pull back the power to avoid overspeeding. In the Super Decathalon I was taught to dive for speed, then 'yank' back on the stick and hold it forever. The Sonex is so quick on the controls I'm afraid I'll rip the wings off if I just yank back the stick.

But I think what I'm doing is not pulling back quickly enough, losing too much speed before the top, and then maybe holding the stick back too long over the top, as I feel like I'm mushing. At the end of the last loop I also lost a lot of power from the engine. I tried pushing the throttle forward as I leveled out, but the engine nearly quit. I had to reduce throttle to get it back to life, so I'm thinking perhaps I'm pulling too many G's at the end and it's acting like a fuel pump and forcing too much fuel to the carb (AeroInjector), flooding it. Just a guess.

I've been doing this up at 5,000' so I've had altitude and didn't get too flustered, but it sure got my attention for a while. I've been doing this over an abandoned military airfield just in case :-)

Any insight would be appreciated. BTW, aileron rolls work great. I could do those all day long :-)

Mike Smith
Sonex N439M

[Bryan Cotton]

Mike,
My acro instructor divided loops up into quarters. First quarter pull hard. You probably need at least 3G for a decent loop. Second quarter the G continuously gets less because your drop in airspeed needs less G to hold the radius. Third quarter is the inverse of the second. Last quarter is where you pull again with similar G to the entry.

I have never flown a Sonex, so hopefully somebody with more relevant experience will speak up.

All my acro flying was behind a CS prop, so I never had to worry about RPM. I would think you would not pull back the power until you were mostly established on the down line, rather than right on top.

[N111YX]

I usually dive to 150 mph for a loop then perform a 2.5 G pull at full power. Relax the pitch towards the top but keep it positive all the way around. Reduce power significantly on the downline. It's more of a cursive "l" than a circle but the "G" loading is minimal. You may find that you will not (or barely) enter the yellow range of airspeed on the backside most of the time. If it all goes to heck at the top, chop the power and release the controls, keep calm and pull out of the dive. With many aerobatic manuevers, excessive speed is your enemy. A hesitation can put you over redline quick. Get some instruction if you have not already...

"EDIT" I have never performed this maneuver with an Aero-Vee, only a Jabiru 3300.

[Fastcapy]

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[mike.smith]

A friend of mine who has flown and won many aerobatic comps in both sportsman and advanced category has flown behind the aerovee doing acro. He said outright if you want to do anything decent to dump the aerocarb as it is to difficult to control the mixture throughout the G range. Otherwise he thought the aerovee sonex was a decent airframe for acro, just didnt like the motor flooding out pulling g's.

That seems to jive with what I was experiencing today. I'm not planning to compete, and the AeroInjector is working great right now, so no plans to change. But it looks like I need to modify my technique. I wasn't anywhere even close to overspeed on the downline, but I think that's because I was pulling too much, and didn't actually allow it to round out.

I've gotten some good input. Anyone else have some helpful hints? The Super D was easy. Just pull hard and hold!

Mike